化学沉积非晶态Ni-W-P合金激光晶化组织与耐磨性的关系

用XRD定量分析法研究化学沉积非晶态Ni-W-P合金激光晶化前后的显微组织特征.通过硬度测试、磨损实验、金相和SEM研究镀层的磨损行为.结果表明:在不同的扫描速率下,均发生Ni3P相的晶化反应；随扫描速率的降低,镀层的晶化程度增加,但均未达到完全晶化；扫描速率为7mm/s时,镀层的晶化程度为73.0％.在发生Ni3P晶...

Wear Resistance and Microstructural Correlation for Amorphous Electroless Ni-W-P Coatings Crystallized by Laser

The microstructural characteristics of the amorphous electroless Ni-W-P coatings before and after laser crystallization were evaluated by a quantitative XRD method.Wear behaviour of the coatings were investigated by means of measurement of microhardness,wear test and optical microscope and SEM observation.The results indicate that crystalline reaction of Ni3P phase occurs at different scanning velocities.The crystallization degree of the coating increases with the decreasing scanning velocity,but there is an incomplete crystallization for all coatings.At the scanning velocity of 7mm/s,the crystallization degree is 73.0%.The size of precipitated Ni3P is larger than Ni at the scanning velocity(10mm/s) of critical precipitation of Ni3P phase.The evolution of magnitude of both phases is opposite while the scanning velocity decreases.The sizes of both phases are in the range of nano-scale during the process of laser crystallization.Microhardness and wear resistance of the coating before and after laser crystallization are affected by the crystallization degree,relative proportions of Ni and Ni3P phases as well as grain sizes.Adhesive wear dominates at 7mm/s,and abrasive wear is the major form of the coating at 8mm/s.The wear resistance of the coating can be improved with fitting crystallization degree and suitable sizes of both phases.