摘要
为探究激光熔凝工艺对铁基粉末冶金齿毂组织及力学性能的影响。分别采用不同的激光熔凝功率制备样品,并通过着色渗透探伤、金相显微镜、SEM、XRD、维氏显微硬度计等设备对试样的形貌、微观组织、物相、显微硬度开展表征工作。研究结果表明:合理参数的激光熔凝处理可以在齿毂制品表面获得质量良好、一定厚度的硬化层;经过激光熔凝处理,齿毂表面经历快速熔化与凝固,熔凝层最终形成隐晶马氏体与残余奥氏体组织;由于熔凝层不同深度区域的温度梯度存在差异,其凝固组织主要由上部等轴树枝晶,中部柱状树枝晶与等轴树枝晶,底部柱状树枝晶与胞状晶构成;在100~300 W功率范围内,随着激光功率的提升,熔凝层厚度不断增加,相应的硬度也呈现出升高变化趋势。激光功率为200 W时,熔凝层表面质量、厚度及显微硬度等综合指标最佳,熔凝层厚度约为300μm,熔凝层显微硬度至少为基体的2.6倍,硬度为710~790 HV。
In order to investigate the effect of laser melting process on the microstructure and mechanical properties of iron based powder metallurgy gear hub,the samples were prepared with different laser melting parameters,and the morphology,microstructure,phase and microhardness of the samples were characterized by color penetration testing,metallographic microscopy,SEM,XRD,Vickers microhardness tester and other equipment.The results show that the hardening layer with good quality and certain thickness can be obtained on the surface of the gear hub products by laser melting treatment with reasonable parameters.After laser melting treatment,the surface of the gear hub undergoes rapid melting and solidification,and the fused layer eventually forms cryptocrystalline martensite and residual austenite structures.Due to the differences in temperature gradient in different depth regions of the melting layer,the solidification structure is mainly composed of the upper equiaxial branch crystal,the middle columnar dendrites and equiaxial branch crystal,and the bottom columnar dendrites and cellular crystals.In the power range of 100~300 W,with the increase of laser power,the thickness of the melting layer continues to rise,and the corresponding hardness also shows an increasing trend.When the laser power is 200 W,the comprehensive indicators of the fused layer,such as surface quality,thickness,and microhardness,are optimal.The thickness of the fused layer is approximately 300μm,and its microhardness is at least 2.6 times that of the substrate,with a hardness range of 710-790 HV.
作者
王靖超
李勇
胡勇
李贵铭
陈少武
高尧
WANG Jingchao;LI Yong;HU Yong;LI Guiming;CHEN Shaowu;GAO Yao(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Zhejiang Industry&Trade Vocational College,Wenzhou 325026,China;Zhejiang Xunda Industrial Technology Co.,LTD.,Wenzhou 325204,China)
出处
《粉末冶金工业》
北大核心
2025年第1期58-64,共7页
Powder Metallurgy Industry
基金
温州市重大科技创新攻关项目(ZG2021015)
校企合作科研项目(H2021030)
关键词
铁基粉末冶金
激光熔凝处理
熔凝层
显微组织
显微硬度
iron based powder metallurgy
laser melting treatment
fused layer
microstructure
microhardness
作者简介
王靖超(1997-),男,硕士,主要研究方向为激光表面工程;通信作者:李勇(1976-),男,硕士,副教授,主要研究方向为新型金属材料成形及表面处理技术;通信作者:胡勇(1977-),男,博士,教授,主要研究方向为新材料非平衡制备、凝固组织控制与性能设计研究。
