摘要
对TiB_2/ZL101复合材料和ZL101基体合金进行激光焊对比研究,结果表明:TiB_2/ZL101复合材料对激光的吸收率大于ZL101基体合金,相同工艺参数焊接时复合材料的焊接深度大于基体合金。由于基体合金导热率较大,使得焊缝上部比复合材料焊缝较宽。在功率一定时,较快的焊接速度(3 m/min)使得基体合金焊缝组织为α相和分布在α相间的针列状共晶体复合组织;而在较慢的焊接速度(2 m/min)时,基体合金焊缝组织为α相和分布较均匀的块状或长针状共晶Si相。复合材料在较快的焊接速度(3 m/min)时,晶界壁较薄,仅有少量共晶Si存在,在较慢的焊接速度(2 m/min)时,晶界壁明显变厚,共晶Si相较多。通过测试两种不同焊接速度的ZL101合金焊缝硬度表明,焊缝硬度值均比母材高,但共晶Si以针状或块状存在的焊缝硬度值小于针列状形式存在的焊缝硬度值。
TiB_2/ZL101 composites and ZL101 base alloys were welded with laser welding respectively. The experimental results show that the absorption rate to laser of TiB_2/ZL101 composite is higher than that of ZL101. Under the same processing parameters, the welding depth of composite is larger than that of ZL101. But due to the high heat conductivity of base alloy,its upper weld bead is wider than that of the composite. When the laser power is fixed, the effect of welding speed on the microstructure of the weld bead is prominent. When the speed is 3 m/ min, the microstructure of the weld bead is composed of α phase and feather-needle like eutectic (α+ Si) phase. When the speed is 2 m/min, the microstructure is composed of α phase and needle or block eutectic Si phase. However,for the composite,when the speed is 3 m/min,grain boundary wall is thin and there is a little eutectic Si phase in weld bead. When the speed is 2m/min,the grain boundary wall turns wide and there is much eutectic Si phase. The hardness of the weld bead for ZL101 alloys is higher than base material. The hardness of the weld bead which is composed of α phase and feather-needle like eutectic (α+Si) phase is higher than that which is composed of α phase and needle or block eutectic Si phase.
出处
《焊接》
北大核心
2010年第3期48-52,共5页
Welding & Joining
