激光熔覆制备CrNiAlCoMoB_x系高熵合金涂层的组织与性能研究

Microstructure and Properties of CrNiAlCoMoB_x High Entropy Alloy Coating Prepared by Laser Cladding

为了拓展激光熔覆制备高熵合金涂层在材料表面改性中的应用,本文利用激光熔覆的方法在45#钢基体上制备了成形质量良好的CrNiAlCoMoBx系高熵合金涂层,并研究了激光熔覆工艺参数和B含量对涂层成形质量、微观组织结构和硬度的影响。结果表明:在优化的工艺参数下,可以得到表面形貌良好的CrNiAlCoMoBx系高熵合金涂层,涂层与基体呈良好的冶金结合,涂层由枝晶和网状共晶组织组成,均匀致密,最高硬度达到950 HV0.2,平均硬度可达700 HV0.2,是基体45#钢硬度的3倍。随着B含量的增加,裂纹减少,硬度有所降低,但始终在600 HV0.2以上;涂层的干摩擦磨损性能优于H13钢;在3.5%NaCl电解液中耐腐蚀性良好,与304不锈钢相当。

To develop the application of laser cladding for preparing high entropy alloy coating on surface modification of materials,the CrNiAlCoMoBxcoating with good formation was prepared on 45 steel by laser cladding,and the effects of laser cladding parameters and the content of B on coating quality,microstructure and hardness were investigated.The results show that CrNiAlCoMoBxhigh entropy alloy coating with good surface morphology can be prepared with the optimal processing parameters.The coating is metallurgical bonded with the substrate.The dense coating consists of dendrites and net-like eutectic structures.The maximum hardness is 950 HV0.2,and the average value of hardness reaches 700 HV0.2which is 3times of 45steel＇s.With increasing of B content in the coating,the crack reduces,and the hardness decreases but it is still higher than 600HV0.2.The dry friction and wear performance of the coating is better than that of H13 steel.The corrosion resistance of the coating in the 3.5% NaCl electrolyte is excellent that is equivalent to 304 stainless steel.