电触头用Cu-W合金的微观组织及抗烧蚀机理研究

通过熔渗法制备了真空断路器触头用Cu-70W, Cu-80W和Cu-90W（%，质量分数）合金，并通过激光烧蚀实验测试其抗烧蚀性能。通过实验验证及建立传热-流场耦合数学模型探究了Cu-W合金激光烧蚀过程，并解释了其抗烧蚀机理，阐明了W含量及激光功率对合金烧蚀行为的影响机制。计算和实验结果表明，激光能量沿光斑中心向外呈高斯分布，合金中靠近光斑中心和远离光斑中心的区域由于受热量递减会分别蒸发和熔化。Cu-W合金局部受热熔化，激光加热区域附近将出现沿区域中心向外发散的温度梯度，显著影响周围流场，使中心高温气流向四周低温区域流动，从而使合金熔体飞溅。通过仿真计算及实验验证，发现W的烧蚀深度约为50μm，远低于Cu的烧蚀深度（>100μm），表明高熔点的富W相可以通过减小烧蚀深度来显著提高Cu-W合金的耐烧蚀性。计算与实验结果呈现较高的匹配性，这将有助于数学模型在合金激光加工领域的应用。

Microstructure and Ablation Resistance Mechanism of Cu-W Alloy Used for Electrical Contacts

Cu-70W and Cu-90W (%, mass fraction) alloys for vacuum circuit breaker contacts were prepared through infiltration method. The anti-ablation performance of Cu-W alloys was tested through laser ablation experiments. The laser ablation process of Cu-W alloy was explored through experimental verification and the establishment of a heat transfer-flow field coupling mathematical model, and the anti-ablation mechanism was explained. Through the comprehensive analysis of calculation and experimental results, it was indicated that the laser energy exhibits a Gaussian distribution outward along the center of the spot, and the areas near and far from the center of the spot in the alloy would evaporate and melt respectively due to the decreasing heating amount. The evaporation of the alloy and the temperature gradient opposite to the direction of laser propagation would significantly affect the flow field, and cause the alloy melt to splatter outward. Through simulation calculations and experimental verification, this work quantitatively demonstrated that the high melting point of the W-rich phases could significantly improve the ablation resistance of Cu-W alloys by reducing the ablation depth.The high matching between the calculation and experimental results would contribute to the application of mathematical models in the field of alloy laser processing.