EP0687744A2 - Stickstoffenthaltende hartgesinterte Legierung - Google Patents

Stickstoffenthaltende hartgesinterte Legierung Download PDF

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EP0687744A2
EP0687744A2 EP95107670A EP95107670A EP0687744A2 EP 0687744 A2 EP0687744 A2 EP 0687744A2 EP 95107670 A EP95107670 A EP 95107670A EP 95107670 A EP95107670 A EP 95107670A EP 0687744 A2 EP0687744 A2 EP 0687744A2
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Prior art keywords
percent
nitrogen
weight
layer
volume
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EP95107670A
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French (fr)
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EP0687744B1 (de
EP0687744A3 (de
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Keiichi C/O Itami Works Of Sumitomo Elec. Tsuda
Kazutaka C/O Itami Works Of Sumitomo Elec. Isobe
Akihiko C/O Itami Works Of Sumitomo Ikegaya
Nobuyuki C/O Itami Works Of Sumitomo Kitagawa
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Sumitomo Electric Industries Ltd
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Sumitomo Electric Industries Ltd
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Priority claimed from JP10558494A external-priority patent/JP3648758B2/ja
Priority claimed from JP04929095A external-priority patent/JP3803694B2/ja
Application filed by Sumitomo Electric Industries Ltd filed Critical Sumitomo Electric Industries Ltd
Priority to EP97115279A priority Critical patent/EP0822265B1/de
Publication of EP0687744A2 publication Critical patent/EP0687744A2/de
Publication of EP0687744A3 publication Critical patent/EP0687744A3/de
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
    • C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
    • C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C22C29/06—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
    • C22C29/08—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds based on tungsten carbide
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C22C1/04—Making non-ferrous alloys by powder metallurgy
    • C22C1/05—Mixtures of metal powder with non-metallic powder
    • C22C1/051—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/1003—Use of special medium during sintering, e.g. sintering aid
    • B22F3/1007—Atmosphere
    • B22F3/101—Changing atmosphere
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/1017—Multiple heating or additional steps
    • B22F3/1028—Controlled cooling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/02—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite layers
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
    • C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C22C29/04—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbonitrides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2201/00—Treatment under specific atmosphere
    • B22F2201/02—Nitrogen
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2201/00—Treatment under specific atmosphere
    • B22F2201/20—Use of vacuum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy

Definitions

  • the present invention relates to a nitrogen-containing sintered hard alloy, and more particularly, it relates to a nitrogen-containing sintered hard alloy which is improved in thermal shock resistance, wear resistance and strength for serving as a material for a cutting tool and enabling application to wet cutting.
  • a nitrogen-containing sintered hard alloy having a hard phase of a carbo-nitride mainly composed of Ti, which is bonded by a metal containing Ni and Co, has already been put into practice as a cutting tool.
  • This nitrogen-containing sintered hard alloy is widely applied to a cutting tool similarly to the so-called cemented carbide which is mainly composed of WC, since the hard phase is extremely fined as compared with a conventional sintered hard alloy which is free from nitrogen to remarkably improve high-temperature creep resistance as the result.
  • Japanese Patent Laying-Open No. 2-15139 (1990) proposes means of improving surface roughness of a material containing at least 50 percent by weight of Ti in terms of a carbide or the like and less than 40 percent by weight of an element belonging to the group 6A (the group VIB in the CAS version) in terms of a carbide and having an atomic ratio N/(C + N) of 0.4 to 0.6 with a high nitrogen content by controlling the sintering atmosphere, for forming a modified part having high toughness and hardness in a surface layer part.
  • 5-9646 (1993) discloses a cermet which is prepared by sintering a material, which is mainly composed of Ti, containing less than 40 percent by weight of W, Mo and Cr in total in terms of a carbide, and thereafter controlling a cooling step for providing a surface part with a region having a smaller amount of binder phase as compared with the interior, to leave compressive stress on the surface.
  • each of the cermets disclosed in the aforementioned gazettes is insufficient in chipping resistance as compared with the coated cemented carbide, although wear resistance and toughness are improved. Further, the cermet is so inferior in thermal shock resistance that sudden chipping is easily caused by occurrence of thermal cracking or crack extension resulting from both thermal and mechanical shocks in particular, and sufficient reliability cannot be attained. Although the manufacturing cost for such prior art is reduced due to omission of a coating step, the performance cannot be sufficiently improved. This suggests that improvement in strength against chipping is naturally limited in the category of the so-called cermet which is prepared on the premise that the same contains Ti in excess of a certain degree of amount.
