Cobalt powder is prepared by steps of acid leaching, precipitation, calcination, reduction and so on. The WC powder is prepared by smelting, calcining, reducing, carbonizing. WC-Co composite powder was prepared by ball milling, spray drying and sintering with alcohol as wet milling medium. The method has the disadvantages of long process flow, uneven distribution of components, uneven grain growth, large fluctuation of product performance, difficult control of quality, low production efficiency and high manufacturing cost. Therefore, many experts and scholars have developed a new method of preparation of WC-Co composite powder, including mechanical alloying, plasma, chemical precipitation, oxidation - reduction, sol - gel, in situ carburizing, in situ reaction method, direct carbonation method.
Violet Tungsten Oxide Producing WC-Co Composite Powder
Raw material: Violet tungsten oxide, cobalt acetate, organic carbon(carbon content >=40%, soluble in water) and ultra-pure carbon black spray drying tower, high temperature molybdenum continuous carbonization furnace, tilting rolling ball mill.
(1) WC-6% Co as the basic composition, calculating raw materials ingredients amount, violet tungsten oxide, cobalt acetate, organic carbon and ultra-pure carbon black ingredients. Weighing with adding the proper amount of pure water, tilting rolling ball mill, wet mixing 12h to form a complex salt slurry, then followed by thorough stirring.
(2) Spray dry in the spray dry tower, inlet temperature is 230 ℃, outlet air temperature is 125 ℃, feed rate is 60 ml / min and centrifugal speed is 12 000 r / min.
(3) WC-Co composite powder was prepared by loading the powder (200g) into a high-temperature molybdenum wire furnace, introducing hydrogen, calcining temperature is 950 ℃ and calcining time is 30 min.