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Well-crystallized a-Al 2 O 3 /TiC composite coating was synthesized on the surface of steel substrate by a facile laser-assisted combustion synthesis technique without subsequent calcination. The effect of laser cladding speed on formation and microstructure of the coatings was studied. At 6 mm/s, a-Al 2 O 3 /TiC coating with good quality was obtained without pores and cracks and was well bonded with the steel substrate. By adjusting the precoating thickness, the coating thickness was easily controlled. As a simple, environmentally friendly and energy-saving technique, laser-assisted combustion synthesis is expected to find applications in ceramic coating fabrication as tritium permeation barrier or wear-and corrosion-resistance coatings. ExperimentalSteel plates (AISI 1045 steel) were used as substrates. Before precoating, substrates (50 mm 9 50 mm 9 8 mm) were polished with waterproof abrasive paper *liheping@hust.edu.cn

The martensitic lath width (0.83 ± 0.45μm ∼ 0.48 ± 0.14 μm) and dislocation density (1.3 ± 0.3 × 1015 m−2 ∼ 6.4 ± 1.6 ×1015 m−2) change of Super-clean Reduced Activation Martensitic (SCRAM) steel caused by warm deformation on Gleeble-3500 thermo-simulation machine have been examined. The irradiation-induced helium bubbles and hardening were observed in all the specimens after helium implantation to 1e + 17/cm2 at 723 K. The helium bubbles became smaller and more numerous while the distribution was more homogeneous when the lath width decrease and dislocation density increase. The nano-indentation hardness indicated that the sample, the martensitic lath width is 0.83 ± 0.45μm and the dislocation density is 1.3 ± 0.3 × 1015 m−2, exhibited the maximum nano-indentation variation (ΔH) and the ΔH decreased with the lath width decreasing and dislocation density increasing. The hardening occurred in all helium implanted samples can mainly be ascribed to helium bubbles.