| 摘要 |
<p>PURPOSE:To obtain a heat-treated plate for powder metallurgy which is strong to abrasion, has good melt stickability to sintered metals and is inexpensive by coating the surfaces of carbon or graphite with composite oxide of ZrO2 and metallic oxide having spinel structure by melt spraying. CONSTITUTION:After a carbon or graphite plate is dried at about 250-350 deg.C, powders of ZrO2 and metallic oxide having spinel structure such as MgAl2O4 are mixed and the powder mixture is melt-sprayed and coated on the surface of said plate by a flame melt spraying method using gaseous oxygen-acetylene or a melt spraying method using plasma, and the melt-sprayed film is subjected to a stabilizing treatment if necessary, whereby the heat-treated plate is obtained. If the film thickness of the coating layer is <=10mu, there is no effect of the coating material and if >=1,000mu, the joining strength in insufficient. The most suitable amts. of ZrO2 and the oxide of spinel structure is 1/5-5/1 by weight. If <=20wt% Y2O3 or CaO is added to the above-mentioned composite oxide, the coating layer having much stabler strength is obtained.</p> |
