厚镍基激光熔覆层的研究

Thick Ni-based Powder Coating by Laser Cladding

通过对激光熔覆表面处理技术所需粉末材料的分析,成功配制了能够熔覆厚度达10mm以上且表面光滑无气孔和裂纹的镍基粉末材料。分析测试表明,镍基熔覆层的热膨胀系数小于基体45号钢,凝固时受压应力作用不会产生裂纹。合金粉末中的Fe、Co等元素有利于提高熔覆层的性能,降低裂纹敏感性。在镍基熔覆层中得到大块不完全非晶,其优越的力学性能有利于提高熔覆层的抗裂性。

Ni-based powder that can form the cladding coating with 10 mm in thickness and smooth surface and gas hole-crack free is successfully prepared based on the analysis of powder materials requirements in laser cladding process. The results reveal that the thermal expansion coefficient of the Ni-based cladding coating is less than that of 45# steel matrix,resulting in the absence of crack in pressure during solidification. Fe and Co elements in powder are beneficial to improving the properties of the cladding coating to decrease the crack susceptibility. Non-complete bulk amorphous phase in the Ni-based cladding coating can be observed,which can greatly improve the crack resistance of the cladding coating because of its desirable mechanical properties.