激光熔覆铁铬梯度涂层界面调控与性能研究

Laser Cladding of Iron-Chromium Gradient Coatings:Interface Regulation and Performance Improvement

为解决螺杆钻具磨损问题,通过激光熔覆技术在45钢基材上制备了铁铬梯度涂层。针对梯度涂层熔覆过程中常见的开裂问题,提出了调控熔覆层粉末成分的优化策略,采用不同碳含量的熔覆粉末构建了硬度梯度,并通过熔覆JG-3过渡层优化了界面结合。研究表明,梯度涂层硬度呈梯度上升,耐磨性逐步提升;JG-3过渡层可以促进基体与熔覆层之间的界面结合,有效连接了不同硬度的熔覆层,避免了裂纹产生;断口形貌分析表明,熔覆层呈现出典型的“河流花样”的解理断裂特征,不规则的金属氧化物可以撕裂熔覆层基体,显著降低其熔覆层性能,应对熔覆后的每层表面进行抛光处理,以保证完全清除界面间的氧化层。制备的铁铬梯度层的连接界面保持平整无裂纹。该研究结果为解决梯度涂层熔覆时的开裂问题提供了有效的解决方案与依据。

Iron-chromium gradient coatings were prepared on 45 steel substrates using laser cladding technology to address the wear issue of screw drills.To tackle the common cracking problem during the cladding process,an optimization strategy was proposed to regulate the powder composition of the gradient coatings.Gradient hardness was achieved using cladding powders with different carbon contents,and the interface bonding was improved by introducing a JG-3 transition layer.The study revealed that the gradient coatings exhibited a gradual increase in hardness and enhanced wear resistance.The JG-3 transition layer effectively promoted the interfacial bonding between the substrate and the cladding layer,connecting different hardness layers and preventing cracking.Fracture morphology analysis indicated that the cladding layer exhibited typical“river pattern”cleavage fracture characteristics.Irregular metal oxides could tear the cladding layer matrix,significantly reducing its performance.Therefore,surface polishing of each layer after cladding is recommended to ensure complete removal of interfacial oxide layers.The prepared iron-chromium gradient coatings maintained a smooth and crack-free interface,providing an effective solution and basis for addressing cracking issues during the cladding process of gradient coatings.