AZ91D熔体中原位合成TiC颗粒及冲刷腐蚀性能

利用原位合成反应法,在不同温度(740、760和780℃)下对AZ91D镁合金熔体保温40min,制备了TiC/AZ91D镁基复合材料。借助光学显微镜和X射线衍射仪,对TiC/AZ91D镁基复合材料的组织形貌和物相进行观察和分析,并对制备的复合材料在质量分数为3.5%的NaCl溶液+石英砂条件下进行冲刷腐蚀磨损试验。结果表明,在740℃保温40min制备的复合材料主要由α-Mg、β-Mg17Al12和Al3Ti组成。保温温度分别为760℃和780℃时,AZ91D镁合金中均出现了原位合成的TiC颗粒,并且随温度升高,TiC的数量增加。此外,TiC/AZ91D镁基复合材料在3.5%的NaCl溶液+石英砂中的冲刷腐蚀磨损性能随保温温度的升高而增加。经780℃保温40min后的复合材料呈出最好的耐冲刷腐蚀磨损性能,相比于AZ91D镁合金提高了60.5%。

Preparation and Scour Corrosion Properties of In-situ Synthesized TiC Particles in AZ91D Melt

TiC/AZ91D magnesium matrix composites were prepared at different temperatures(740℃,760℃ and 780℃)for 40 min by in-situ synthesis reaction method.The microstructure and phase of TiC/AZ91D magnesium matrix composites were observed and analyzed by means of optical microscope and X-ray diffractometer.The erosion corrosion wear test of the prepared composites was performed in 3.5% NaCl solution and quartz sand.The composites are mainly composed ofα-Mg,β-Mg17Al12 and Al3Ti at 740℃ for 40 min.In situ synthetic TiC particles appear in AZ91D magnesium with holding at 760 ℃ and 780 ℃,respectively.Furthermore,the number of TiC particles is increased with increasing in temperature.Meanwhile,the erosion corrosion wear properties of TiC/AZ91D magnesium matrix composites in 3.5% NaCl solution and quartz sand is improved with the increase of holding temperature.At 780℃,the composites present the desirable erosion corrosion wear behavior which is increased by 60.5%compared with that of AZ91D magnesium.