What are the ways to improve the properties of cemented carbide?

Cemented carbide, as an "industrial tooth", is an indispensable material for modern tools. It is widely used in many fields, such as oil and gas, coal mining, fluid control, engineering machinery, aerospace and so on. So, how to use the limited resources to improve the efficiency? This needs to improve the performance of cemented carbide to improve service life and work efficiency. What we want to share with you today is the way to improve the properties of cemented carbide.

1、Improve the quality of raw materials

1. Improve the purity of raw materials

It is considered that trace elements such as Na, Li, B, F, A1, P and K with content below 200ppm have different effects on reduction and carbonization of N powder and sintering of cemented carbide, and the effects on properties and microstructure of cemented carbide are also worth studying. For example, the alloy with high strength and high impact toughness (such as mining alloy and milling tool) has high requirements, while the continuous cutting tool alloy with small impact load but high machining accuracy has low requirements for raw material purity.

2. Control the particle size and distribution of raw materials

To avoid the appearance of large particles in carbide or cobalt powder raw materials and prevent the formation of coarse carbide grains and cobalt pool during sintering.

At the same time, the particle size and size composition of raw materials are controlled to meet the needs of different products. For example, the cutting tool should use tungsten carbide powder with Fisher particle size less than 2 microns, the wear-resistant tool should use tungsten carbide powder with 2-3 microns, and the mining tool should use tungsten carbide powder with particle size greater than 3 microns.

2、 Improving the microstructure of the alloy

Superfine grain coalescence

The grain size of carbide is less than 1 μ m. It has high hardness and toughness at the same time.

Heterogeneous structural alloys:

Heterogeneous structure alloy is a special kind of cemented carbide which is made by mixing two kinds of mixture with different composition or different particle size. It often has high toughness of coarse grain alloy and high wear resistance of fine grain alloy, or high toughness of high cobalt alloy and high wear resistance of low cobalt alloy.

Super structural alloy

The structure of the alloy is made up of the area of oriented unequal axis WC single crystal flakes connected by those cobalt rich metal veins by special production process. This alloy has outstanding wear resistance and high durability when subjected to repeated compression impact.

Gradient alloy:

The hardness and toughness of the alloy with gradient composition change gradually.

3、 Improvement or selection of new hard phase and binder phase

4、 Surface hardening treatment

Solve the contradiction between wear resistance and toughness, hardness and strength of cemented carbide,

Coating: a layer of tic or tin is deposited on the surface of cemented carbide with good toughness by physical or chemical methods to increase the wear resistance of the alloy,

At present, the coating cemented carbide is developing rapidly in boronizing, nitriding and electric spark deposition.

5、 Adding elements or compounds

6、 Heat treatment of cemented carbide