阅读说明：本技术 金属粉末及利用金属粉末加工高性能金属零部件的方法 (Metal powder and method for processing high-performance metal parts by using metal powder ) 是由 周文修 于 2020-07-26 设计创作，主要内容包括：本发明公开了一种金属粉末及利用金属粉末加工高性能金属零部件的方法,本发明的金属粉末由以下重量百分比含量的原料组成：电解铜粉3.1-3.4％、镍粉0.08-0.19％、钼粉0.05-0.15％、钴粉0.05-0.15％、磷铁粉0.3-0.5％、铁铬合金粉1.2-1.4％、硫化锰粉0.5—0.8％、石墨粉0.3-0.6％、蜡粉0.2—0.3％、余量为雾化纯铁粉。本发明提供的金属粉末配方是依据压坯在烧结各阶段的致密化变化和相变机理经过反复试验、检验而获得。另外,通过本发明的粉末冶金方法可以生产出符合要求的高性能金属零部件。(The invention discloses metal powder and a method for processing high-performance metal parts by utilizing the metal powder, wherein the metal powder comprises the following raw materials in percentage by weight: 3.1 to 3.4 percent of electrolytic copper powder, 0.08 to 0.19 percent of nickel powder, 0.05 to 0.15 percent of molybdenum powder, 0.05 to 0.15 percent of cobalt powder, 0.3 to 0.5 percent of ferrophosphorus powder, 1.2 to 1.4 percent of iron-chromium alloy powder, 0.5 to 0.8 percent of manganese sulfide powder, 0.3 to 0.6 percent of graphite powder, 0.2 to 0.3 percent of wax powder and the balance of atomized pure iron powder. The metal powder formula provided by the invention is obtained by repeated tests and inspections according to the densification change and the phase change mechanism of the pressed compact in each sintering stage. In addition, the powder metallurgy method can produce high-performance metal parts meeting the requirements.)

1. The metal powder formula is characterized by comprising the following raw materials in percentage by weight: 3.1 to 3.4 percent of electrolytic copper powder, 0.08 to 0.19 percent of nickel powder, 0.05 to 0.15 percent of molybdenum powder, 0.05 to 0.15 percent of cobalt powder, 0.3 to 0.5 percent of ferrophosphorus powder, 1.2 to 1.4 percent of iron-chromium alloy powder, 0.5 to 0.8 percent of manganese sulfide powder, 0.3 to 0.6 percent of graphite powder, 0.2 to 0.3 percent of wax powder and the balance of atomized pure iron powder.

2. A method of processing a high performance metal part using the metal powder set forth in claim 1, comprising the steps of:

s1) mixing raw materials: weighing corresponding raw materials according to corresponding content in the metal powder formula, putting the raw materials into a stirrer, pumping a stirring cavity of the stirrer into negative pressure, and starting the stirrer to fully stir in a negative pressure environment for 1.5-2.5 hours;

s2) forming: feeding the mixed formula powder into a press, and compacting by the press according to processing parameters to form a green body, wherein the density of the green body is kept at 6.4 +/-0.05 g/cm³；

S3) sintering: putting the green body into a hearth for sintering process, and feeding protective gas into the hearth in the sintering process, wherein the protective gas is nitrogen and decomposed ammonia, and the nitrogen flow is 10-15Nm³The flow rate of the decomposed ammonia is 6-7Nm³The sintering process comprises a preheating section and a sintering section, wherein the preheating section is divided into a pre-1 area, a pre-2 area and a pre-3 areaThe temperature of each time section is respectively as follows: the pre-1 area is 480 +/-5 ℃, the pre-2 area is 660 +/-5 ℃, the pre-3 area is 780 +/-5 ℃, and the total sintering time is 2.5-3 hours, wherein the pre-1 area is a quick dewaxing area; the sintering section is divided into four sections of 1-burning zone, 2-burning zone, 3-burning zone and 4-burning zone before and after the sintering section, and the temperature of each section is respectively as follows: the sintering time is 3.5-4h in total in a 1-burning zone 1075 +/-5 ℃, a 2-burning zone 1110 +/-5 ℃, a 3-burning zone 1120 +/-5 ℃, a 4-burning zone 1120 +/-5 ℃;

s4) grinding, shaping and counting the sintered semi-finished products in sequence to form finished products.

3. The method as claimed in claim 2, wherein before the mixing of the raw materials in step 1, a pre-treatment step is further included, in which the atomized pure iron powder is heated at 300 ℃ under negative pressure for 15-20 minutes, and when the temperature of the heated atomized pure iron powder is reduced to 50-60 ℃, the atomized pure iron powder and other raw materials are mixed together in the mixer.

Technical Field

The invention relates to the technical field of powder metallurgy, in particular to a method for processing a high-performance metal part by utilizing metal powder.

Background

Powder metallurgy mainly uses metal powder as a raw material, and the metal powder is changed into a metal part required by people through a certain processing technology. The powder metallurgy process has the advantages that special materials can be processed, refractory metals, compounds, pseudo alloys and porous materials can be manufactured, and in addition, the powder metallurgy process saves metals and reduces the cost. Since powder metallurgy can be pressed into final size compacts, no further machining is required.

