| 摘要 |
PURPOSE:To form a sprayed deposit having superior film characteristics at a low cost by thermally spraying a powder for thermal spraying of a specific grain diameter prepared by subjecting Cr3C2, Ni, and Cr respectively in the states of fine powders to mixing, granulation, and sintering at a temp. at which no melting occurs to the Cr3C2 grains. CONSTITUTION:Powdered Ni and powdered Cr are mixed with powdered Cr3C2, and the resulting powder mixture is crushed and refined by means of mechanical alloying so as to be formed into a powder of <=10mum primary-grain size. This fine powder is granulated and sintered, by which a powder for thermal spraying having 5-53mum secondary-grain size is formed. This powder for thermal spraying is thermally sprayed on a base material, by which a sprayed deposit in which unmelted Cr3C2 grains are coated with molten Ni and Cr for intergranular joining and the thickness of one layer of Ni and Cr is regulated to <=5mum is formed. By this method, an article having a sprayed deposit which has film characteristics of <=2% porosity and >=700(Hv:200g) hardness can be obtained. The above method is effectively applicable to the strengthening of a seal sliding surface of a side housing made of aluminum alloy for rotary piston engine. |
