TiB2增强铝基复合材料丝材电弧增材成形研究

Research on arc additive manufacture forming of TiB2 reinforced aluminum matrix composite wire

  • 摘要:
    目的 以TiB2/6056复合材料丝材为焊材,采用冷金属过渡辅助脉冲模式(CMT+P)为加热方式,探索TiB2增强铝基复合材料丝材的电弧增材工艺。
    方法 采用Simufact welding软件模拟单层多道增材温度场,进行单层多道增材试验及微观组织分析。
    结果 工艺研究结果表明,脉冲电流140 A,送丝速度8 m/min,焊接速度5 mm/s,为最佳的复合材料丝材增材参数;搭接间距为0.736倍单道焊道宽度时,单层多道增材层成形良好,表面平整。
    结论 模拟和试验结果均证实,单层多道增材过程中,正在焊接焊道受前面焊道和后面焊接焊道的热作用均较大,导致焊后晶粒尺寸粗大。气孔大多位于焊道间熔合区处,TiB2颗粒呈聚集态分布在α-Al的枝晶之间。

     

    Abstract: Objective Arc additive manufacturing process of TiB2 particle reinforced aluminum matrix composite wire was explored in this paper. TiB2/6056 aluminum matrix composite wire was used as welding material, and cold metal transition with addition of pulse (CMT+P) was employed as heating method. Methods The temperature field distribution of single-layer and multi-bead additive part was simulated by Simufact welding software. The single-layer and multi-pass additive part was produced, and the microstructures were observed and analyzed. Results The results of process test showed that when the current was 140 A, wire feeding speed was 8 m/min, welding speed was 5 mm/s, and the forming performance of additive part was the best. The overlapping width was 0.736 times that of the bead width, which was suitable for the inter pass lap forming of single-layer and multi-bead additive with smooth and uniform surface. Conclusion The simulation and experiment results both testified that during single-layer and multi-pass additive manufacturing, the welding beads were greatly affected by the heat of the welded beads and the following beads, which led to form the coarse-grained microstructures. Porosities were mostly distributed at fusion zone between of adjacent beads. TiB2 particulates were aggregated at the grain boundary of α-Al.

     

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