电解腐蚀导致激光熔覆Mn-Cu合金涂层晶体结构改变的研究

Crystal Structure Transformation of Laser Cladded Mn-Cu Alloy Coatings Induced by Electrochemical Etch

激光加工制备的Mn-Cu合金涂层对于纳米多孔涂层的制备具有重要的研究意义。本文采用激光熔覆与快速激光熔凝相结合的方法在中碳钢基体表面制备了成形良好、稀释率低并与基体成冶金结合的Mn-Cu合金涂层。对合金涂层进行了特定参数不同时间的电解腐蚀处理,并对处理后的涂层材料进行X射线衍射分析,研究了Mn-Cu合金涂层在电解腐蚀过程中的晶体结构改变过程。结果表明,未经处理的合金涂层具有单相固溶体结构(Cu,γMn);在电解腐蚀过程中随着Mn元素的溶解,有新的纯Cu晶体形核长大,剩余的(Cu,γMn)固溶体中的Mn含量也逐渐降低;经彻底电解腐蚀后,涂层的晶体结构由单相(Cu,γMn)转变为具有纳米多孔结构的单相Cu。

Laser processed Mn-Cu alloy coatings play an important role in the preparation of nanoporous coatings. In this work, Mn-Cu alloy coatings with fine shape, low dilute ratio and metallurgical bond to the substrate＇were fabricated on the surface of a medium carbon steel substrate using laser cladding and high speed laser remelting. Then the alloy coatings were electrochemically etched with specific parameters for different times, the crystal structure transformation in this process was investigated using XRD. The unetched coatings have a single phase of solid solution （Cu,γMn）. Pure Cu crystals nucleate and develop during the etching process with Mn content in （Cu,γMn） decreasing. The crystal structure transforms to single phase Cu with nanoporous microstructure after thorough etching.