Study On ZrO₂-Ni Nanocomposite Powder & Materials

Material scientists over the world are having been working earnestly and consciously to seek out materials having both qualities of metal and nonmetal. ZrO2-Ni cermet materials have been widely used in the SOFC and FGM areas.The synthesis of the ZrO2-Ni nanocrystalline composite powder is one of the most important processes in the manufacture of the ZrO2-Ni cermet of excellent capability. In this study we adopt a novel coordination-gel method to prepare ZrO2-Ni nanocrystalline composite powder. Compared to the traditional methods such as coprecipitation,combusting solution synthesis and sol-gel method,coordination-gel method avoids the disadvantages such as bad uniformity of phases' buildup and difficulty of controlling the craftwork. It has many advantages that it is easy to get the raw and processed materials,easy to control buildup of phases and chemical elements,has no pollution,laconic craftwork and high rate of performance to price.By contrast to the general method of preparing ZrO2-Ni cermet that ZrO2 and NiO powder are mixed together,pressed,sintered and reduced,this method is laconic and the ZrO2-Ni cermet is got by preparing nanocrystalline composite powder through immediately reducing reaction,pressing and sintering.In this study,the preparing processes of ZrO2-Ni nanocrystalline composite powder aremixing the nickel salt,zirconium salt and stabilizer,solvent (distilled water) together to prepare the mixing solution according to certain ratio;commingling the mixing solution,coordination solution of carboxylic ammonia,intrusion aid in accordance with certain rate to form sol,drying the sol and turning it into gel,pre-sintering the gel to get the ZrO2-NiO powder andgaining ZrO2-Ni nanocrystalline composite powder by reducing the ZrO2-NiO powder.XRD,X-ray wide-angle diffractometer,BET,SEM,TEM,HRTEM analyses are used to study the ZrO2-Ni nanocrystalline composite powder and ZrO2-Ni cermet. The sintering temperature is determined. Results show that ZrO2-Ni cermet has clear crystalline interface and uniform distribution. Its crystal size is 0.3 P m.Through analyzing the data of specific heat of ZrO2-Ni cermet,it reveals that adulterating cobalt can enhance the wetting quality of Ni and ZrO2.