超音速等离子喷涂的射流特性  

Jet characteristic of supersonic plasma spraying

作　　者：张勇[1] 张雄[1] 郑杰[1] 高琳[1] 林光文 武瑞霞 

机构地区：[1]西安石油大学机械工程学院,西安710000 [2]中原油田天然气处理厂,濮阳457061

出　　处：《粉末冶金材料科学与工程》2017年第6期713-718,共6页Materials Science and Engineering of Powder Metallurgy

摘　　要：采用非局域热力学平衡条件,考虑等离子喷涂过程中的电离及复合反应,研究超音速等离子喷涂过程中的流场特性。结果表明,氩氢混合气体中氢气的体积分数为15%时,喷枪内部的最大速度达到3 200 m/s,最高温度达到18 000 K。采用氩氢混合气体比纯氩情况下的速度和温度都有所提高。等离子体的最大速度随电流增大而增大,最高温度在470 A出现拐点,当电流大于470 A时,气流温度开始升高。加入粉末后,气流速度增大。流场速度随载气量增大而减小。氩氢混合气体中氢气的最佳含量为体积分数15%。The jet characteristics in the supersonic plasma spraying process were investigated based on the non-local thermodynamic equilibrium conditions and considering the ionization and composite reactions during plasma spraying. The results show that the maximum velocity of 3 200 m/s and the maximum temperature of 18 000 K are obtained when H2 volume fraction in the Ar-H2 gas is 15%. Both temperature and velocity of the flow in Ar-H2 gas mixture are higher than that of in pure Ar gas. The maximum velocity of the plasma increases with increasing the current. The maximum temperature of the plasma appears at 470 A. The temperature of the gas flow increases when the current is higher than 470 A. The flow velocity increases after adding powder. The velocity of the flow field decreases with increasing the carrier gas. The optimum volume fraction of H2 in Ar-H2 gas mixture is 15%.

关 键 词：超音速 等离子喷涂 射流特性 非局域热力学平衡 氩氢混合气体 

分 类 号：O359[理学—流体力学] TG174.44[理学—力学]