Microstructures and dry sliding wear properties of in situ (Al3Zr + ZrB2)/Al composites

In situ Al–xwt.%(K2ZrF6–KBF4) (x = 10, 15, 20, 25) composites reinforced by Al3Zr and ZrB2 particles were prepared via magnetochemistry in situ reaction and the dry sliding wear properties of the composites were investigated. The XRD results showed that the components of the as-prepared composites consist of Al3Zr, ZrB2 and α-Al phases. The SEM analysis indicated that ZrB2 and Al3Zr reinforcement particles were distributed uniformly in the aluminum matrix. The morphologies of ZrB2 and Al3Zr particles present in regular hexagon and tetragonal shapes, and the sizes were about 0.3–0.5 μm, respectively. Wear test results showed that the values of wear weight loss of the composites decrease with the increase of x under a given sliding time and the load of 100 N. The wear resistance R changed with variations of the sliding time stages, applied load and x. In particular, when x = 25, the wear weight loss under a sliding time of 120 min and R under the intermediate wear-sliding stage were 0.245 and 4.772 to that of the A356 alloy, reached 33.642 mg and 5.114, respectively.