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采用自主研制的冷喷涂设备在三种典型基板上进行喷涂试验,相同的工艺参数下,在铜和铝基板上得到良好的铜涂层,而在钢基板上则没有沉积。实验结果表明:涂层与基板界面、涂层内部颗粒界面结合良好,铜涂层组织致密,显微硬度高达150HV0.1;从涂层表面形貌扫描电镜(SEM)照片中可以观察到射流状的金属,说明颗粒发生了巨大变形,经计算知颗粒在碰撞中压缩率达69%;粉末和涂层的X射线衍射(XRD)结果表明铜粉末在冷喷涂过程中没有发生氧化。同时,数值模拟了铜颗粒与三种基板的碰撞过程,讨论了形成有效结合的判断准则,根据该准则,计算出铜颗粒在铜、铝、钢基板上的临界沉积速度分别为600m/s,500m/s,800m/s,从而解释了铜颗粒在三种基板上不同的沉积行为。
Spray tests were carried out on three typical substrates using a self-developed cold spray equipment. Good copper coating was obtained on copper and aluminum substrates with the same process parameters, but not on steel substrates. The experimental results show that the interfacial adhesion between the coating and the substrate is good and the interface of the coating is good. The copper coating is dense and the microhardness is as high as 150 HV0.1. The appearance of jet-like Of the metal, indicating that the particles have undergone tremendous deformation, and the compressibility of the particles in the collision is 69%. The X-ray diffraction (XRD) results of the powder and the coating show that the copper powder does not oxidize during the cold spraying. At the same time, the collision between copper particles and three kinds of substrates was numerically simulated, and the criterion for forming effective bond was discussed. According to the criterion, the critical deposition rates of copper particles on copper, aluminum and steel substrates were calculated as 600m / s, 500m / s, 800m / s, which explains the different deposition behavior of copper particles on three kinds of substrates.