异质双丝电弧喷涂制备复合涂层的工艺优化

Process optimization of a hybrid twin-wire arc sprayed composite coating

关键词:  异质双丝电弧喷涂|高速摄像|复合涂层|异步送丝

Key words:  hybrid twin-wire arc spraying|high speed photograph|composite coating|asynchronous wire feeding

摘要:

异质双丝电弧喷涂是利用两根不同材质金属丝制备复合涂层的一种工艺. 对于熔点相差较大的丝材组合，常出现高熔点材料熔化不完全、频繁断弧的现象. 为此文中提出了异步送丝的电弧喷涂方法，并对碳钢丝—铝丝双丝组合喷涂的电弧区行为展开了研究. 结果表明，异步送丝的电弧喷涂设备可有效解决熔点差别较大的异质双丝电弧喷涂时的稳定性问题. 最后使用扫描电镜和X射线衍射仪对Fe-Al复合涂层的组织进行表征，表明异质双丝电弧喷涂过程中阴阳两极材料间基本不发生冶金反应，形成的是一种铝软质颗粒和碳钢硬质颗粒交错叠加的机械混合涂层.

Abstract:

Hybrid twin-wire arc spraying is a typical process that using two different metal wires as the feeding material. For some occasions the melting point of the two wires is different highly, the higher melting point wire always does not be melted totally and the arc extinguishes frequently. In the present study, a new spraying method using asynchronous feeding for the two wires was put forward, and the arc behavior during spraying of carbon steel and aluminum twin wires was investigated. The results show that, the stability of the hybrid twin-wire arc spraying process was improved significantly when using the asynchronous feeding spray system. Finally, the structure of the Fe-Al composite coating was characterized using a scanning electron microscope and an X-ray diffraction instrument. It is manifested that metallurgical reaction is rarely generated between the anode and cathode for the hybrid twin-wire arc spraying. A mechanically mixed coating is therefore formed, in which the aluminum splats and carbon steel splats are inter-deposited.