无锡钢上镀铬层的晶体织构与其机械寿命的关系

Crystallographic texture of electrochemical chromium coatings on tin-free steel as related to their mechanical durability

采用 X 射线衍射研究了在接近工业条件下制备的无锡钢上薄镀铬层(0.03 μm或每面 0.22 g/m2)的晶体织构特征。实验发现,铬镀层的晶体结构含以下组分:以垂直于镀层表面的[111]为轴心的轴向分量,(111)[112]受限分量以及一个自由分量。其中[111]轴向分量为主要织构分量,是初始阶段的生长织构;(111)[112]受限分量为次要织构分量,代表了外延生长。无锡钢上镀铬层织构与亚结构的定量特征之间的规律性变化取决于沉积参数。影响无锡钢上薄镀铬层机械寿命的主要因素之一是镀层中[111]轴向织构的形成。

The features of crystallographic texture of thin （0.03 μm or 0.22 g/m^2 per side） electrodeposited chromium coatings, obtained on tin-free steel under conditions close to the industrial ones, were investigated by X-ray diffraction. It was found that the texture of chromium coatings consists of the following components： the axial component with the axis [111], perpendicular to the surface of the coating, the restricted component （111）[112] and a random component of texture. It was shown that the main texture component is the axial component with the axis [111], which is texture of growth （at the stage of its initiation）, and the secondary one is the restricted component of texture （111）[112], which is texture of epitaxial initiation. Regular changes of quantitative characteristics of texture and substructure of chromium coatings on tin-free steel depending on deposition parameters were observed. There exists an interdependence between quantitative characteristics of texture and substructure of chromium coatings on tin-free steel. It was discovered that one of the main factors influencing mechanical durability of thin chromium coatings on tin-free steel is the formation of the axial texture with the axis [111] in the coatings.