Research On The Atomized Jet Cooling Influencing The Microstructure And Property Of High-Temperature Alloy

Ni-based high-temperature alloy (GH4169) are widely applied on space,aeronautics,energy and chemical field, which is a kind of indispensable material in the national defense and economic construction. Ni-based alloy is difficult-to-cut, and it has characters of big cutting force,serious work hardening,high cutting temperature and heavy heat in the cutting process, which will cause cutting-tool wear,deformation,heating and deformation of the sample surface and the changing of the structure, all of which influence property of the material. So it is very important to seek a green cooling manner which will use new technology and improve production environment. The conventional method is usually used to the excellent cutting fluid with the agent for sulfur, chlorine and phosphor element, however, the reactant and excrement will pollute the environment and harm to operator. Cryogenic pneumatic mist jet cooling includes cryogenic gas-liquid two phrase flow and full vaporization to enhance the heat transfer potential of cooling medium and obtain the best cooling effect, so the pneumatic mist jet cooling is a green,no-pollution and high efficiency cooling method.The paper rebuild and improve the experimental system, cooperate with the cooperator and develop new system, including the occurring system of cryogenic pneumatic mist jet impinging cooling, the calefaction system for sample and the collecting system of temperature signal, and get a better accurate and higher sensitivity atomized jet cooling experimental platform.Based on this experimental platform, the paper do experiments of pure cold wind cooling and atomized jet cooling on the Ni-based high temperature alloy,Ti-alloy,red cupper and 45metal. It imitates cutting area temperature of practical manufacture area in cutting and grinding process, and definitely analyzes the relationship of proportion of cooling parameters and the cooling effect. Before the atomized jet cooling, we do pure cold wind cooling experiment on the four kind of material to get the perfect cold wind temperature of each material. Then we do atomized jet cooling experiment to each material with different water flow at each perfect cold wind temperature. From this experiment, we can get the perfect water flow of the atomized jet cooling,the cooling effect within each temperature phase.The paper researches the microstructure's changing characters and microhardness' changing rule of GH4169, and get conclusions: (1) the grain size of GH4169 increases with the heating temperature, the higher, and the bigger. When the water flow is bigger, the grain size is smaller after cooling; (2) when it does atomized jet cooling on GH4169, it doesn't get better material's property at all with the big water flow; (3) after atomized jet cooling of GH4169, microhardness will be bigger with the big water flow at 700, microhardness will be smaller when the water flow becomes heavy at 650,550 and 450. When the water flow at a stationary number, the microhardness of material surface at high temperature is bigger than one of low temperature, and the size of which is twice of primary number, with the deepen of the depth, the number reduces, but it is also bigger than primary number; (4) the number of microhardness of GH4169 is bigger than primary number, but it doesn't increase with the increasing water flow.