The powder metallurgy process has the defects that the strength and the toughness of the powder metallurgy product are poor. Since the pores in the compact formed by powder compaction cannot be completely eliminated, the strength and toughness of the product made by powder metallurgy are inferior to those of castings and forgings with corresponding components, and thus the product made by powder metallurgy cannot be made into large-scale products.

In the past, precision-grade guides, pistons, compression valve bodies, automobile shock absorbers and other parts have severe working environments and have high requirements on the precision, strength, hardness and other properties of the parts and need to be produced in a casting mode, but the parts produced in the production mode have high cost and serious raw material waste.

Therefore, it is an urgent technical problem to improve the metal powder formulation and process to produce high-performance metal parts capable of adapting to the harsh working environment.

Disclosure of Invention

In view of the above, one of the objectives of the present invention is to provide a metal powder formulation, by which a high-performance metal part meeting the requirements can be produced.

In order to achieve the purpose, the invention adopts the technical scheme that:

the invention relates to a metal powder formula which comprises the following raw materials in percentage by weight: 3.1 to 3.4 percent of electrolytic copper powder, 0.08 to 0.19 percent of nickel powder, 0.05 to 0.15 percent of molybdenum powder, 0.05 to 0.15 percent of cobalt powder, 0.3 to 0.5 percent of ferrophosphorus powder, 1.2 to 1.4 percent of iron-chromium alloy powder, 0.5 to 0.8 percent of manganese sulfide powder, 0.3 to 0.6 percent of graphite powder, 0.2 to 0.3 percent of wax powder and the balance of atomized pure iron powder.

The proportion of the electrolytic copper powder is improved, and the ferro-phosphorus powder and the ferro-chromium alloy powder are added, so that the volume shrinkage rate of a product sintered by the metal powder is lowest, and the mechanical property is ensured by combining proper subsequent treatment, thereby improving the size control precision of the sintered body, and ensuring the mechanical property of the product by combining proper subsequent treatment.

The invention also aims to provide a method for processing high-performance metal parts by using metal powder, and the high-performance metal parts meeting the requirements can be produced by the method.

In order to achieve the purpose, the invention adopts the technical scheme that:

the method for processing the high-performance metal parts by using the metal powder comprises the following steps:

s1) mixing raw materials: weighing corresponding raw materials according to corresponding content in the metal powder formula, putting the raw materials into a stirrer, pumping a stirring cavity of the stirrer into negative pressure, and starting the stirrer to fully stir in a negative pressure environment for 1.5-2.5 hours;

s2) forming: feeding the mixed formula powder into a press, and compacting by the press according to processing parameters to form a green body, wherein the density of the green body is kept at 6.4 +/-0.05 g/cm³；

S3) sintering: putting the green body into a hearth for sintering process, and feeding protective gas into the hearth in the sintering process, wherein the protective gas is nitrogen and decomposed ammonia, and the nitrogen flow is 10-15Nm³The flow rate of the decomposed ammonia is 6-7Nm³The sintering process comprises a preheating section and a sintering section, the preheating section is divided into three sections of a pre-1 section, a pre-2 section and a pre-3 section in front and back, and the temperature of each section is as follows: pre-1 area 480 + -5 deg.C, pre-2 area 660 + -5 deg.C, pre-3 area 780 + -5 deg.C, and sintering time 2.5-3 hr; the sintering section is divided into four sections of 1-burning zone, 2-burning zone, 3-burning zone and 4-burning zone before and after the sintering section, and the temperature of each section is respectively as follows: the sintering time is 3.5-4h in total in a 1-burning zone 1075 +/-5 ℃, a 2-burning zone 1110 +/-5 ℃, a 3-burning zone 1120 +/-5 ℃, a 4-burning zone 1120 +/-5 ℃;

s4) grinding, shaping and counting the sintered semi-finished products in sequence to form finished products.

Preferably, before the raw materials are mixed in the step 1, a material pretreatment step is further included, wherein the atomized pure iron powder is subjected to heating treatment at the temperature of 250-300 ℃ in a negative pressure environment for 15-20 minutes, and when the temperature of the heated atomized pure iron powder is reduced to 50-60 ℃, the atomized pure iron powder and other raw materials are placed into a stirrer together for mixing.

The invention has the beneficial effects that:

1. the metal powder formula provided by the invention is obtained by repeated tests and inspections according to the densification change and the phase change mechanism of a pressed compact at each sintering stage, namely, the volume shrinkage caused by the formation and growth of a sintering neck and the volume expansion rule caused by the formation of a liquid phase (copper phase) are explored, the proportion of electrolytic copper in the formula is increased by utilizing the mutual compensation of the volume shrinkage and the volume expansion rule, and meanwhile, ferrophosphorus powder, ferrochromium alloy powder and the like are added for fine adjustment, so that the size control precision of a sintered body is improved, the mechanical property of a product is ensured by combining proper subsequent treatment, and the full-size change of the product can be controlled within 0.005 mm.

2. The method for processing the high-performance metal part by using the metal powder can produce the high-performance metal part meeting the requirement.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to specific embodiments.