  • the inventors have made deep study on analysis of cutting phenomenons such as temperature distributions in various cutting operations and arrangements of material components in tools, to obtain the following recognition:
  • a cutting portion is partially exposed to high-temperature environment in a surface part of an insert which is in contact with a workpiece, a part of a rake face which is fretted by chips, and the like.
  • the thermal conductivity of the former is about half that of the latter as hereinabove described, and hence heat which is generated on the surface of the cermet is so hardly diffused into the interior that the temperature is abruptly reduced in the interior although the surface is at a high temperature.
  • the cermet is extremely easily chipped.
  • the cermet is rapidly quenched with water-soluble cutting oil from a high temperature state or cooled with cutting in lost motion, further, only an extremely small part of its surface is quenched.
  • the thermal expansion coefficient of the former is about 1.3 times that of the latter as hereinabove described, and hence tensile stress is caused on a surface layer part to extremely easily cause thermal cracking.
  • the cermet is inferior in thermal shock resistance to the cemented carbide.
  • the fracture toughness of the former is reduced by about 30 to 50 % as compared with the latter, and hence crack extension resistance is also reduced in the interior of the alloy.
  • An object of the present invention is to provide a nitrogen-containing sintered hard alloy which can be employed as a cutting tool in high reliability with no surface coating also in a working region under conditions bringing a strong thermal shock with no requirement for the high-priced coated cemented carbide which has been employed in general.
  • the nitrogen-containing sintered hard alloy according to the present invention is provided in its interior with a larger amount of WC as compared with the conventional nitrogen-containing sintered hard alloy in structure, to be improved in resistance against crack extension.
  • WC particles toward the alloy surface appear in the conventional nitrogen-containing sintered hard alloy to provide a tool material called a P-type material, while this tool material is inferior in smoothness of the machined surface. Therefore, this material is also remarkably inferior in abrasive wear resistance to the so-called cermet or coated cemented carbide.
  • the nitrogen-containing sintered hard alloy includes: at least 75 percent by weight and not more than 95 percent by weight of a hard phase containing (Ti ⁇ W x M y )(C u N 1-u ) (M represents at least one of metals belonging to the group 6A of the periodic table excluding W, 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.9, and 0 ⁇ u ⁇ 0.9) and WC, and at least 5 percent by weight and not more than 25 percent by weight of a binder phase containing Ni, Co and unavoidable impurities, and contains: at least 5 percent by weight and not more than 60 percent by weight of Ti in terms of a carbide, a nitride or a carbo-nitride, and at least 30 percent by weight and not more than 70 percent by weight of a metal belonging to the group 6A of the periodic table in terms of a carbide, the atomic ratio of nitrogen/(carbon + nitrogen) in the hard phase is
  • the content of the hard phase is set in the range of at least 75 percent by weight and not more than 95 percent by weight. This is because wear resistance and plastic deformation resistance are remarkably reduced if the content of the hard phase is less than 75 percent by weight while strength and toughness are insufficient if the content exceeds 95 percent by weight.
  • the Ti content is set in the range of at least 5 percent by weight and not more than 60 percent by weight in terms of a carbide or the like since wear resistance cannot reach a desired level if the Ti content is less than 5 percent by weight while toughness is deteriorated if the Ti content exceeds 60 percent by weight.
  • the Ti content is preferably at least 5 percent by weight and not more than 50 percent by weight, and particularly preferably at least 20 percent by weight and not more than 50 percent by weight.
  • the content of the metal belonging to the group 6A of the periodic table is set in the range of at least 30 percent by weight and not more than 70 percent by weight in terms of a carbide since desired toughness cannot be attained if the content is less than 30 percent by weight while a large amount of WC particles remain in the surface to disadvantageously result in insufficient wear resistance if the content exceeds 70 percent by weight.
  • the content of the metal belonging to the group 6A of the periodic table is preferably at least 40 percent by weight and not more than 70 percent by weight, and particularly preferably at least 40 percent by weight and not more than 60 percent by weight in terms of the carbide.
  • the atomic ratio of nitrogen/(carbon + nitrogen) in the hard phase is set in the range of at least 0.2 and less than 0.5, since both toughness and wear resistance cannot reach desired levels if the atomic ratio is less than 0.2 while the degree of sintering is reduced and toughness is deteriorated if the atomic ratio exceeds 0.5.
