阅读说明：本技术 一种粉末冶金成型模具加工工艺 (Powder metallurgy forming die processing technology ) 是由 卢杰 张美华 徐志英 于 2019-09-02 设计创作，主要内容包括：本发明涉及成型模具技术领域,尤其涉及一种粉末冶金成型模具加工工艺,包括以下步骤：步骤一,模具粗加工；步骤二,模具成型腔表层电镀镍；步骤三,原料粉末的制备；步骤四,粉末冶金成型；步骤五,粉末冶金成型模具烧制；步骤六,粉末冶金成型模具精加工；步骤七,精密粉末冶金成型模具表面处理；其中,在步骤一中：选用模具钢材料进行常规调质锻造处理,使用车床粗铣模具胚体并制成型腔。该发明中通过在粉末冶金成型模具烧制后再次对粉末冶金成型模具进行压制,可以使得粉末冶金成型模具内部结构更加紧密,提高粉末冶金成型模具结构的强度,在保证同等性能和质量情况下,节约金属,降低生产成本。(The invention relates to the technical field of forming dies, in particular to a processing technology of a powder metallurgy forming die, which comprises the following steps: step one, roughly processing a mould; electroplating nickel on the surface layer of the mold forming cavity; step three, preparing raw material powder; step four, powder metallurgy forming; step five, firing the powder metallurgy forming die; step six, fine machining of the powder metallurgy forming die; seventhly, treating the surface of the precision powder metallurgy forming die; wherein, in the step one: selecting a die steel material to carry out conventional quenching and tempering forging treatment, roughly milling a die blank by using a lathe and manufacturing a die cavity. According to the invention, the powder metallurgy forming die is pressed again after being fired, so that the internal structure of the powder metallurgy forming die is more compact, the structural strength of the powder metallurgy forming die is improved, metal is saved and the production cost is reduced under the condition of ensuring the same performance and quality.)

1. The processing technology of the powder metallurgy forming die is characterized by comprising the following steps of:

step one, roughly processing a mould; electroplating nickel on the surface layer of the mold forming cavity; step three, preparing raw material powder; step four, powder metallurgy forming; step five, firing the powder metallurgy forming die; step six, fine machining of the powder metallurgy forming die; seventhly, treating the surface of the precision powder metallurgy forming die; wherein:

in the first step: selecting a die steel material to carry out conventional quenching and tempering forging treatment, roughly milling a die blank by using a lathe to prepare a die cavity, and carrying out surface roughness Ra and parallelism treatment on the milled die cavity;

in the second step: immersing the mould blank into an alkaline cleaning solution with the pH value of 10-12, soaking for 10-15 min, carrying out electrolytic treatment, wherein the electrolytic current is 2A/dm2, removing oil stains on the surface of the mould blank, washing the mould blank with deionized water, immersing the washed mould blank into an acidic solution with the pH value of 3-4, washing, removing an oxide film on the surface layer of the mould blank, washing the mould blank in the deionized water after acid washing, and putting the washed mould blank into an electroplating solution for electroplating nickel;

in step three: sequentially adding the powder metallurgy raw materials into a stirrer, heating the raw materials by a thermocouple, wherein the heating temperature of the thermocouple is 300-330 ℃, and uniformly mixing and stirring to obtain a mixture for later use;

in step four: adding the mixture into a mold forming cavity by 3-5 times, compacting the mixture by a press machine after adding the mixture once, wherein the pressure is 3-5 MPa during pressing, the compacting is performed for 3-5 seconds until the mold forming cavity is filled with the mixture, and then, pressing the mixture by the press machine to obtain a powder metallurgy forming mold blank for later use;

in the fifth step: immersing a powder metallurgy forming die blank into molten salt, placing the molten salt into an intermediate frequency heating furnace for heating, then placing the powder metallurgy forming die blank into a die forming cavity, pressing the die blank for 10 to 20 seconds at the pressure of 300 to 500MPa by a pressing machine, and keeping the die blank for later use after pressing is finished;

in the sixth step: turning the powder metallurgy forming die by using a lathe, and grinding and polishing to obtain a precise powder metallurgy forming die for later use;

in step seven: cleaning, deoiling and airing a precision powder metallurgy forming die, then placing the precision powder metallurgy forming die into micro-arc oxidation treatment liquid, carrying out micro-arc oxidation treatment on the surface of the precision powder metallurgy forming die, taking out the precision powder metallurgy forming die after the treatment is finished, cleaning and drying the precision powder metallurgy forming die, then placing the precision powder metallurgy forming die into lubricating oil for soaking, draining redundant grease, and then sealing and packaging the precision powder metallurgy forming die.

