Iron-based alloy premix for metal injection forming

Abstract

The invention discloses an iron-based alloy premix for metal injection forming. The iron-based alloy premix is obtained by preparing iron-based alloy powder composed of the following ingredients in percentage by weight: 0.2-0.5% of carbon, 1.5-2.5% of nickel, 1-2% of copper, 0.2-0.8% of molybdenum, 0.2-0.8% of chromium and the balance of iron at first; and then carrying out surface treatment on the iron-based alloy powder, and finally mixing with an adhesive, extruding and granulating, and crushing. The iron-based alloy premix disclosed by the invention can be directly used for injection forming without the need of mixing processing treatment with the adhesive during use, and convenient to use; the processed product is uniform in ingredients, uniform and segregation-free in organization, stable in dimensions, not liable to deform, and excellent in mechanical property.

Description

technical field [0001] The invention relates to the technical field of powder metallurgy, in particular to an iron-based alloy premix for metal injection molding. Background technique [0002] At present, the powder metallurgy industry has higher and higher performance requirements for metal injection molding iron-based products. An important way to solve the problem is to improve the performance of the product by adding new alloying elements to the raw material powder. The usual alloying elements are carbon, nickel, Copper, chromium, molybdenum, etc. At present, the raw materials of metal injection molding iron-based products are carbonyl iron powder and carbonyl nickel powder. Although the carbonyl method can produce metal powders with a particle size below 10 microns, it cannot form powders with multiple alloying elements. , the vast majority of product manufacturers often use iron powder, nickel powder, copper powder and other powders mixed together, so that the mixed po...

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Problems solved by technology

[0002] At present, the powder metallurgy industry has higher and higher performance requirements for metal injection molding iron-based products. An important way to solve the problem is to improve the performance of the product by adding new alloying elements to the raw material powder. The usual alloying elements are carbon, nickel, Copper, chromium, molybdenum, etc. At present, the raw materials of metal injection molding iron-based products are carbonyl iron powder and carbonyl nickel powder. Although the carbonyl method can produce metal powders with a particle size below 10 microns, it cannot form powders with multiple alloying elements. , the vast majority of product manufacturers often use iron powder, nickel powder, copper powder and other powders mixed together, so that the mixed powder cannot fully diffuse the alloy elements at the subsequent sintering temperature, forming a so-called "pseudo-alloy" , structure segregation, uneven composition, product performance is difficult to meet the requirements, and the injection molding powder produced by the carbonyl method is generally below 10 microns, and the particle size distribution is narrow, D10 is between 1 and 3 microns, and D50 is between 2 and 5 microns. D90 is between 4 and 7 microns, so powders with particle size distribution also have great disadvantages. If the powder particle size is too fine, the injection billet cannot form a good skeleton support in the process of solvent degreasing and thermal degreasing, so the green body after degreasing Easy to deform, and the narrow particle size distribution leads to low tap density of the powder, an increase in the required binder ratio, large dimensional deformation of the product after sintering, and low yield

[0003] The existing iron-based alloy powder needs to be mixed and processed with a binder before it can be used for injection molding, which is inconvenient to use and increases the processing steps and required equipment. In addition, due to the particle size of the iron-based alloy powder It is fine, easy to agglomerate, and mixed with molten binder unevenly, resulting in sintered product structure segregation, uneven composition, easy deformation, and poor product performance

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