宽带激光熔覆WCp/Ni基合金梯度复合涂层的组织和耐磨性

Microstructure and Wear Resistance of Gradient Composite Coating of Cast WCp/Ni Based Alloy Cladded by Wide-Band Laser

为了消除激光熔覆过程中产生的裂纹 ,设计了一种梯度复合涂层并研究了其组织和耐磨性。结果表明 ,熔覆层与基材之间形成了良好的冶金结合。梯度复合涂层中有未完全溶化的铸造WCp和共晶组织γ- Ni+Ni3B,还有凝固结晶析出的白色不规则块状组织 M7C3、M6 C、WC以及深灰色不规则块状组织 W2 C。复合涂层中形成了少量的非晶、纳米晶及高密度位错。复合涂层耐磨性的最高值是基材的 3倍以上。

In order to eliminate cracks produced in the process of laser cladding, a kind of gradient composite coating was designed. The microstructure and wear resistance of gradient composite coating of WCp/Ni based alloy cladded by wide band laser were studied. The results indicated that the excellent metallurgical bonding is formed between cladded layer and substrate. There are γ Ni dendrite structure, γ Ni+Ni 3B eutectic structure, precipitation phases such as M 7C 3, M 6C, WC as well as W 2C in the gradient composite coating, and there are also a small number of substructures such as amorphous and nanocrystal particles as well as high density dislocation in the composite coating. The highest value of wear resistance of the composite coating is over four times more than that of substrate.