  • This atomic ratio is preferably at least 0.2 and less than 0.4.
  • the thickness of the layer hardly provided with the hard phase containing WC is set in the range of at least 3 ⁇ m and not more than 30 ⁇ m in the portion immediately under the soft layer consisting of the binder phase metal and WC located on the outermost surface since desired abrasive wear resistance and crater wear resistance cannot be attained if the thickness is less than 3 ⁇ m while no effect of facilitating crack extension resistance is attained and toughness is reduced as the result if the thickness exceeds 30 ⁇ m.
  • the abundance of the hard phase containing WC is gradually increased toward the interior from the layer hardly provided with the hard phase containing WC up to a maximum depth of 1 mm from the outermost surface in the aforementioned composition.
  • the abundance of the hard phase containing WC is gradually increased toward the interior from the layer provided with not more than 1 percent by volume of the hard phase containing WC up to the maximum depth of 1 mm from the outermost surface, whereby abrupt change of the WC content distribution is prevented in the boundary between the regions provided and not provided with WC, so that occurrence of residual stress is relieved in this boundary.
  • the abundance of the hard phase containing WC is preferably at least 5 percent by volume and less than 50 percent by volume in the interior of the depth of at least 1 mm from the outermost surface in the aforementioned composition.
  • the nitrogen-containing sintered hard alloy includes: at least 75 percent by weight and not more than 95 percent by weight of a hard phase containing (Ti ⁇ W x M y )(C u N 1-u ) (M represents at least one of metals belonging to the groups 4A, 5A and 6A of the periodic table, corresponding to the groups IVB, VB and VIB in the CAS version respectively, excluding Ti and W, 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.9, and 0 ⁇ u ⁇ 0.9) and WC, and at least 5 percent by weight and not more than 25 percent by weight of a binder phase containing Ni, Co and unavoidable impurities, and contains: at least 5 percent by weight and not more than 60 percent by weight of Ti in terms of a carbide, a nitride or a carbo-nitride, at least 30 percent by weight and not more than 70 percent by weight of a metal belonging to
  • the nitrogen-containing sintered hard alloy contains a metal belonging to the group 4A of the periodic table excluding Ti and/or the group 5A in addition to the metal belonging to the group 6A of the periodic table excluding W, at least 2 percent by weight and not more than 15 percent by weight of Ta and Nb in total in terms of a carbide, a nitride or a carbo-nitride, and not more than 5 percent by weight of V, Zr and Hf in total in terms of a carbide, a nitride or a carbo-nitride, a functional effect which is similar to that of the composition according to the first aspect can be attained.
  • Crater wear resistance is not improved if the total content of Ta and Nb is less than 2 percent by weight in terms of a carbide or the like, while chipping resistance is reduced if the content exceeds 15 percent by weight.
  • the alloy preferably contains V, Zr and Hf to be improved in strength and hardness under a high temperature, while the degree of sintering is reduced and chipping resistance is also reduced as the result if the total content of V, Zr and Hf exceeds 5 percent by weight in terms of the carbide etc.
  • the abundance of the hard phase containing WC is gradually increased toward the interior from the layer hardly provided with the hard phase containing WC up to a maximum depth of 1 mm from the outermost surface in the aforementioned composition.
  • the abundance of the hard phase containing WC is preferably at least 5 percent by volume and less than 50 percent by volume in the interior of at least 1 mm in depth from the outermost surface in the aforementioned composition.
  • Thermal cracking is caused by temperature difference between the surface part and the interior of the alloy.
  • the thermal conductivity of the nitrogen-containing sintered hard alloy itself may be improved, while the improvement of the thermal conductivity of the nitrogen-containing sintered hard alloy is naturally limited.
  • heat which is generated during cutting is conducted to the overall alloy to attain a heat divergence (fin) effect when a layer having high thermal conductivity which is rich in WC with a rest of a metal binder phase mainly composed of Co and Ni is arranged on a surface part of a nitrogen-containing sintered hard alloy.
  • a nitrogen-containing sintered hard alloy according to the third aspect of the present invention which has been proposed on the basis of the aforementioned result of the study, includes a hard phase containing WC serving as an essential element and a carbide, a nitride or a carbo-nitride of at least one transition metal selected from the groups 4A, 5A and 6A of the periodic table or a composite carbo-nitride thereof, and a binder phase containing Ni, Co and unavoidable impurities, and has the following structure and composition:
  • An exudation layer 1 containing a metal binder phase, mainly composed of Ni and Co, and WC is present on an alloy surface part (see Figs.
