材料期刊网

目的：获得制备形貌较佳的CBN激光熔覆层的工艺参数。方法以CBN粉末为熔覆材料,在TC11钛合金表面制备CBN熔覆层。设计正交试验,利用金相法检测熔覆层的几何形貌参数,研究工艺参数(激光功率、扫描速度、离焦量、预置层厚度)对涂层几何形貌的影响规律。结果随着激光功率、扫描速度、离焦量和预置层厚度的增大,熔覆层宽度、高度以及熔池深度都发生相应的改变。其中扫描速度对熔覆层形貌的影响最大,其次为激光功率和预置层厚度,离焦量的影响最小。随着激光功率增大,熔覆层宽度先增大后减小,熔覆层高度逐渐降低,熔池深度逐渐增大。扫描速度、离焦量和预置层厚度的增加都导致熔覆层宽高和熔池深度的减小。结论最优的工艺参数为：激光功率1400 W,扫描速度4 mm/s,离焦量35 mm,预置层厚度0.4 mm。

ABSTRACT:Objective To obtain the process parameters for CBN laser cladding of better morphology. Methods The CBN coat-ings were prepared by laser cladding on TC11 titanium alloy surface with CBN powder. An orthogonal test was designed and metal-lographic method was used to detect the geometric parameters of the cladding layer. The influencing law of the processing parame-ters including laser power, scanning speed, defocusing distance and preset thickness on the laser cladding layer morphology was re-searched. Results The width, height and molten pool depth of the cladding layer were changed as the laser power, scanning speed, defocusing distance and preset thickness increased. It was concluded that the scanning speed had the most important effect, fol-lowed by the laser power and the preset thickness, and then the defocusing distance. It indicated that the width of the cladding lay-er first increased and then decreased, the height of the cladding layer increased and the depth of molten pool decreased with the in-crease of laser power. The width, height and the molten pool depth of the cladding layer decreased with the increase of scanning speed, defocusing distance and preset thickness. Conclusion The optimal processing parameters were obtained, the laser power was 1400 W, the scanning speed was 4 mm/s, the defocusing distance was 35 mm and the preset thickness was 0. 4 mm.