高 Cr-Fe 合金プラズマ溶射粒子の偏平挙動とNAS 電池用 Al 円筒容器内壁面への皮膜の密着性に及ぼす予熱温度の影響

抄録

  In order to improve the adhesion of 75 mass% Cr-Fe alloy plasma spray coatings, which provide sulfide corrosion resistance for the inner surface of NAS battery high-temperature type Al cylinders, the Al substrate temperature and the flattering behavior of the plasma spray particles were studied. Also, experiments were conducted to study how changes in the preheating temperature of the Al cylinder affected the spray coating's adhesion. The splat morphology of the spray particles changed significantly in relation to the preheating temperature of the Al substrate, from splash shaped to disk shaped as the preheating temperature increased. It was especially evident that the splat morphology of the particles changed sharply at over 433 K, forming disk shaped with excellent adhesion splats to the substrate. In addition, as the preheating temperature was increased, fewer coating defects such as blisters and peeling were seen on the spray coating. A good correlation was found between the flatness of the spray particles and the adhesion of the coating formed by changing the preheating temperature of the Al cylinder. When the preheating temperature was set at over 433 K, coating with good adhesion were formed. It was therefore shown that by studying the flattening behavior of the plasma spray particles, could be found an effective method for improving the adhesion of plasma spray coating.