JPH0651875B2 - Aluminum cold forging lubricant - Google Patents

Description

The present invention relates to a lubricant for cold forging of aluminum or aluminum alloy.

BACKGROUND OF THE INVENTION Aluminum or its alloys are widely used in sashes, food and drink cans, home electric appliances such as VTRs, etc. because of their light weight and good appearance quality. Most of the parts built into these products are manufactured by highly productive plastic working. Although the method of plastic working differs depending on the structure and working rate of parts, cold forging, which has many advantages in terms of economy, is becoming the mainstream. In general, aluminum or aluminum alloy parts place a high demand on the surface condition (glossiness), dimensional accuracy, etc., because the appearance is important.
As a lubricant used for cold forging, mineral oil as a base oil, oiliness improver such as fatty acid, fatty acid ester, higher alcohol, extreme pressure agent such as tricresyl phosphite, trilauryl phosphite or graphite, disulfide Processing oil containing a solid lubricant such as molybdenum is used. These lubricating oils have a composition that was considered with emphasis on the surface condition after processing, and can only be applied to machined parts with a small amount of plastic deformation, so-called low machining rate, and have a high surface pressure. When making high parts or processed parts with complicated shapes, the load bearing capacity and lubricity of the lubricant are insufficient, so line marks, cracks, rough skin, seizure, and even deformation on the surface of the processed parts Due to uneven thickness, etc., the application is limited.

In order to improve the seizure resistance, which is one of the important roles of the cold forging lubricant, a method of increasing the amount of oil taken into the friction surface between the die working surface and the material during processing is adopted.

That is, the wettability and adhesion to the material are improved.
As such an example, one or more monooxy or diphosphoric acid ester of polyoxyalkylene alkyl ether or polyoxyalkylene alkyl phenyl ether and one or more saturated or unsaturated fatty acid ester having 12 to 18 carbon atoms or higher alcohol. And one or more kinds of metal soap and a lubricant for processing aluminum, which is blended with mineral oil (Japanese Patent Laid-Open No. Sho 5
4-36303, U.S. Pat. No. 1,087,247) and polyoxyalkylene derivatives, a higher carboxylic acid partial ester of a polyhydric alcohol, a higher alcohol alone or a mixture of both, and a phosphorus compound (Japanese Patent Application Laid-Open No. S60-187200). 5
6-26997). However, when machining with these conventional lubricants, the machining rate is high, and when a complex-shaped part is machined, the state of the machined surface is deteriorated and line marks, cracks, uneven thickness, and seizure occur. On the other hand, there is a method in which a pretreatment such as a chemical conversion film treatment is applied to the surface of the material, and then metallic soap is attached to the surface of the material to process it. In this case, seizure does not occur even in the processing with a high processing rate, but the appearance is deteriorated such as the surface being colored, and finishing by machining is required. In addition, the pre-lubrication treatment in this case requires a complicated process and requires a lot of cost for maintenance and management of the treatment liquid.

[Object of the Invention]

An object of the present invention is to provide a lubricant for cold forging of aluminum and aluminum alloy, which exhibits good lubricity and seizure resistance even in cold forging having a high working rate by only applying to a raw material.

[Outline of Invention]

The lubricant of the present invention is characterized in that a mineral oil, a synthetic oil or a mixed base oil thereof is blended with an organic lubricant having a particle size of 67 to 74 μm or more.

The organic lubricant used in the present invention includes fatty acid lithium,
Metal soap consisting of calcium, zinc, sodium, aluminum or barium salt, such as lithium stearate, lithium 12-hydroxystearate, calcium stearate, zinc stearate, sodium oleate, lithium complex soap, calcium complex soap, aluminum complex Synthetic waxes such as metal soaps such as Sox soap, or fatty acids and N-alkylamines, fatty acids and N, N-dialkylamines (however, the alkyl group of alkylamine has 2 to 18 carbon atoms), for example, N- Hydroxyethyl 12-hydroxy stearyl amide, N, N'-ethylenebisoleylamide, N, N'-ethylenebisricinoylamide, N, N'-ethylenebisoctadecadienylamide, N, N'-ethyl Emissions bisstearylamide, N,
N'-hexamethylenebisricinoylamide, N, N '
-A synthetic wax such as hexamethylene bis 12 hydroxy stearyl amide. These metal soaps or synthetic waxes are powders or micelles dispersed in a lubricating oil, and the compounding amount should be arbitrarily selected according to the shape of the processed parts and the degree of processing, but in normal processing The preferable blending amount is 2 to 15% by weight.

Lubricating oils containing the above metal soaps and synthetic waxes are mineral oils, α-olefin oils, ester oils, polybutene oils,
Synthetic oils such as polyglycol oil, silicate oil, silicone oil, and mixed oils thereof are used. The properties of the lubricating oil can be arbitrarily selected according to the processing conditions and working conditions, but the viscosity at 40 ° C is 5 mm ² / s (cst).
The above is preferable.

