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采用大功率CO2激光器研究Al-ZL101/TiB2-Al三层板激光焊接,根据扫描电镜(SEM)及维氏硬度计观察并测量焊后各层TiB2分布及焊缝硬度,得出了在激光焊透及未焊透时的熔池流动状态。结果表明,在激光未穿透焊接时,熔池内存在一个对流环,其对流在小孔缩颈处最为强烈,此处硬度值最大,TiB2体积分数最高,而在熔池底部对流最弱,硬度值最低,TiB2体积分数最小;在激光全焊透焊接时,熔池在上下两个表面分别存在对流环,下表面对流比上表面对流更为强烈,其硬度值较大,TiB2体积分数较高,对流在焊缝中间层两对流环连接处最弱,此处对流流失的TiB2最少,使得TiB2体积分数最大,硬度值最高。
The laser welding of Al-ZL101 / TiB2-Al three-layer plate was studied by using high-power CO2 laser. The distribution of TiB2 and the hardness of weld were observed and measured by scanning electron microscope (SEM) and Vickers hardness tester. Pouring and penetration of molten pool flow state. The results show that there is a convection loop in the weld pool when the laser is not penetrating. The convection is the most intense at the constriction of the pinhole, where the hardness value is the highest, the TiB2 volume fraction is the highest, and the convection is the weakest at the bottom of the weld pool. The hardness The value of TiB2 is the lowest and the volume fraction of TiB2 is the smallest. When the laser welding is completed, the convection loop exists on the upper and lower surfaces of the weld pool. The convection of the lower surface is more intense than that of the upper surface. The hardness value is larger and the TiB2 volume fraction is higher The convection is the weakest in the junction of two convection loops in the middle layer of the weld, where the convection losses are the least, resulting in the largest TiB2 volume fraction and the highest hardness value.