钢表面激光熔覆Ti-Al球磨粉合成复合涂层
Ti-Al composite coating prepared by laser cladding on steel surface
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摘要: 为提高钢的表面硬度及耐腐蚀性,选用钛,铝机械球磨粉末在Q235钢基体表面进行激光熔覆试验,使钛,铝发生反应并制备Ti-Al金属间化合物复合涂层. 综合运用DTA、XRD和SEM分析方法对激光熔覆涂层的成分与组织进行分析,并对复合涂层的硬度及耐腐蚀性进行测试. 结果表明,机械球磨可使粉体细化,涂层与基体形成了冶金结合,涂层由Al3Ti,Al3Fe,Fe,AlN和FeO组成,同时激光熔覆涂层具有较高的硬度及优良的耐腐蚀性能. 当激光功率为1000 W,扫描速度为600 mm/min时,复合涂层同时获得最高显微硬度和耐腐蚀阻抗值,分别为949.5 HV和600 kΩ.Abstract: In order to improve the microhardness and corrosion resistance of Q235 steel, Ti-Al intermetallic compound composite coating were prepared on Q235 steel surface by using laser cladding with the addition of mechanical milled Ti, Al powder. The microstructure of Ti-Al composite coating was analyzed using DTA, XRD and SEM, while the microhardness and corrosion resistance of the cladding layers were measured. The results showed that Ti-Al mixed powders can be refined by milling. Metallurgical bonding was formed between the base metal and the cladded coating which were composed of Al3Fe, Al3Ti, Fe, AlN and FeO. The microhardness of the cladded layer was high and corrosion resistance was excellent. When the laser power was 1 000 W and scanning speed was 600 mm/min, the highest microhardness of the coating reached at 949.5 HV, and the corrosion resistance impedance could be 600 kΩ,.