2. The powder metallurgy forming die processing technology of claim 1, wherein: in the first step, the hardness of the die steel material is up to 30 HRC-36 HRC, the surface roughness Ra of the formed cavity after treatment is 0.4-0.5 mu m, and the parallelism of the formed cavity is 1 mu m-1.5 mu mm.

3. The powder metallurgy forming die processing technology of claim 1, wherein: in the second step, the electroplating solution comprises the following components: 250 g/L-270 g/L of nickel sulfate, 360 g/L-420 g/L of nickel sulfate amino nickel sulfate, 25 g/L-35 g/L of nickel chloride, 52 g/L-56 g/L of boric acid and the balance of water, wherein the pH value of the electroplating solution is 3-4.5.

4. The powder metallurgy forming die processing technology of claim 1, wherein: in the second step, after the nickel electroplating of the mould blank is finished, the mould blank is placed in an oven to be dried, and the temperature in the oven is 250-280 ℃.

5. The powder metallurgy forming die processing technology of claim 1, wherein: and in the fourth step, after the mixture is filled in the mold forming cavity, a pressing machine is used for pressing for 10-20 seconds at the pressure of 300-500 MPa.

6. The powder metallurgy forming die processing technology of claim 1, wherein: in the fifth step, the temperature control process of the heating furnace is as follows: heating the powder metallurgy forming die blank to 400-500 ℃ within 3-5 hours, preserving heat for 2-3 hours, then heating the powder metallurgy forming die blank to 1300-1500 ℃ within 4-6 hours, preserving heat for 1-2 hours, then cooling at the speed of 5-7 ℃/min until the temperature is reduced to 650-700 ℃, and preserving heat for 3-5 hours.

7. The powder metallurgy forming die processing technology of claim 1, wherein: in the seventh step, the temperature of the micro-arc oxidation treatment liquid is 40-50 ℃, and the micro-arc oxidation treatment parameters are as follows: the working voltage of the micro-arc oxidation treatment liquid is 400-450V, and the treatment time is 20-40 minutes.

8. The powder metallurgy forming die processing technology of claim 1, wherein: in the seventh step, the temperature of the lubricating oil is 110-130 ℃, and the soaking time is 4-6 hours.

Technical Field

The invention relates to the technical field of forming dies, in particular to a processing technology of a powder metallurgy forming die.

Background

Powder metallurgy is a process technology for manufacturing metal materials, composite materials and various products by using metal powder as a raw material through forming and sintering, and the powder metallurgy method has a similar place to ceramic production and belongs to a powder sintering technology.

In the preparation process of the existing powder metallurgy forming die, because the surface of the powder metallurgy forming die is not properly treated or the treatment process is not good, the surface hardness and the surface roughness of the powder metallurgy forming die can not meet the requirement of die processing.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a powder metallurgy forming die processing technology, which has the advantages of improving the powder metallurgy forming die and solving the problem that the surface hardness and the surface roughness of the powder metallurgy forming die cannot meet the die processing requirements due to improper surface treatment or poor treatment process of the powder metallurgy forming die.

(II) technical scheme

In order to achieve the technical problem, the invention provides a processing technology of a powder metallurgy forming die, which comprises the following steps:

step one, roughly processing a mould; electroplating nickel on the surface layer of the mold forming cavity; step three, preparing raw material powder; step four, powder metallurgy forming; step five, firing the powder metallurgy forming die; step six, fine machining of the powder metallurgy forming die; seventhly, treating the surface of the precision powder metallurgy forming die; wherein:

in the first step: selecting a die steel material to carry out conventional quenching and tempering forging treatment, roughly milling a die blank by using a lathe to prepare a die cavity, and carrying out surface roughness Ra and parallelism treatment on the milled die cavity;

in the second step: immersing the mould blank into an alkaline cleaning solution with the pH value of 10-12, soaking for 10-15 min, carrying out electrolytic treatment, wherein the electrolytic current is 2A/dm2, removing oil stains on the surface of the mould blank, washing the mould blank with deionized water, immersing the washed mould blank into an acidic solution with the pH value of 3-4, washing, removing an oxide film on the surface layer of the mould blank, washing the mould blank in the deionized water after acid washing, and putting the washed mould blank into an electroplating solution for electroplating nickel;

