CN-122007417-A - Sintering method of alloy ball

Abstract

The invention discloses a sintering method of an alloy ball, which belongs to the technical field of tungsten alloy ball production and comprises the following steps of adhering metal sand to the outer peripheral surface of an undersintered alloy ball, wherein the melting temperature of the metal sand is higher than the re-sintering temperature of the alloy ball, and re-sintering the alloy ball adhered with the metal sand. The metal sand with the melting temperature being higher than the re-sintering temperature is used as an anti-sticking isolation measure, so that the problem that the spheres are mutually adhered to form blocks or clusters due to surface diffusion, liquid phase generation or micro-area melting and other reasons in the high-temperature sintering process can be avoided.

Inventors

• CHANG XI
• REN LINJUN
• MA XIAOGANG
• WANG TAO
• WANG ZHANFENG
• WANG ENFENG

Assignees

• 西安华力装备科技有限公司

Dates

Publication Date

20260512

Application Date

20260401

Claims (10)

1. 1. A method of sintering an alloy sphere, comprising the steps of: and sticking metal sand on the outer peripheral surface of the undersintered alloy ball, wherein the melting temperature of the metal sand is higher than the re-sintering temperature of the alloy ball, and re-sintering the alloy ball stuck with the metal sand.
2. 2. The method of sintering an alloy sphere according to claim 1, comprising the steps of: Loading the undersintered alloy balls into a charging tray; the metal sand is scattered into the material tray, and purified water is scattered to moisten the metal sand; shaking the material tray to stir so that the outer peripheral surface of each alloy ball is adhered with metal sand; And carrying out compound sintering on the alloy balls after stirring.
3. 3. The method of sintering alloy pellets according to claim 2, wherein a tray having a melting temperature higher than the re-sintering temperature is used, and the alloy pellets after stirring are charged into a sintering vessel together with the tray.
4. 4. The method of sintering alloy pellets as set forth in claim 2 further comprising the step of cleaning said tray prior to loading said alloy pellets.
5. 5. The method of sintering alloy spheres according to claim 1, further comprising the step of preparing an under-sintered alloy sphere, purified water, metal sand, and a tray.
6. 6. The method of sintering an alloy sphere according to any one of claims 1 to 5, wherein the alloy sphere is an undersintered polished sphere or a green sphere.
7. 7. The method for sintering alloy spheres according to claim 1, wherein the alloy spheres are tungsten alloy spheres and the metal sand is alumina sand or zirconia sand.
8. 8. The method for sintering alloy balls according to claim 7, wherein the re-sintering temperature is 1380 ℃ to 1450 ℃.
9. 9. The method for sintering alloy balls according to claim 3, wherein the sintering vessel is a molybdenum boat or crucible, and the alloy balls are sintered in a bare manner.
10. 10. The method for sintering alloy balls according to claim 9, wherein when the sintering vessel is a molybdenum boat, the pushing speed of the molybdenum boat is 30 min/boat to 50 min/boat.

Description

Sintering method of alloy ball Technical Field The invention relates to the technical field of tungsten alloy ball production, in particular to a sintering method of an alloy ball. Background Tungsten alloy balls (such as W-Ni-Fe, W-Ni-Cu and other high-density alloy balls) have the characteristics of high density, high strength, excellent armor piercing performance, good corrosion resistance and the like, so that the tungsten alloy balls become one of the main types of critical killing prefabricated fragments of warheads, and the comprehensive performance of the tungsten alloy balls directly relates to the ammunition damage efficiency, so that the guarantee of the uniformity of the structure, the high densification and the stability of the mechanical performance of tungsten alloy ball products is a core requirement in the production process. Currently, in the powder metallurgy preparation process of tungsten alloy balls, the working procedures of compression molding, presintering, sintering and the like are generally adopted. Sintering is a critical step in densification and performance formation and requires long processing times at high temperatures. However, in the actual production process, due to improper control of factors such as sintering temperature, time, atmosphere or charging mode, the phenomenon of 'undersintering' is easy to occur, so that the alloy balls are insufficient in density, more in internal pores and unqualified in hardness or strength, and the military standard cannot be met. For such unqualified products, a secondary high-temperature re-sintering process is generally adopted in the industry to carry out remediation treatment, namely, the undersintered tungsten alloy balls are subjected to high-temperature sintering again so as to reach performance indexes. However, the existing secondary sintering operation mode has obvious technical defects and production bottlenecks, wherein the sticking problem is remarkable, and currently, enterprises mainly rely on manual mode to spread the undersintered spheres in a sintering container (such as a sintering boat or a crucible). Due to the lack of effective anti-sticking isolation measures or special tools, the spheres are extremely easy to adhere to each other and even to a container to form blocks or clusters due to surface diffusion, liquid phase generation or micro-area melting and other reasons in the high-temperature sintering process. The method not only causes the shape damage and the uneven size of the product and is difficult to separate, so that a large amount of waste products are caused or the subsequent treatments such as crushing, polishing and the like are required to be additionally carried out, the qualification rate and the usability of the product are seriously damaged, and the additional production cost and the additional working time are also increased. Disclosure of Invention The invention aims to solve the technical problems and provide a sintering method of alloy balls, which uses metal sand with the melting temperature being higher than the complex sintering temperature as an anti-sticking isolation measure, so that the problems of forming blocks or clusters due to mutual adhesion of balls caused by surface diffusion, liquid phase generation or micro-area melting and the like in the high-temperature sintering process can be avoided. In order to achieve the above purpose, the invention provides the following scheme that the invention discloses a sintering method of alloy balls, which comprises the following steps: and sticking metal sand on the outer peripheral surface of the undersintered alloy ball, wherein the melting temperature of the metal sand is higher than the re-sintering temperature of the alloy ball, and re-sintering the alloy ball stuck with the metal sand. In one embodiment, the method comprises the steps of: Loading the undersintered alloy balls into a charging tray; the metal sand is scattered into the material tray, and purified water is scattered to moisten the metal sand; shaking the material tray to stir so that the outer peripheral surface of each alloy ball is adhered with metal sand; And carrying out compound sintering on the alloy balls after stirring. In one embodiment, a tray having a melting temperature greater than the re-sintering temperature is used, and the alloy pellets after stirring are loaded into a sintering vessel along with the tray. In one embodiment, the method further comprises the step of cleaning the tray prior to loading the alloy pellets. In one embodiment, the method further comprises the step of preparing undersintered alloy balls, purified water, metal sand and a tray. In one embodiment, the alloy sphere is an undersintered polished sphere or a green sphere. In one embodiment, the alloy spheres are tungsten alloy spheres and the metal sand is alumina sand or zirconia sand. In one embodiment, the re-sintering temperature is 1380 ℃ to 1450 ℃. In one embodiment, the sinterin