一、引言镍铝包复粉末有两种类型,一种是以镍为核心外面包复一层铝;另一种是以铝为核心外面包复一层镍。镍铝包复粉末作为结合性涂层材料在热喷涂中占有特殊地位,素有增效材料之称。Ni-Al包复粉末在热喷涂过程中发生强烈的铝化反应,金属间生成化合物放出大量的热,瞬间使粉末升至高温而成熔化或半熔化状态喷到基材上,形成结合力强的喷涂层。使涂层致密无孔,具有抗高温氧化,抗大气腐蚀、耐磨损,有良好的机加工性能。Ni-Al包复粉末在热喷涂中广泛的用作过渡层和工作层,还可作混合涂层。为研究Ni-Al包复粉末的放热反应机理和相变过程,我们通过差热分析,X光衍射法,金相、扫描电镜等手段基本弄清镍铝包复粉末在加 I. INTRODUCTION There are two types of nickel-aluminum clad powder, one is nickel clad with aluminum core; the other is aluminum clad with nickel as the core. Nickel-aluminum coated powder as a combination of coating materials in thermal spraying occupies a special position, known as synergistic materials known. Ni-Al coated powder in the thermal spraying process occurs in the strong aluminum reaction, the intermetallic compound emits a lot of heat, instantly make the powder up to high temperature into a molten or semi-molten state sprayed onto the substrate, the formation of strong binding The spray coating. Make the coating non-porous, with high temperature oxidation, anti-atmospheric corrosion, abrasion resistance, good machinability. Ni-Al coated powder widely used in thermal spraying transition layer and working layer, but also for mixed coatings. In order to study the exothermic reaction mechanism and phase transformation process of Ni-Al coated powder, we basically understand the properties of Ni-Al clad powder in differential thermal analysis, X-ray diffraction, metallographic examination and scanning electron microscope