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为研究Al/Fe复合粉末在冷喷涂沉积过程中的粒子碰撞变形行为、结合机理及涂层组织结构特征,以机械混合Fe、Al粉末为喷涂原料(w(Al)∶w(Fe)=85∶15),使用冷喷涂沉积Al/Fe金属复合涂层。用扫描电镜(SEM)、X射线衍射仪(XRD)及显微硬度仪等分析Al/Fe复合涂层的显微组织、相结构、硬度及Fe、Al粒子的变形形貌。结果表明:Al粒子在沉积过程中由于发生强烈塑形变形明显扁平化,并通过机械咬合形成致密的基体相,而硬度较高的Fe粒子则变形较少,基本保持初始形貌并弥散分布在Al基体之中;Al粒子内部靠近碰撞界面处的晶粒由于强烈变形被明显拉长,而远离碰撞界面的晶粒则保持近似球形;冷喷Al/Fe金属复合涂层的相结构与初始喷涂粉末完全相同,涂层组织致密,孔隙率约为1.2%,涂层的硬度显著高于初始粉末。
In order to study the particle collisional deformation behavior and bonding mechanism of Al / Fe composite powders during cold spraying, the mechanical properties of the coatings were characterized by mechanical mixing of Fe and Al powders (w (Al): w (Fe) = 85 : 15), Al / Fe metal composite coatings were deposited using cold spray. The microstructure, phase structure, hardness and deformation morphology of Fe and Al particles were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and microhardness tester. The results show that the Al particles are obviously flattened due to the intense plastic deformation during the deposition process, and the dense matrix phase is formed by mechanical bite. However, the Fe particles with higher hardness are less deformed and maintain the initial morphology and are dispersedly dispersed Al matrix. The grains close to the collision interface in Al particles are obviously elongated due to the strong deformation, while the grains far away from the collision interface remain approximately spherical. The phase structure of the cold-spray Al / Fe metal composite coating is similar to the initial spray Powder exactly the same, the coating dense, porosity of about 1.2%, the hardness of the coating was significantly higher than the initial powder.