  • this layer 1 is internally divided into three layers including an outermost layer containing at least 0 percent by volume and not more than 30 percent by volume (preferably 0 to 5 percent by volume) of WC with a rest formed by a metal binder phase which is mainly composed of Co and Ni, an intermediate layer containing at least 50 percent by volume and not more than 100 percent by volume (preferably 80 to 100 percent by volume) of WC with a rest formed by a metal binder phase which is mainly composed of Co and Ni, and a lowermost layer containing at least 0 percent by volume and not more than 30 percent by volume (preferably 0 to 5 percent by volume) of WC with a rest formed by a metal binder phase which is mainly composed of Co and Ni.
  • the outermost and lowermost layers are at least 0.1 ⁇ m and not more than 10 ⁇ m (preferably 0.1 to 0.5 ⁇ m) in thickness, while the intermediate layer is at least 0.5 ⁇ m and not more than 10 ⁇ m (preferably 0.5 to 5 ⁇ m) in thickness.
  • thermal shock resistance is remarkably improved. While the outermost and lowermost layers are substantially rich in the metal binder phase mainly composed of Ni and Co, these layers are inevitably formed in the manufacturing steps, and no problem is caused in performance when the thicknesses thereof are in the aforementioned range.
  • the intermediate layer contains at least 50 percent by volume and not more than 100 percent by volume of WC since desired thermal conductivity cannot be attained and the layer cannot serve as a thermal divergence layer if the WC content is not more than 50 percent by volume with a rest of the metal binder phase mainly composed of Co and Ni.
  • the thickness of this intermediate layer is set in the range of at least 0.5 ⁇ m and not more than 10 ⁇ m since desired thermal conductivity cannot be attained if the thickness is less than 0.5 ⁇ m while wear resistance is remarkably deteriorated if the thickness exceeds 10 ⁇ m.
  • Each of the outermost and lowermost layers which are necessarily formed for obtaining the most important intermediate layer, must have a thickness of 0.1 ⁇ m, while the same may cause welding with a main component of a workpiece and iron in cutting leading to chipping if the thickness exceeds 10 ⁇ m. It has been proved by a result of study that no influence is exerted on cutting performance if the outermost and lowermost layers are not more than 10 ⁇ m in thickness.
  • the inventive nitrogen-containing sintered hard alloy of the aforementioned structure has a region containing absolutely no or not more than 2 percent by volume of a metal binder phase in its surface part immediately under the exudation layer 1 containing the metal binder phase, which is mainly composed of Ni and Co, and WC, and this region has a thickness of at least 2 ⁇ m and not more than 100 ⁇ m (preferably 2 to 50 ⁇ m) from the portion immediately under the exudation layer 1 toward the interior.
  • the region immediately under the exudation layer 1 has extremely high hardness, whereby both of wear resistance and thermal shock resistance can be compatibly attained.
  • the surface part of the alloy contains not more than 2 percent by volume of the metal binder phase which is mainly composed of Co and Ni since no remarkable improvement of wear resistance is recognized if the metal binder phase is present in a higher ratio.
  • the thickness of the region located immediately under the exudation layer 1 is set in the range of at least 2 ⁇ m and not more than 100 ⁇ m since no improvement of wear resistance is recognized if the thickness of the region is less than 2 ⁇ m while the region is rendered too hard and fragile to deteriorate chipping resistance if the thickness exceeds 100 ⁇ m.
  • the region containing absolutely no or not more than 2 percent by volume of WC located immediately under the exudation layer 1 has a thickness of at least 1 ⁇ m and not more than 500 ⁇ m (preferably 20 to 100 ⁇ m) toward the interior of the alloy.
  • the abundance of WC is preferably gradually increased from the aforementioned region located immediately under the exudation layer 1 toward the interior so that the volume percentage of WC reaches the average WC volume percentage of the overall alloy at a depth within 1 mm (preferably 0.3 to 0.7 mm) from the portion immediately under the exudation layer 1.
  • the Young's modulus of the overall alloy is increased due to the presence of WC, whereby mechanical strength is remarkably improved. Further, both of thermal shock resistance and chipping resistance can be compatibly attained by providing WC only in the interior with no presence on the surface part of the alloy.
