以6063Al-Na2B4O7-K2ZrF6为反应体系,采用Na2B4O7取代传统的KBF4,并通过两步法,原位超声复合制备纳米ZrB2/6063Al复合材料.该工艺在减少氟盐用量的同时,提高了B元素的吸收率.利用XRD,SEM等测试手段分析了复合材料的相组成和微观组织,并通过电子拉伸试验机测试复合材料的力学性能.研究结果表明,所制备出的ZrB2颗粒呈多边形状,绝大部分分布在晶界处;通过引入超声波作用,ZrB2颗粒趋于弥散并且细化,尺寸为30~90 nm;与基体相比,所制备的纳米复合材料在保持良好塑性的同时,强度大幅提高,且随着颗粒体积分数的增加,复合材料的强度呈先增大后减小趋势(最大抗拉强度为190 MPa),延伸率呈减小趋势;复合材料拉伸断面上存在大量韧窝,表明为韧性断裂.
In-situ nano ZrB2/6063Al composites were synthesized using Na2B4O7 instead of KBF4 by two-step procedure Method under high intensity ultrasonic field in 6063Al-Na2B4O7-K2ZrF6 system.The process reduces the dosage of fluoride salt,at the same time B elements absorption rate improves.The phase composition and microstructure of the composite were investigated by XRD and SEM,and the mechanical properties were studied by electronic tensile test machine.The results indicate that the ZrB2 particulates present polygon,which disperse in the grain boundary chiefly.While the ultrasonic filed is introduced,particles are refined and the size ranges from 30 to 90 nm.Comparing with the martix,the prepared nano composite has a good elongation as well as the strength.With the increase of volume fraction,the tensile strength of the composite increases first and then decreases(the highest tensile strength of the composite is 190 MPa),and the ductility presents decreased trend.The observation of fracture surface of the composite shows that large dimples consist on the section and the fracture mechanism is plastic fracture.
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