热喷涂镍粉在SUS304及A6063基体上的沉积行为

Deposition Behavior of Thermal Sprayed Ni Particles Deposited on SUS304 and A6063 Substrates

为阐明基体材料对单个颗粒沉积行为的影响,采用大气等离子喷涂技术将镍粉喷涂到镜面研磨后的不锈钢SUS304及铝合金A6063基体上,并通过扫描电子显微镜及聚焦离子束等技术观察在基体上收集的沉积物正面及截面形貌。结果表明:Ni在SUS304基体上呈明显的溅射沉积,单个沉积物的中心部位与周围溅射物相分离,沉积物底部及内部均可见明显气孔,溅射可能是由基体表面的吸附质在熔滴在基体表面铺展过程中脱附所导致。同时,Ni粉在A6063基体上呈现花朵状溅射,中心部位有明显的分层现象,这可能与基体材料的热导率、熔点以及基体表面吸附质的脱附等因素密切相关。

To clarify the effect of substrate materials on the deposition behavior of single particles, Ni parti cles were sprayed onto mirrored stainless steel SUS304 and aluminum alloy A6063 by atmospheric plasma spra- ying, and the top surface and cross section morphologies of the splats were observed by scanning electron mi- croscope and focused ion beam, respectively. According to the observations, the splats collected on the SUS304 substrate exhibited as splash-like shape with a center splat surrounded by a ring of fragments, and pores can be found inside the splat and at splat-substrate interface, the splashing may be induced by the de- sorption of adsorbed gas condensation on the substrate surface during the splat flattening process. The splats collected on the A6063 substrate have typical splash feature with a flower-shaped central solidified core, and multi-layer structures can be found, which may have a close relation with the substrate melting point, thermal conductivity, and the desorption of adsorbed gas condensation on the substrate surface.