  • the thickness of the region, located immediately under the exudation layer 1, containing absolutely no or not more than 2 percent by volume of WC toward the internal direction is set in the range of at least 1 ⁇ m and not more than 500 ⁇ m since wear resistance is deteriorated due to influence by reduction in hardness caused by WC if the thickness is less than 1 ⁇ m while the effect of improving toughness of the alloy itself by WC cannot be attained if the thickness exceeds 500 ⁇ m.
  • the aforementioned structure of the inventive alloy can be obtained by setting a sintering temperature in the range of 1350 to 1700°C in a specified composition and controlling a sintering atmosphere and a cooling rate.
  • the thicknesses of the three layers forming the exudation layer 1 can be adjusted by controlling the sintering temperature and the cooling rate.
  • the volume percentage of WC is measured by the following method: A section of a WC-Co cemented carbide member having a known WC content is lapped to take a SEM photograph of 4800 magnifications. An area occupied by WC in this photograph is calculated by an image analyzer, to draw a calibration curve on the area occupied by WC. As to the inventive alloy, a section of a portion to be observed is lapped and an area occupied by WC is calculated from an SEM photograph of 4800 magnifications by an image analyzer, for obtaining the volume percentage of WC from a calibration curve.
  • the sample 1 had a Ti content of 34 percent by weight in terms of TiCN, a W content of 45 percent by weight in terms of WC, and a Ta and Nb content of 6 percent by weight in terms of TaC + Nb.
  • the atomic ratio N/(C + N) was 0.3.
  • absolutely no WC particles were present in a region of 10 ⁇ m in thickness located immediately under a soft layer, and the abundance of a hard phase containing WC was 15 percent by volume in the interior of 1 mm in depth from the outermost surface.
  • samples 2 to 4 were prepared by conventional methods respectively.
  • the sample 2 was prepared by sintering a stamped compact which was identical to that of the sample 1 under a nitrogen partial pressure of 5 Torr at 1400°C.
  • the sample 3 was prepared by cooling a sintered body which was identical to that of the sample 2 under a CO partial pressure of 200 Torr after sintering.
  • the sample 4 was prepared by cooling a sintered body which was identical to that of the sample 2 under a nitrogen partial pressure of 180 Torr after sintering.
  • the abundances of hard phases containing WC located immediately under soft layers were 10 percent by volume, 15 percent by volume and 5 percent by volume respectively.
  • TaC, NbC, ZrC and VC of 1 to 3 ⁇ m in mean particle size were blended in weight ratios shown in Table 1 to form sintered alloys through steps similar to those for the sample 1, thereby preparing samples 5 to 10 having reduced contents shown in Table 1.
  • Ni, Co, ZrC and VC were omitted from Table 1 since the reduced contents thereof were substantially identical to the blending compositions.
  • Table 2 shows atomic ratios N/(C + N) , thicknesses of layers provided with not more than 1 percent by volume of hard phases containing WC located immediately under soft layers in alloy surface parts, and the abundances of the hard phases containing WC in portions of 1 mm in depth from outermost surfaces.
  • Blending Composition (weight %) Reduced Content (weight %) (TiTaNbW)CN WC TaC NbC ZrC VC Ni Co TiCN WC TaC + NbC 1 2* 3* 45 40 - - - - 7 8 34 45 6 4* 5 30 40 4 4 2 - 5 15 22 45 11 6 60 20 3 - - 2 10 5 44 30 9 7* 80 2 2 - 2 - 7 7 58 15 11 8* 89 - - - - - 5 6 65 14 10 9* 50 40 - 2 - - 4 4 37 48 7 10* 45 25 2 - 2 - 13 13 3 32 7 Note) Asterisked numerals indicate comparative samples, and underlined numeric values are out of the inventive ranges.
  • the samples 1, 5 and 6 having compositions etc. satisfying the conditions according to the first or second aspect of the present invention are superior in wear resistance, toughness and thermal shock resistance to the samples 2 to 4 and 7 to 10 having compositions etc. which are out of the inventive conditions.
  • Raw powder materials shown in Table 5 were blended and mixed/crushed to attain respective reduced contents, thereby forming samples 11 to 23.
  • Each TiCN powder material had a mean particle size of 2 ⁇ m and an atomic ratio C/N of 5/5, while the remaining powder materials were 1 to 3 ⁇ m in mean particle size.
