In-situ TiB2 particle reinforced Al-5Cu alloy composites were synthesized successfully by reaction of mixed salt with aluminum melt.Microstructure and wear resistance of the prepared composites were observed by XRD（X-ray diffraction）

SEM（scanning electron microscope）and EDS（energy dispersive spectrum）and wear-frictional testing.The results show that in-situ TiB2 particle with size in approximately 500 nm is uniformly distributed into the composites

and microstructure of the composites is greatly refined.Wear resistance of the composites is obviously superior to that of matrix alloy

which is attributed to the formation of a compact mechanical-mixed layer.TiB2 particle exhibits double effects of inhibiting metal flow and taking some loading during wear testing process.