The Stellite SF12-TiC-Mo-Sn laser melt deposited (LMD) composite coating was produced on a TA1 titanium alloy. Such composite coating was researched using scanning electron microscope (SEM) and a high-resolution transmission electron microscope (HRTEM). It was confirmed that Ti3Sn nanocrystals appeared at an intersplat region, which was very compatible to the d-space of the Ti3Sn at an orientation of (101). The Ti3Sn particles were surrounded by the amorphous phases. Under the action of such composite coating, the micro-hardness distribution of the substrate surface is in a range of 1350-1500 HV0.2, and the wear volume loss is 1/13 of a TA1 alloy. K e y w o r d s : titanium, sliding wear, lasers, composites

2024 aluminum alloy sheets in T4 temper were welded successfully by friction stir welding (FSW) technique. When the welding travel speed was 300 mm min −1 , tensile strength reached a maximum value (294 MPa). The precipitated phase is mainly metastable U (AlCuMg) of reinforced phases in thermo-mechanically affected zone (TMAZ). Lots of the AlCu3 black particles precipitated on the grain boundary of TMAZ. However, a large number of Cu2Mg black granular precipitates were observed in the WN region.