  • Table 5 shows the amounts of blending of these solid solution raw powder materials in terms of single compounds.
  • Blending compositions of the respective samples were omitted from Table 5 since the same were substantially identical to the reduced contents.
  • Table 5 Sample No. Reduced Content (wt.%) TiCN TiC TiN WC Mo2C TaC NbC ZrC HfC Ni Co 11 45 - - 35 5 - - - - 5 10 12 40 - - 30 5 4 2 2 2 5 10 13 - 15 21 44 - - - - - 10 10 14 - 10 16 44 - - 7 3 - 10 10 15 - 23 12 50 - - - - - 8 7 16 - 10 25 50 - - - - - 8 7 17 - 26 17 37 3 3 - - - 6 8 18* 55 - - 25 - 4 - - - 8 8 19* 18 - - 72 - - - - - 5 5 20* - 25 10 50 - - - - - 8 7 21* - 7 28 50 - - -
  • samples 11 to 23 were heated in a vacuum of 10 ⁇ 2 Torr at 3°C/min., degassed at 1200°C for 15 minutes, thereafter sintered under a nitrogen gas partial pressure of 15 to 40 Torr at 1450°C for 1 hour, thereafter control-cooled in a vacuum to 1200°C at 3°C/min., and thereafter nitrogen-quenched.
  • samples 11A to 11C and 12A to 12C were formed after sintering under the same conditions, under various cooling conditions.
  • the samples 11A and 12A were cooled under a CO partial pressure of 150 Torr after sintering under the same conditions as the samples 11 and 12 respectively, the samples 11B and 12B were cooled under a nitrogen partial pressure of 200 Torr, and the samples 11C and 12C were heated to 1530°C, thereafter sintered for 1.5 hours, and thereafter control-cooled.
  • Table 6 shows atomic ratios N/(C + N), thicknesses of regions provided with not more than 1 percent by volume of hard phases containing WC located immediately under soft layers in alloy surface parts, and the abundances of the hard phases containing WC in portions of 1 mm in depth from outermost surfaces as to the samples 11 to 23, 11A to 11C and 12A to 12C.
  • the samples 11, 12 and 13 to 17 having compositions etc. satisfying the conditions according to the first or second aspect of the present invention are superior in wear resistance, toughness and thermal shock resistance to the samples 11A to 11C, 12A to 12C and 18 to 23 having compositions etc. which are out of the inventive conditions.
  • TiCN powder, WC powder, TaC powder, NbC powder, Mo2C powder, VC powder, (Ti 0.5 W 0.3 Ta 0.1 Nb 0.1 )C 0.5 N 0.5 powder, Co powder and Ni powder of 1.5 ⁇ m in mean particle size were blended into a composition shown at A in Table 9, mixed with each other in a wet attriter for 12 hours, thereafter worked into green compacts of a CNMG432 shape under a pressure of 1.5 ton/cm2 , and the green compacts were honed to thereafter prepare sintered hard alloys having structures shown in Tables 11 to 13 under sintering conditions shown in Table 10.
  • the columns "structure from portion immediately under exudation layer toward interior” show composition rates of hard phases and binder phases varied with depths toward interiors of alloys with reference to portions immediately under exudation layers which are set at 0.
  • the WC content is identical to the alloy-average WC volume percentage from the portion immediately under the exudation layer toward the interior, while the binder phase content is 1.8 percent by volume up to 2.5 ⁇ m, gradually increased from 2.5 ⁇ m up to 60 ⁇ m, and identical to the alloy-average binder phase volume percentage in an internal portion beyond 60 ⁇ m.
  • the content of the hard phase forming the rest is expressed in 100 - (alloy-average binder phase volume percentage) - (alloy-average WC volume percentage) in each depth.
  • thermal shock resistance which is superior to that of the prior art can be attained when a sintered hard alloy having a hard phase consisting of TiCN and WC is provided with an exudation layer as specified. It is also understood that wear resistance and thermal shock resistance are improved respectively when binder phase and WC distributions as specified are provided.
  • Raw powder materials which were identical to those of Example 3 were blended into a composition shown at B in Table 9, worked into green compacts by a method identical to that in Example 3, and the green compacts were honed to prepare sintered hard alloys having structures shown in Tables 15 to 17 under the sintering conditions shown in Table 10.
  • Samples b-1 to b-15 were subjected to a thermal shock resistance test and a wear resistance test under conditions (C) and (D) respectively. Table 18 shows the results.
