CuSn18Ti9合金超声辅助激光熔覆特性的仿真与实验研究  

Simulation and Experimental Investigation of the Ultrasonic-assisted Laser Cladding Characteristics of the CuSn18Ti9 Alloy

作　　者：李亚敏[1,2] 杨志波[1,3] 赵波[1] 王蔚 郭强[1] 张雁儒[1] LI Yamin;YANG Zhibo;ZHAO Bo;WANG Wei;GUO Qiang;ZHANG Yanru(Henan Polytechnic University,Henan Jiaozuo 454003,China;Xinxiang University,Henan Xinxiang 453003,China;Hebi Polytechnic,Henan Hebi 458030,China)

机构地区：[1]河南理工大学,河南焦作454003 [2]新乡学院,河南新乡453003 [3]鹤壁职业技术学院,河南鹤壁458030

出　　处：《表面技术》2025年第7期162-179,共18页Surface Technology

基　　金：国家自然科学基金(U1904170);企业合作项目(HT19-364)。

摘　　要：目的采用超声辅助激光熔覆技术制备的CBN/CuSnTi砂轮中熔池温度场分布及其流场状态直接影响砂轮质量,揭示熔池温度场、流场对熔覆层形貌的影响机理,从而减少砂轮熔合不良、变形开裂、组织不均匀等缺陷。方法基于45号钢基体和CuSn18Ti9结合剂的时变热物理属性,建立同轴送粉激光熔覆过程中温度场和流场的耦合仿真模型,考虑超声振动、环境温度和马兰戈尼效应的影响,并基于动网格法形成的温度场拟合熔池的形貌,研究同一工艺参数下单道单层熔覆过程中环境温度和超声振动对熔池温度场和流场的影响规律,以及熔覆过程中由熔池流场流体效应变化导致熔池温度场和形貌变化的规律。结果与基体室温、无超声作用相比,基体室温下的超声作用使得熔覆初期传导热通量减小了2.19%,熔池回流涡旋中心下移7.8%,熔覆层高、深、宽增幅依次为-1.67%、1.02%、9.69%;与基体预热573.15 K下无超声作用相比,基体预热573.15 K下的超声作用可使同一时刻温升梯度增幅下降3.92%,熔池回流涡旋中心下移11.96%,熔池最低流速增加1.49倍,熔池最高流速增加1.07倍,熔覆层高度、深度、宽度增幅依次为14.3%、14.8%、0.68%。结论在室温状态下(基体温度为298.15 K),超声对熔池流场、温度场和熔覆层形貌的影响不显著,基体预热和超声辅助均会对熔池温度场和流场产生影响,其中基体预热和超声的双重耦合作用的影响最为显著。Ultrasonic-assisted laser cladding preparation of CBN/CuSnTi grinding wheels directly impacts the wheel quality through the distribution of molten pool temperature fields and the state of its flow field.The work aims to reveal mechanisms affecting the cladding layer morphology and reduce defects such as poor fusion,deformation cracking,and uneven structure.A coupled simulation model of temperature fields and flow fields during coaxial powder feeding laser cladding was established based on the time-varying thermophysical properties of 45 steel substrate and CuSn18Ti9 binder.The model considered the effects of ultrasonic vibration,ambient temperature,and the Marangoni effect.A dynamically meshed temperature field was used to approximate the molten pool shape and the effect of ambient temperature and ultrasonic vibration on molten pool temperature fields and flow fields was investigated under consistent process parameters during single-pass single-layer cladding.Additionally,it examined how variations in molten pool flow field fluid dynamics during the cladding process affected temperature fields and molten pool morphology.Under equivalent laser process parameters,at room temperature(substrate temperature 298.15 K),the temperature gradient during the temperature rise phase under no ultrasound was 435 K/s,and during the cooling phase,it was 161 K/s.With ultrasound,the temperature gradient during the rise phase was 344 K/s,and during the cooling phase,it was 160 K/s.The molten pool flow field exhibited an asymmetric double horseshoe shape with a maximum velocity of 0.0176 m/s.Ultrasonic vibration reduced the gradient of liquid flow velocity driven by surface tension gradients behind the laser source movement,and shifted the center of the recirculation vortex generated by Marangoni force downwards by 7.8%.Under room temperature conditions with ultrasound,the molten pool height,depth,and width increased by-1.67%,1.02%,and 9.96%,respectively,compared to conditions without ultrasound.Compared to room temperature,at a subs

关 键 词：CuSn18Ti9 超声振动 激光熔覆 熔池形貌 Marangoni惯性力 

分 类 号：TG174.4[金属学及工艺—金属表面处理]