CS242177B1 - A method of producing aluminum bronze powder molded parts - Google Patents

Abstract

The invention relates to a method of manufacturing shaped parts from aluminum bronze, in particular the production of active parts of forming tools for forming stainless steels. The essence of the invention is that from the cast base material, a powder with a grain size of 0.04 to 0.1 mm is prepared by grinding or crushing, which is cold pressed into a semi-finished product or a pressed product with a density of 75 to 80% and subsequently annealed for a long time without the presence of a liquid phase in a protective environment at a temperature of 530 to 570 °C and then forged in a closed die from a temperature of 850 to 950 °C to the final shape with a degree of compaction of 98 to 100%.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for the manufacture of aluminum bronze shaped parts, in particular to the manufacture of active parts of forming tools for forming stainless steels.

SUMMARY OF THE INVENTION It is an object of the present invention to prepare from a cast base material by grinding or crushing a powder having a particle size of 0.04 to 0.1 mm, which is cold pressed into a stock or compact of 75 to 80% density and subsequently annealed in the absence of a liquid phase in a protective coating. at a temperature of 530 to 570 ° C and then forged in a closed die from 850 to 950 ° C, complete the compaction with a degree of compaction of 98 to 100%. 242177 242177

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a method for producing aluminum bronze powder molded parts.

The predominantly medium-weight aluminum bronzes are used for components with good structural performance properties as well as for the production of active tool insert inserts, mainly for the processing of stainless steels. At present, the production of shaped parts made of aluminum bronzes is carried out through a liquid phase, for example, according to AO 235 600, where the products have been obtained materially very well. However, further machining has been shown to result in a deterioration of the flood properties. The disadvantage was also the demanding production of precise molds. The manufacture of molded parts in conjunction with the current production of aluminum bronze powder metallurgy has the advantages of significantly reducing the cost of preparing and further processing the material obtained through the liquid phase and obtaining products with high chemical and structural homogeneity without the presence of voids and pores, with significant improvements mechanical properties. A disadvantage has in turn been the need for further processing or subsequent plastic deformation.

These drawbacks are largely obviated by the manufacturing process of the molded parts according to the invention, which is made from a cast base material by grinding or crushing a powder having a grain size of 0.04 to 0.1 mm, which is cold pressed at 1100 to 1200 MPa for a blank or compacted density of 75 to 80% and subsequently calcined in the absence of a liquid phase in a protective environment for 15 to 20 hours at a temperature of 530 to 570 ° C and then in a closed die at a temperature of 850 to 950 ° C. to a final shape with additions of from 0.2 to 0.5 mm per dimension to a densification density of 98 to 100 ° / o. An advantage of the method of manufacturing the shaped parts according to the invention is the high structural homogeneity, where the material is free of pores and voids. Furthermore, it is possible to obtain complex shapes of parts, respectively. parts of forming tools of better mechanical properties with the possibility of their further heat treatment.

A higher effect is in increasing the productivity of work in connection with the production of components, and this is in the order of magnitude higher than the technological processes used so far. The method leads to high material utilization.

In this way, tensile mandrels were produced for the production of stainless steel tubes, where tool bronze with a chemical composition of 14% Al, 0.5% Si, 0.4% Cr, 0.1% B, 0.1% C, 0.8 % Fe, 0.5% Ti, 0.5% Co and 2% Mn, prepared according to AO 235 600 from the liquid phase, was then crushed and milled in a jet mill with a particle size of 0.04 to 0, 6 mm. After compression of the thus obtained powder at a pressure of 1200 MPa in a hydrostatic medium, a forging stock of 78% density was obtained. The products obtained were further annealed in three stages for 6 to 8 hours in a protective environment at 550 ° C. The required 20 µm diameter and 20 mm height as well as the required compaction were achieved by drop forging from 900 ° C. The results of the investigation confirmed the expected advantageous properties of the component, while the Al-bronze hardness did not change. The resulting hardness was 400 HV.

Claims (1)

PREDMET A method of producing aluminum bronze powder molded parts, especially manufacturing active parts of forming tools for forming stainless steels, characterized in that a powder having a grain size of 0.04 to 0.1 mm is prepared by grinding or crushing from a cast base material. pressurizes at a pressure of 100 to 1200 MPa on a SMALL lottery or compact of density of 75 to 80% and is subsequently calcined in the absence of a liquid phase in a protective environment for 15 to 20 hours at a temperature of 530 to 570 ° C and then at a temperature of at an interval of 850 to 950 ° C, the resulting shape is completed with additions from 0.2 to 0.5 mm per dimension with a degree of glowing and 98 to 100%. '