MIM manufacturing process for weak-magnetism 17-4PH material part

Abstract

The invention discloses an MIM manufacturing process for a weak-magnetism 17-4PH material part. The MIM manufacturing process comprises the following technological steps of: preparing an MIM injection-molded blank; degreasing; sintering; and discharging, wherein in a sintering process, the temperature is increased from the room temperature to 550-650 DEG C at a temperature rise speed of 3-3.5 DEGC / min in negative-pressure sintering; the temperature is increased from 550-650 DEG C to 950-1050 DEG C at a temperature rise speed of 3.8-4.5 DEG C / min in vacuum sintering; the temperature is increased from 950-1050 DEG C to 1270-1300 DEG C at a temperature rise speed of 2-2.5 DEG C / min in partial-pressure sintering; in a first-stage cooling process, the temperature is reduced from 1270-1300 DEGC to 1050-1150 DEG C; in a first-stage cooling temperature-maintaining process, the temperature is maintained for 60 min to 360 min at 1050-1150 DEG C, and nitrogen is charged; in a second-stage cooling process, the temperature is reduced from 1050-1150 DEG C to 550-650 DEG C; and in a third-stage forced cooling process, the temperature is reduced from 550-650 DEG C to 70 DEG C or lower in a forced cooling manner. A product manufactured by the manufacturing method disclosed by the invention is high in dimensional accuracy, high in strength, good in weak magnetism and corrosion resistance, andsmaller than 1.2H / M in magnetic conductivity.

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