MIM manufacturing process of a kind of weak magnetic 17-4ph material parts

Abstract

The invention discloses a MIM manufacturing process of a weak magnetic 17-4PH material part. The process steps include: preparing MIM injection molded blanks, degreasing, sintering and firing. The heating rate is from room temperature to 550-650°C; vacuum sintering is heated at a rate of 3.8-4.5°C / min from 550-650°C to 950-1050°C; partial pressure sintering is heated at a rate of 2-2.5°C / min from 950~1050℃ to heat up to 1270~1300℃; one-stage cooling and cooling will lower the temperature from 1270~1300℃ to 1050~1150℃; Nitrogen; the second-stage cooling lowers the temperature from 1050-1150°C to 550-650°C; the third-stage forced cooling lowers the temperature from 550-650°C to below 70°C. The product prepared by the invention has high dimensional accuracy, high product strength, weak magnetism and good corrosion resistance, and its magnetic permeability is less than 1.2H / m.

Description

technical field [0001] The invention belongs to the technical field of metal injection molding, and in particular relates to a MIM manufacturing process of magnetically weak 17-4PH material parts. Background technique [0002] The MIM process is the metal injection molding process. It is a forming method that injects metal powder and binder plasticized mixture into the model. According to the required ratio, the powder and the binder are mixed into a uniform feed with a MIM special mixer, and after granulation, the mold is injected into a semi-finished product, and then a dense MIM product is formed through catalytic degreasing and high-temperature sintering. The product prepared by the method has the advantages of uniform internal structure, high density, good product surface finish, high dimensional accuracy, stable product quality, and can be mass-produced. [0003] 17-4PH stainless steel material is currently the most widely used stainless steel material in the metal in...

AI Technical Summary

Problems solved by technology

[0003] 17-4PH stainless steel material is currently the most widely used stainless steel material in the metal injection molding process. It is widely used in various industries because of its good comprehensive performance and relatively low price. At present, China is the largest MIM production base in the world, and The vast majority of China's MIM manufacturing is concentrated in the 3C industry. The 3C industry refers to the information appliance industry that combines the three major technology products of computers, communications, and consumer electronics. In the existing technology, 17-4PH materials are used in communications. industry, there will be serious disadvantages, namely magnetism, the magnetism of 17-4PH material will affect signal transmission, for the communication industry, the influence of signal is undoubtedly the biggest defect; and if other non-magnetic materials are used instead, there is no Magnetism must also meet the requirements of MIM processing. The commonly used MIM raw materials are only 316L series and titanium alloy series. Among them, the strength and hardness of 316L materials are very low. Most of the parts in the 3C industry are small and complex in shape, which requires high Precision, due to the low hardness of the 316L material, it is easily deformed during use, which seriously affects the use of the product; although titanium alloy has high strength, it can also meet the non-magnetic requirements, but it is expensive, and it is used in large quantities in the 3C industry. high, no competitive advantage