Harbin Xinhui

Production process of ceramic products
The production process of silicon carbide and boron carbide includes milling, molding, roughing, sintering and finish machining, and finally obtaining the products with requested sizes and shapes. According to the needs of customers, we select the manufacturing method with the best performance, highest quality, lowest price and shortest period for them. Different customers' requirements of size, performance, quantity and other factors result in different production methods of products. General process: First, determine the production method according to the performance, production batch, size and accuracy of the products, and mix the raw material powder with binder and other additives into first slurry and then powder for spray granulation or slurry for casting, injection molding according to different molding methods. And then, according to the requirements of the products, use cool isostatic pressing, or steel mold pressing, or pouring, extrusion or injection molding method to produce powder blanks. After drying, the molded powder blanks need roughing to obtain powder blanks as close as possible to the final required shape in order to reduce subsequent processing, as the processing cost of sintered rough blanks is high. The finished powder blanks should be sintered to obtain high-density products. The aim of sintering is to obtain sintered bodies with fine grains, well distribution and no air holes. Our excellent sintering techniques can have the density of pressureless sintered products reach over 98% of theoretical density and the density of liquid-phase sintered products reach 100% theoretical density, laying a solid foundation for the application of bulletproof laminates and high wear-resistant products. The last step is machining. Use the methods of cutting, grinding or polishing according to the technical requirements of products to ensure the achievement of size accuracy, shape and position accuracy, and surface quality required by customers.
4.1 Milling
Each process during ceramic production is key process to ensure high quality and milling is the first step. First raw material powder meeting the requirements of molding techniques must be used, and then mixing process must ensure uniform mixture. Thirdly, milled powder must meet the requirements of raw material powder by molding techniques to obtain qualified powder blanks. According to the requirements of molding process, use spray granulation

method for steel mold pressing and cool isostatic pressing; and use slurry with proper viscosity for injection molding or casting molding.

4.2 Molding
Molding has a variety of methods determined in accordance with the requirements of the production process. For large batches the best molding method is steel-mold cool pressing molding because of its low production cost and high efficiency. For parts with more complex shapes, injection molding or casting molding can be selected according to specific circumstances. The need of degreasing process causes longer processing time so that sometimes it is difficult to guarantee the production time limit. For large parts such as long rods and large plates, cool isostatic pressing method must be used.
4.3 Sintering
Sintering is an important process to obtain high-quality blanks with the aim of obtaining sintered bodies with fine grains and approach or achievement of theoretical density as quality control targets. Common sintering methods are hot pressing, pressureless sintering or reaction sintering. hot pressing has the best performance while high cost and low efficiency, and only simple-shaped products can be produced with this method. Pressureless sintering is suitable for mass production with low cost and accurate technology control. However, both silicon carbide and boron carbide are difficult for sintering and the adopted sintering temperature is higher than hot pressing. Reaction sintering….
4.4 Machining
Machining needs to be done in order to obtain parts with required shape, size and precision. Cutting is the most effective processing method for silicon carbide and boron carbide ceramic parts. Usually surface grinder is used to obtain the required height and flatness, meanwhile grinding wheels with appropriate particle size should also be adopted to obtain the required surface roughness. The inner bore is the weak link of ceramic part processing. Low line speed and poor processing efficiency of grinding wheels can hardly guarantee the surface quality. High-speed motorized spindle numerical control grinder can achieve good processing quality and efficiency. Cylindrical grinding is mainly to ensure form and position tolerances and surface quality. High-quality grinding wheels and proper cutting parameters are crucial. To obtain high-quality surface, grinding and polishing are very effective.

About Us

TEL：0451-84368085
0451-84368082
0451-82296796
Fax：0451-84368083
Addr：No.18 Donghu Street, Daoli District, Harbin
Zip code：150090