【摘要】 为了研究热喷涂工艺对爆炸喷涂Al-Cu-Cr准晶涂层组织和硬度的影响规律,采用三种爆炸喷涂工艺参数在Q235A低碳钢基体上制备涂层,借助XRD、SEM和OM等技术手段对粉末和涂层的组织结构进行分析,并检测涂层横截面的孔隙率和显微硬度。结果表明,用于喷涂的Al₆₅Cu₂₀Cr₁₅准晶粉末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θ-Al₁₃Cr₂(即Al₈₃Cu₄Cr₁₃);而爆炸喷涂涂层中除i和θ两相外,生成了新相——体心立方结构的α-Al₆₉Cu₁₈Cr₁₃（准晶i的晶体类似相）和Al₂O₃相。涂层呈典型层状结构,其它条件不变的情况下,涂层中各晶体相与准晶相i最强峰衍射强度的比值α/i、θ/i和Al₂O₃/i随爆炸喷涂工作气体流速的成比例提高而增加,同时涂层截面的孔隙率下降而显微硬度HV_0.1升高。更多还原

【Abstract】 In order to investigate the influence of detonation spraying parameters on the rnicrostructure and hardness properties of the coatings,different process parameters were respectively used to deposit A1-Cu-Cr quasicrystalline coatings on the Q235A low carbon steel.The microstructure of the coatings and feedstock powders were characterized by means of XRD,SEM and OM.The cross section porosity levels and microhardness HV_0.1 of the coatings were measured.The results show that,the starting powders consist of a dominant icosahedral quasicrystalline phase i-Al₆₅Cu₂₄Cr₁₁ and a minor monoclinic crystalline phaseθ-Al₁₃Cr（2）(i.e.Al₈₃Cu₄Cr₁₃). However,besides these two phases,an approximant to i-Al₆₅Cu₂₄Cr₁₁,α-Al₆₉Cu₁₈Cr₁₃（body-centered cubic） and Al₂O₃ have been detected in all coatings.On the other hand,all the coatings take lamellar structures as characteristics,and for identical spraying conditions,as the working gases （i.e.C₂H₂,O₂,N₂ and air） flow rates were proportionally increased,the peak intensity ratio of the strongest peak of each crystalline phase to the i-phase,such asα/i,θ/i and Al₂O₃/i rose,and the coatings cross section microhardness HV_0.1 increased but the porosity decreased.更多还原