激光与光电子学进展, 2019, 56 (2): 021602, 网络出版: 2019-08-01
WC增强Ni60AA对裂纹与硬度的影响 下载: 1063次
Effect of WC-Reinforced Ni60AA on Cracks and Hardness
光学制造 裂纹 比粉 显微硬度 送粉电压比 工艺参数 比能 optical fabrication crack specific powder microhardness powder feeding voltage ratio process parameters specific energy
摘要
采用光纤激光器在冷模具钢的表面制备出含有原位WC增强的镍基合金陶瓷涂层。采用倒置金相显微镜观察熔覆层裂纹的宏观形貌以及冰晶状WC随比粉、比能和送粉电压的变化情况。采用显微硬度计测量熔覆层的显微硬度。结果表明:当WC和Ni60AA送粉电压比超过3∶2时,熔覆层的裂纹不能通过调节比粉和比能消除,熔覆层显微硬度随比能增大而减小,随比粉的增大而增大,且熔覆层的增高量符合多项式分布,准确率高达96%以上。当WC和Ni60送粉电压比低于3∶7时,WC对熔覆层的硬度基本没有影响;当送粉电压比超过4∶6时,显微硬度跳跃式增加到780 HV。根据比粉和比能公式对基体增高量和熔化深度的影响特性调节激光熔覆的工艺参数,能在消除熔覆层的裂纹的同时保持熔覆层的显微硬度在800 HV左右。
Abstract
The in-situ WC-reinforced nickel-based alloy ceramic coating is prepared on the surface of a cold die steel with a fiber laser. The inverted metallographic microscope is used to observe the macroscopic morphology of cracks in the cladding layer and the variation of the ice crystal WC with specific powder, specific energy and the powder feeding voltage. In addition, a microhardness tester is used to measure the microhardness of cladding layers. The results show that when the voltage ratio between WC and Ni60 powder exceeds 3∶2, the cracks in the cladding layer cannot be eliminated by the adjustments of specific powder and specific energy. The microhardness of the cladding layer increases with the increase of specific energy, while decreases with the increase of specific powder. Moreover, the increase of the cladding layer conforms to a polynomial distribution accuracy of up to 96%. In contrast, when the powder feeding voltage ratio between WC and Ni60 is lower than 3∶7, WC has nearly no effect on the microhardness of the cladding layer. However, when the powder feeding voltage ratio exceeds 4∶6, the microhardness jumps to 780 HV. According to the influence of the ratio between specific powder and specific energy on the increase and melting depth of the substrate, the process parameters of laser cladding are adjusted to eliminate the cracks of the cladding layer and simultaneously maintain the microhardness at about 800 HV.
李高松, 李金华, 单鹏超, 冯伟龙. WC增强Ni60AA对裂纹与硬度的影响[J]. 激光与光电子学进展, 2019, 56(2): 021602. Gaosong Li, Jinhua Li, Pengchao Shan, Weilong Feng. Effect of WC-Reinforced Ni60AA on Cracks and Hardness[J]. Laser & Optoelectronics Progress, 2019, 56(2): 021602.