  • thermal shock resistance which is superior to that of the prior art can be attained when a sintered hard alloy having a hard phase consisting of an element belonging to the group 4A, 5A or 6A is provided with an exudation layer as specified. It is also understood that wear resistance and thermal shock resistance are improved respectively when binder phase and WC distributions as specified are provided.
  • Raw powder materials which were identical to those of Example 3 were blended into a composition shown at C in Table 9, worked into green compacts by a method identical to that in Example 3, and the green compacts were honed to prepare sintered hard alloys having structures shown in Tables 19 to 21 under the sintering conditions shown in Table 10.
  • Samples c-1 to c-15 were subjected to a thermal shock resistance test and a wear resistance test under conditions (E) and (F) respectively. Table 22 shows the results.
  • thermal shock resistance which is superior to that of the prior art can be attained when a sintered hard alloy having a solid solution hard phase consisting of an element belonging to the group 4A, 5A or 6A is provided with an exudation layer as specified. It is also understood that wear resistance and thermal shock resistance are improved respectively when binder phase and WC distributions as specified are provided.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Composite Materials (AREA)
  • Powder Metallurgy (AREA)
  • Cutting Tools, Boring Holders, And Turrets (AREA)
EP95107670A 1994-05-19 1995-05-18 Stickstoffenthaltende hartgesinterte Legierung Expired - Lifetime EP0687744B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP97115279A EP0822265B1 (de) 1994-05-19 1995-05-18 Stickstoffenthaltende hartgesinterte Legierung

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JP10558494 1994-05-19
JP10558494A JP3648758B2 (ja) 1994-05-19 1994-05-19 窒素含有焼結硬質合金
JP105584/94 1994-05-19
JP49290/95 1995-02-15
JP04929095A JP3803694B2 (ja) 1995-02-15 1995-02-15 窒素含有焼結硬質合金
JP4929095 1995-02-15

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DE19845376A1 (de) * 1998-07-08 2000-01-13 Widia Gmbh Hartmetall- oder Cermet-Körper
WO2000003047A1 (de) * 1998-07-08 2000-01-20 Widia Gmbh Hartmetall- oder cermet-körper und verfahren zu seiner herstellung
US6110603A (en) * 1998-07-08 2000-08-29 Widia Gmbh Hard-metal or cermet body, especially for use as a cutting insert
EP1548136A1 (de) * 2003-12-15 2005-06-29 Sandvik AB Sinterkarbideinsatz und Method zu dessen Herstellung.
US7427310B2 (en) 2003-12-15 2008-09-23 Sandvik Intellectual Property Ab Cemented carbide tools for mining and construction applications and method of making same
DE19922057B4 (de) * 1999-05-14 2008-11-27 Widia Gmbh Hartmetall- oder Cermet-Körper und Verfahren zu seiner Herstellung
EP2687310A4 (de) * 2011-03-15 2014-09-03 Sumitomo Elec Hardmetal Corp Schneidewerkzeug mit austauschbarer schneideklinge
CN106413954A (zh) * 2014-04-23 2017-02-15 三菱综合材料株式会社 硬质包覆层发挥优异的耐崩刀性的表面包覆切削工具
US20210001405A1 (en) * 2015-11-02 2021-01-07 Hi-Lex Corporation Nitrogen solid solution titanium sintered compact and method for producing same
CN114277299A (zh) * 2021-12-28 2022-04-05 九江金鹭硬质合金有限公司 一种抗焊接开裂的高硬度硬质合金板条及其制备方法

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CN104399988B (zh) * 2014-12-15 2016-06-15 技锋精密刀具（马鞍山）有限公司 一种硬质合金超薄小圆刀片生产系统
KR101863057B1 (ko) * 2015-12-17 2018-06-01 한국야금 주식회사 절삭공구용 인써트

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JPS5487719A (en) * 1977-12-23 1979-07-12 Sumitomo Electric Industries Super hard alloy and method of making same
US4610931A (en) * 1981-03-27 1986-09-09 Kennametal Inc. Preferentially binder enriched cemented carbide bodies and method of manufacture
US4548786A (en) * 1983-04-28 1985-10-22 General Electric Company Coated carbide cutting tool insert
JPH0617531B2 (ja) * 1986-02-20 1994-03-09 日立金属株式会社 強靭性サ−メツト
SE453202B (sv) * 1986-05-12 1988-01-18 Sandvik Ab Sinterkropp for skerande bearbetning
JPS63169356A (ja) * 1987-01-05 1988-07-13 Toshiba Tungaloy Co Ltd 表面調質焼結合金及びその製造方法
JP2684721B2 (ja) * 1988-10-31 1997-12-03 三菱マテリアル株式会社 表面被覆炭化タングステン基超硬合金製切削工具およびその製造法
JPH02131803A (ja) * 1988-11-11 1990-05-21 Mitsubishi Metal Corp 耐欠損性のすぐれた耐摩耗性サーメット製切削工具
JPH0726173B2 (ja) * 1991-02-13 1995-03-22 東芝タンガロイ株式会社 高靭性サーメット及びその製造方法
SE9101590D0 (sv) * 1991-05-24 1991-05-24 Sandvik Ab Sintrad karbonitridlegering med bindefasanrikning
SE505425C2 (sv) * 1992-12-18 1997-08-25 Sandvik Ab Hårdmetall med bindefasanrikad ytzon
EP0635580A4 (de) * 1993-02-05 1996-02-07 Sumitomo Electric Industries Stickstoffenthaltende hartgesinterte legierung.

