石墨烯对激光熔覆钴基合金组织和性能的影响

Effect of Graphene on the Microstructure and Properties of Laser Cladding Cobalt-Based Coatings

为了研究石墨烯对激光熔覆钴基合金涂层显微组织与性能的影响,选用合金化的Stellite6粉末和石墨烯混合作为熔覆材料,在同一工艺参数下在00Cr13Ni4Mo马氏体不锈钢上制得石墨烯质量分数为0.5%~2.0%的复合涂层。结果表明:激光熔覆过程使少量石墨烯烧损,部分得以保留;当石墨烯含量达到1.5%时涂层出现了较明显的裂纹;随着石墨烯含量的增加,涂层的硬度最高达到720 HV;当石墨烯含量为0.5%时,磨损量由2.31 mg减小至1.96 mg,涂层耐磨性提高,过量的石墨烯使涂层耐磨性下降;当石墨烯含量为0.5%~1.0%时,空泡腐蚀失重约为Stellite6涂层的1/3,涂层的抗空蚀性能提高,超过1.0%时涂层因出现裂纹缺陷导致抗空蚀性能显著劣化。

For studying the effect of graphene on the microstructure and properties of laser cladding cobalt-based alloy coatings, mixed alloyed Stellite6 powder and graphene were selected as the cladding material, and the composite coatings with the graphene mass fractions of 0.5%~2.0% was prepared on 00Cr13Ni4Mo martensitic stainless steel under the same process parameters. Results showed that a small amount of graphene was burned out during the laser cladding process, and part of the graphene was retained. When the graphene content reached 1.5%, obvious cracks appeared in the coating surface. With the increase of graphene content, the hardness of the coating reached 720 HV. When the graphene content was 0.5%, the wear loss of the coating decreased from 2.31 mg to 1.96 mg, the wear resistance of the coating increased, and the excessive graphene reduced the wear resistance of coatings. When the graphene content was 0.5%~1.0%, the cavitation corrosion loss was about 1/3 of that of the Stellite6 coating, and the cavitation resistance of the coating was improved. When the graphene content exceeded 1.0%, the cavitation corrosion resistance of the as-obtained coating declined significantly due to crack defects.