Technical Questions and Answers in Powder Metallurgy Industry

What powder metallurgy?

Powder metallurgy (PM) is a technology for making metal powder or using metal powder (or mixture of metal powder and non-metal powder) as raw material, forming and sintering, and manufacturing metal materials, composite materials and various types of products. In order to improve the bonding resistance and wear resistance of powder metallurgical materials, a certain amount of solid lubricant is usually added. Graphite and molybdenum disulfide are layered crystalline structures and have been widely used as lubricants in powder metallurgical materials.

Application fields of powder metallurgy products

Powder metallurgy related enterprises are mainly suitable for automobile industry, equipment manufacturing industry, metal industry, aerospace, military industry, instrumentation, hardware tools, electronic appliances and other fields of spare parts production and research, related raw materials, accessories production, all kinds of powder preparation equipment, sintering equipment manufacturing. Products include bearings, gears, carbide cutters, dies, friction products and so on.

Molybdenum disulfide is usually added to powder metallurgical products such as brake pads, valve ducts, bearings, bearing bushes, friction blocks and carbon brushes to increase wear resistance and prolong service life of products.

What is iron base? What is iron-based friction material?

Iron-based means that the composition of materials is based on iron.

Iron-based friction material, as its name implies, refers to the friction material made by powder metallurgy process and chip sintering with iron powder as the matrix, adding appropriate friction and lubrication components. Molybdenum disulfide as a lubricating component is widely used in iron-based powder metallurgy aviation friction materials. However, the different content of molybdenum disulfide will directly affect the properties of iron-based friction materials.

Brake pads

Brake pads are also called brake skins. The types of automobile brake pads are: brake pads for disc brakes; brake shoes for drum brakes.

Common components and structures of disc brake pads include: binder, reinforcing fiber, friction performance regulator, filler, etc. Among them, the addition of friction modifier mainly regulates the thermal stability and working stability of materials, which can be divided into two categories: (1) friction reducing materials: Mohr hardness is generally less than 2, and its addition can improve the friction resistance of materials, reduce noise and reduce friction coefficient. These materials mainly include graphite, molybdenum disulfide, lead, copper and so on. (2) Friction material: Mohr hardness is generally greater than 4, its addition can increase the friction coefficient of the material. Most inorganic fillers and some metals and their oxides belong to this category.

Composition of P/M Friction Materials

Powder metallurgy friction material is a kind of pseudo-alloy with metal and non-metal components. To some extent, these components are classified into three categories:

(1) Metal alloys are the components that form metal matrix and promote the formation of certain physical and mechanical properties.

(2) Adjusting the component of bonding Chengdu, also known as solid lubricant, is used to reduce the friction heat of the friction surface in order to avoid high temperature and reduce wear. Graphite, molybdenum disulfide and sulphides of copper, zinc and barium belong to this kind of component.

(3) Components that regulate the magnitude of mutual mechanical interaction usually become friction agents.