in step three: sequentially adding the powder metallurgy raw materials into a stirrer, heating the raw materials by a thermocouple, wherein the heating temperature of the thermocouple is 300-330 ℃, and uniformly mixing and stirring to obtain a mixture for later use;

in step four: adding the mixture into a mold forming cavity by 3-5 times, compacting the mixture by a press machine after adding the mixture once, wherein the pressure is 3-5 MPa during pressing, the compacting is performed for 3-5 seconds until the mold forming cavity is filled with the mixture, and then, pressing the mixture by the press machine to obtain a powder metallurgy forming mold blank for later use; in the fifth step: immersing a powder metallurgy forming die blank into molten salt, placing the molten salt into an intermediate frequency heating furnace for heating, then placing the powder metallurgy forming die blank into a die forming cavity, pressing the die blank for 10 to 20 seconds at the pressure of 300 to 500MPa by a pressing machine, and keeping the die blank for later use after pressing is finished;

in the sixth step: turning the powder metallurgy forming die by using a lathe, and grinding and polishing to obtain a precise powder metallurgy forming die for later use;

in step seven: cleaning, deoiling and airing a precision powder metallurgy forming die, then placing the precision powder metallurgy forming die into micro-arc oxidation treatment liquid, carrying out micro-arc oxidation treatment on the surface of the precision powder metallurgy forming die, taking out the precision powder metallurgy forming die after the treatment is finished, cleaning and drying the precision powder metallurgy forming die, then placing the precision powder metallurgy forming die into lubricating oil for soaking, draining redundant grease, and then sealing and packaging the precision powder metallurgy forming die.

Furthermore, in the step one, the hardness of the die steel material is 30 HRC-36 HRC, the surface roughness Ra of the formed cavity after treatment is 0.4-0.5 mu m, and the parallelism of the formed cavity is 1 mu m-1.5 mu m.

Further, in the second step, the electroplating solution comprises the following components: 250 g/L-270 g/L of nickel sulfate, 360 g/L-420 g/L of nickel sulfate amino nickel sulfate, 25 g/L-35 g/L of nickel chloride, 52 g/L-56 g/L of boric acid and the balance of water, wherein the pH value of the electroplating solution is 3-4.5.

Further, in the second step, after the nickel electroplating of the mold blank is completed, the mold blank is placed in an oven and dried, and the temperature in the oven is 250-280 ℃.

Further, in the fourth step, after the mixture is filled in the mold forming cavity, a pressing machine is used for pressing for 10-20 seconds at the pressure of 300-500 MPa.

Further, in the fifth step, the temperature control process of the heating furnace is as follows: heating the powder metallurgy forming die blank to 400-500 ℃ within 3-5 hours, preserving heat for 2-3 hours, then heating the powder metallurgy forming die blank to 1300-1500 ℃ within 4-6 hours, preserving heat for 1-2 hours, then cooling at the speed of 5-7 ℃/min until the temperature is reduced to 650-700 ℃, and preserving heat for 3-5 hours.

Further, in the seventh step, the temperature of the micro-arc oxidation treatment liquid is 40-50 ℃, and the micro-arc oxidation treatment parameters are as follows: the working voltage of the micro-arc oxidation treatment liquid is 400-450V, and the treatment time is 20-40 minutes.

Further, in the seventh step, the temperature of the lubricating oil is 110-130 ℃, and the soaking time is 4-6 hours.

(III) advantageous effects

The invention provides a powder metallurgy forming die processing technology, which has the following beneficial effects:

1. this powder metallurgy forming die processing technology is through suppressing powder metallurgy forming die again after powder metallurgy forming die fires, can make powder metallurgy forming die inner structure inseparabler, improves the intensity of powder metallurgy forming die structure, under guaranteeing equal performance and quality circumstances, practices thrift the metal, reduction in production cost.

2. According to the powder metallurgy forming die machining process, through treatment on the forming cavity, nickel electroplating, fine machining on the powder metallurgy forming die and surface treatment, the flatness of the surface of the powder metallurgy forming die is improved, the oxidation resistance and the wear resistance of the surface of the powder metallurgy forming die are increased, the quality of the powder metallurgy forming die is improved, the process is simple, and the production efficiency is improved.

Drawings

FIG. 1 is a process diagram of the structure of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention will be further described with reference to fig. 1 and the examples.