激光重熔A356铝合金表面的力学性能

采用不同的激光功率在A356铝合金表面进行激光重熔试验,分析了重熔层的组织和显微硬度,并采用三点弯曲试验研究了重熔层的力学性能以及重熔层与基体的结合性能。结果表明:与基体相比,激光重熔层的硬度得到了大幅提升;重熔层中的细晶强化及第二相弥散强化提高了重熔层的强度,延缓了重熔层中第一裂纹的发生;重熔层与基板区域具良好的冶金结合能力,界面区域无裂缝;经激光重熔处理的试样表现出了良好的表面力学性能,在1500 W及2000 W激光功率下获得的重熔层与基体间未出现分层现象。

Mechanical Properties of A356 Aluminum Alloy after Laser Surface Remelting

The technique of laser surface remelting was carried out at different power parameters on an A356 aluminum alloy surface to analyze the microstructure and microhardness of the remelting layer. A three-point bending test was then used to study the mechanical properties of the remelting layer as well as the bonding properties between the layer and the substrate. Compared with that of the substrate, we found the microhardness of the remelting layer greatly increased. Regarding other properties, both the fine grain strengthening and second phase dispersion strengthening are found to increase the strength of the remelting layer, which delays the appearance of the initial cracks in remelting layer. The remelting layer and substrate had good metallurgical bonding ability and no cracks appear at the interface. The remelting samples also show favorable surface mechanical properties with no delamination appearing between the remelting layer obtained at laser power of 1500 W or 2000 W and the substrate.