Component Analysis of Metal Matrix of Powder Metallurgy Fric

The advent of powder metallurgy friction materials has been around for nearly a hundred years, especially in recent years. The powder metallurgy process can well match the different properties of metal and non-metal components to one material, and has gradually replaced the tendency of organic materials to bond polymer materials. The powder metallurgy friction material generally consists of three parts: a component constituting the matrix metal skeleton, a lubricating component and a friction component. It is a pseudoalloy containing various components of metals and non-metals.


The matrix component is commonly used for copper, iron, molybdenum disulfide, nickel, titanium, chromium, molybdenum, tungsten, phosphorus, tin, aluminum, zinc, and the like. The base component consists of two parts: the basic component and the auxiliary component. The basic component accounts for the largest proportion of the components. In the iron base, the basic component is iron. In a copper base, the basic component is copper. The auxiliary component forms an alloy with the basic component to improve the performance of the basic component or to impart some desired performance to the basic component. The auxiliary component has molybdenum disulfide, nickel, chromium, molybdenum, copper and phosphorus in the iron-based material. Among the copper bases are mainly tin, aluminum, zinc and phosphorus.
The properties and process characteristics of powder metallurgy friction materials depend to a large extent on the chemical composition, structure and physical and mechanical properties of the matrix components. The matrix component ensures the material's load carrying capacity, thermal stability, wear resistance, and the ability to retain friction and lubricant particles during high temperature operation. Generally, in the powder metallurgy friction material, the matrix component accounts for 50% to 70% of the iron-based material, and accounts for 60% to 90% of the copper-based material.


In recent years, the development of iron-based powder metallurgy friction materials has been rapid, mainly because it saves non-ferrous metals, exhibits superior friction performance under high temperature and high load, has high mechanical strength, and can withstand relatively large pressures, so it is applied in many field. However, since iron has a strong affinity with the dual, which is beneficial to the development of the bonding process, it is necessary to add a large amount of other elements to alloy the iron to reduce the plasticity of the iron, and to increase its strength, yield limit and hardness to overcome the Disadvantages, but at the same time increase the cost and processing complexity. Nickel, chromium and molybdenum are added to the matrix component of the iron-based material, and the main purpose is to improve the mechanical-physical properties and heat and corrosion resistance of the material. The addition of phosphorus can increase the strength of the material and improve the wear resistance. The addition of molybdenum disulfide improves the mechanical and tribological properties of the material. The addition of copper improves the thermal conductivity of the material and contributes to the strength of the material.
Copper-based powder metallurgy friction materials have good process performance, stable friction coefficient, good anti-adhesion, good stuck performance, fast heat conduction, etc. They are used in medium and high speed braking. For example, high-speed brake pads are basically copper-based materials. In addition, working under wet conditions, it also has high wear resistance, so the powder metallurgy friction materials working in oil are basically copper-based materials. Among the copper-based powder metallurgy friction materials, tin, zinc and aluminum are added, which can form a solid solution with the copper matrix, thereby improving the mechanical physical properties and friction properties of the material, and also has great advantages against corrosion resistance.