基体热导率对超音速火焰喷涂Al-Cu-Cr准晶涂层相组成的影响

Influence of substrate thermal conductivity on the phase composition of high velocity oxy-fuel sprayed Al-Cu-Cr quasicrystalline coatings

为研究基体热导率对超音速火焰(HVOF)喷涂Al-Cu-Cr准晶涂层相组成的影响规律,采用相同的热喷涂参数,分别在304不锈钢、45#钢、工业纯铝和紫铜基体表面制备涂层.X射线衍射分析结果表明:喷涂准晶粉末Al65Cu20Cr15中含有二十面体准晶相I-Al65Cu24Cr11和极少量具有单斜结构的晶体相-θAl13Cr2(即Al83Cu4Cr13);而超音速火焰喷涂形成涂层中除这两相外,还生成了一种新相,即具有体心立方结构的晶体相-αAl69Cu18Cr13,为I相的晶体类似相.晶体相θ和α与准晶相I之间对应衍射峰的强度比值θ/I和α/I随基体热导率的提高而增大.304不锈钢为基体的涂层中,准晶相I含量比紫铜为基体的涂层中的高,而晶体相θ和α的含量比后者低.

Al-Cu-Cr quasicrystalline coatings were prepared on AISI304, 45 steel, Al and Cu substrates respectively using identical high velocity oxy-fuel （HVOF） spray parameters to investigate the influence of substrate thermal conductivity on the phase composition of the coatings. X-ray diffraction （XRD） results show that the feedstock powders consist of a dominant icosahedral quasicrystalline phase Ⅰ -Al65 CU24 Cr11 and a minor monoclinic crystalline phase 0 - Al13 Cr22 （ i. e. Al83 Cu4Cr13 ）. However, besides these two phases, an approximant to Ⅰ - Al65 CU24 Cr11, a - Al69 Cu18 Cr13 （body-centered cubic） was detected in all coatings. The phase assemblage of the as-sprayed coatings was affected significantly by substrate thermal conductivity. The XRD α/Ⅰ and θ/Ⅰ peak intensity ratios increase with the substrate thermal conductivity rising. The amount of Ⅰ in the coating deposited on AISI304 substrate is larger than that on Cu, but the amount of α and θ is less than the latter.