激光淬火基体对铬层表面形貌的影响

Effect of a laser quenched substrate on the surface morphology of Cr-plating coatings

为了揭示激光淬火基体对电镀铬层表面形貌的影响,采用激光离散淬火基体的方法对镀铬层表面形貌进行了研究。铬层表面形成了与离散基体对应的、密实球状组织条带和疏散球状组织条带离散相间的周期性形貌;密实球状组织条带对应着原始基体区,而疏散球状组织条带则对应着激光淬火区。借助于高分辨率扫描电镜,利用化学腐蚀基体和粒子束刻蚀法分别对铬层界面和厚度方向组织形貌的进行了实验分析。结果表明,铬层表面形成了与其对应的周期性形貌,其机理是铬层界面周期形貌和铬层不同的生长方式,将激光离散基体特征传递给了铬层表面。

In order to discover the effect of a laser quenched substrate on the surface morphology of Cr-plating coatings, the substrate was quenched by laser discretely and then Cr-coatings were plated on the surface. There appeared periodical strips alternating with dense and loose ball-like microstructure on the surface morphology in accordance with discrete substrate. The dense and loose strips correspond with original and laser quenched zone respectively. With the help of high resolution scanning electron microscope, the chemically-etching substrate and ion etching methods were used to analyze the microstructure morphologies on the Cr-coating interface and along the thickness direction respectively. The results show that the mechanism of the periodical morphological formation of Cr-coating is that the substrate discrete characteristic is transferred to coating surface by means of the periodical characteristic of coating interface and differential Cr-coating growth mode.