The actions of the metallic soap and synthetic wax used in the present invention are described below. That is, the powder of the metallic soap or the synthetic wax dispersed in the lubricating oil or the micelle of the fiber structure is confined between the material surface or the mold surface and the material during processing. The confined metal soap or synthetic wax is sent to the friction surface as the material is deformed, and a deformation film or friction heat forms a lubricating film to prevent seizure. When the amount of the metallic soap or synthetic wax is small, the amount of the metallic soap or synthetic wax trapped is small, so that the lubricating coating formed on the friction surface becomes thin and metal contact occurs. Further, if the amount is too large, no further effect is observed, so the above-mentioned ratio is preferable.

In addition, an antioxidant, an oiliness improver, an extreme pressure agent and the like can be added within a range that does not impair the object of the present invention.

The aluminum and aluminum alloy cold forging lubricant of the present invention can be applied to deep drawing, drawing, wire drawing, rolling and various extrusion processes. Further, the material of the die used for processing is not particularly limited, but a good processed product can be obtained even with an alloy tool steel or a die having a hard treatment on the surface of the alloy tool.

Example of Invention

Examples 1 to 13 Using a mineral oil having a viscosity of 10 mm ² / s (cst) at 40 ° C., a metal soap having a particle size of 63 to 74 μm shown in Table 1 and a synthetic wax were dispersed in 10% by weight of oil. The blended cold forging lubricant of the present invention was obtained. After applying the lubricant for cold forging to the surface of an aluminum alloy (JIS A5056) material, the processing performance, the surface condition after processing, and the like were examined by the forward extrusion processing method and the backward extrusion processing method under the following conditions. The results are shown in Table 1.

The processing conditions and the measurement of the processing performance are as follows.

1. Processing conditions 1.1 Material for front extrusion processing Material: Aluminum alloy (JIS A5056) Dimension: Outer shape 9.9 mm, length 30 mm Surface roughness: max 2.0 μm (2) Material for rear extrusion processing Material: Aluminum alloy (JIS A5056) Dimensions: Outer diameter 19.9 mm, length 20 mm Surface roughness: max 2.0 μm 1.2 Main mold dimensions (1) For forward extrusion Material: Alloy tool steel SKD11 Container diameter: 10 mm Extrusion angle: 120 degrees Drawing diameter: 6mm (Processing rate 64%) (2) For backward extrusion Material: Alloy tool steel SKD11 Container diameter: 20mm Punch diameter: 16mm (SKD11 material) Processing rate: 63.9% 2. Machining performance evaluation method Attach a heater and set the mold temperature to 5
Gradually raise by ~ 20 ℃, and process 10 materials each with lubricant applied at each temperature at a processing speed of 14 mm / s.
The surface condition of the machined surface and the maximum temperature of the mold that can be machined without seizure were measured. The higher this temperature, the better the heat resistance and lubricity of the lubricating coating formed on the surface of the material.

Comparative Example Lubricant Composition Comparative Example 1 Comparative example 2 As is clear from the results in Table 1, it is clear that the cold forging lubricant of the present invention has a good material surface after processing and has excellent processing performance as compared with the comparative example. .

Examples 14 to 25 N-hydroxyethyl 12-hydroxystearyl amide having a particle size of 63 to 74 μm and sodium stearate are blended in the synthetic oil shown in Table 2 in an amount of 10% by weight to obtain a lubricant for cold forging according to the present invention. It was This was processed under the same conditions as in the example, and the surface condition and processing performance after processing were measured. The results are shown in Table 2.

As is clear from the results shown in Table 2, the lubricant for cold forging according to the present invention is excellent in the surface condition after processing and the processing performance.

[Effect of the Invention] As is clear from the above examples, the cold forging lubricant for aluminum and aluminum alloys of the present invention forms a lubricating coating on the friction surface during processing only by applying it to the surface of the material. Since it prevents seizure, it greatly contributes to simplification of processing steps and cost reduction.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication C10N 10:06 20:06 Z 8217-4H 30:06 40:24 A 8217-4H (72) Invention Fumio Nakano 4026 Kuji Town, Hitachi City, Ibaraki Prefecture, Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor, Toshikazu Narahara 4026 Kuji Town, Hitachi City, Ibaraki Prefecture, Hitachi Research Laboratory, Hitachi Ltd. (56) References 60-192795 (JP, A)

Claims (1)

[Claims] 1. A lubricating oil comprising mineral oil and / or synthetic oil,
Metallic soap consisting of lithium, calcium, zinc, sodium, aluminum or barium salt of fatty acid, fatty acid and N-alkylamine, fatty acid and N, N-dialkylamine (however, the alkyl group of alkylamine has 2 to 18 carbon atoms) Particle size selected from synthetic wax consisting of 6
A lubricant for cold forging of aluminum, comprising 2 to 15% by weight of one or more organic lubricants having a size of 3 to 74 μm.