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000003047A1 (de) * 1998-07-08 2000-01-20 Widia Gmbh Hartmetall- oder cermet-körper und verfahren zu seiner herstellung
US6110603A (en) * 1998-07-08 2000-08-29 Widia Gmbh Hard-metal or cermet body, especially for use as a cutting insert
US6506226B1 (en) 1998-07-08 2003-01-14 Widia Gmbh Hard metal or cermet body and method for producing the same
DE19845376C5 (de) * 1998-07-08 2010-05-20 Widia Gmbh Hartmetall- oder Cermet-Körper
DE19845376B4 (de) * 1998-07-08 2007-03-08 Widia Gmbh Hartmetall- oder Cermet-Körper
DE19845376A1 (de) * 1998-07-08 2000-01-13 Widia Gmbh Hartmetall- oder Cermet-Körper
DE19922057B4 (de) * 1999-05-14 2008-11-27 Widia Gmbh Hartmetall- oder Cermet-Körper und Verfahren zu seiner Herstellung
US7678327B2 (en) 2003-12-15 2010-03-16 Sandvik Intellectual Property Aktiebolag Cemented carbide tools for mining and construction applications and method of making same
US7427310B2 (en) 2003-12-15 2008-09-23 Sandvik Intellectual Property Ab Cemented carbide tools for mining and construction applications and method of making same
EP1548136A1 (de) * 2003-12-15 2005-06-29 Sandvik AB Sinterkarbideinsatz und Method zu dessen Herstellung.
EP2687310A4 (de) * 2011-03-15 2014-09-03 Sumitomo Elec Hardmetal Corp Schneidewerkzeug mit austauschbarer schneideklinge
CN106413954A (zh) * 2014-04-23 2017-02-15 三菱综合材料株式会社 硬质包覆层发挥优异的耐崩刀性的表面包覆切削工具
US10307830B2 (en) 2014-04-23 2019-06-04 Mitsubishi Materials Corporation Surface-coated cutting tool having hard coating layer that exhibits excellent chipping resistance
US20210001405A1 (en) * 2015-11-02 2021-01-07 Hi-Lex Corporation Nitrogen solid solution titanium sintered compact and method for producing same
US11802324B2 (en) * 2015-11-02 2023-10-31 Hi-Lex Corporation Nitrogen solid solution titanium sintered compact and method for producing same
CN114277299A (zh) * 2021-12-28 2022-04-05 九江金鹭硬质合金有限公司 一种抗焊接开裂的高硬度硬质合金板条及其制备方法
CN114277299B (zh) * 2021-12-28 2022-10-04 九江金鹭硬质合金有限公司 一种抗焊接开裂的高硬度硬质合金板条

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Publication number Publication date
EP0687744B1 (de) 1999-11-03
DE69513086D1 (de) 1999-12-09
EP0687744A3 (de) 1996-08-21
KR0180522B1 (ko) 1999-02-18
EP0822265A3 (de) 1998-04-15
KR950032671A (ko) 1995-12-22
EP0822265A2 (de) 1998-02-04
EP0822265B1 (de) 2001-10-17
DE69523342T2 (de) 2002-06-27
DE69513086T2 (de) 2000-07-13
DE69523342D1 (de) 2001-11-22

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