Quality control of cemented carbide ball mixture preparation process

Cemented carbide ball, commonly known as tungsten steel ball, refers to ball and bead made of tungsten carbide. The production process mainly includes the mixture preparation, forming, sintering, grinding and quality testing. The quality control of each process will affect the final product performance and quality stability. Today we will learn about the quality control of cemented carbide ball mixture preparation process.1. Raw material controlRegarding the raw materials of cemented carbide balls, WC powder purity is generally required to be greater than 99.7%, and harmful impurity elements such as Ca, Si, Al, Na, S and oxygen content are strictly controlled.Impurity elements can affect wettability;If oxygen content is too high, decarburization will occur in the sintering process of tungsten steel ball.The quality control of binder mainly includes composition, structure and particle size, etc. Generally speaking, different grades of cobalt powder with different particle size, that is, fine WC powder with fine cobalt powder, coarse WC powder with coarse cobalt powder.The particle size, particle size distribution, oxygen content and carbon content of raw material powder were kept stable.2. Mixing processMixture processes mainly include wet grinding, drying and granulation.First of all, the hard phase and the bonded phase are mixed by ball milling in the ball mill. After adding the formative agent (usually paraffin or rubber), the wet abrasive slurry is dried by means of vacuum drying and steam drying. Finally, the dried mixture is rubbed and sifted for granulation.Or through the spray granulation method to achieve the mixture drying and granulation of a complete.The common quality defects in the mixing process mainly include fouling and uneven grain size of carbide.The sources of fouling mainly include equipment, tooling, forming agents and personnel, etc., which may lead to the irreducible pores left in the product after sintering, and directly affect the surface quality and properties of cemented carbide balls.Therefore, in the process of production of tungsten steel ball should strictly abide by the operating procedures, operators must wear hats, special gloves, etc.;Workshop equipment should be often wiped to reduce dust residue;The mixing process ensures the uniformity of the mixture, especially the addition of the forming agent. If there are local crystalline particles, it is very easy to volatilize and leave large holes during sintering.The grain size of carbide is mainly determined by the original W powder, WC powder and the particle size and composition of WC in wet grinding, and is also affected by the process conditions such as reduction, carbonization and wet grinding.Coarse carbide is one of the fracture sources of alloy, which directly affects the fracture strength of cemented carbide ball, so it must be strictly controlled from the quality and selection of raw materials.Carbide ballhas high hardness, high wear resistance, good chemical stability and thermal stability, mainly used in the petrochemical industry valve ball, special bearing ball, testing instrument measuring head ball, electric tools and die ball, widely used in precision machinery, aerospace, military defense, petrochemical and other fields.If you want to purchase or customize tungsten steel balls such products, choose a company that controls the quality strictly.Zhuzhou pintejin Cemented Co., Ltd is a manufacturer of cemented carbide raw materials. It has its own customized factory for processing cemented carbide non-standard parts. The material standard is carried out according to the national GB/T18376.3-2001, which is higher than the industry standard.Contact mobile: 0086-180-7331-9589