工艺参数对等离子弧快速成型Inconel 625合金组织的影响

Effects of process parameters on Inconel 625 alloy microstructure by plasma arc rapid prototyping

为了优化Inconel 625合金快速成型零件的组织和力学性能,分析了不同工艺参数对脉冲等离子弧快速成型的沉积态组织,研究其影响规律,重点分析了工艺参数对沉积态组织中的枝晶形态、相的种类、尺寸及分布特征等的影响,同时评价了在不同线能量条件下沉积态组织的生长连续性。结果表明,随着峰值电流的提高,组织会逐渐由胞状晶转变为树枝晶,且枝晶间距也随之不断增大,而Laves相的尺寸以及数量都会随之变大;同时成型速度也会对沉积态组织产生影响,其影响规律与峰值电流相反。当线能量密度P/V不超过18 k W·min/m时,其组织主要是细小的胞状晶,并且多层的沉积组织没有出现明显的转变层,组织为连续的柱状晶形态,但线能量密度P/V达到36 k W·min/m时,组织为粗大的树枝晶形态。层层之间出现明显的转变,组织为不连续柱状晶形态,同时析出相Laves在转变层枝晶间隙大量析出,组织出现严重的元素偏析。

In order to optimize the microstructure and mechanical properties of plasma arc rapid prototyping of Inconel 625 alloy,the effects of process parameters on the as-deposited structure were investigated,and the dendrite morphology,the precipitates types and distribution characteristics of the as-deposited structure under the different process conditions were analyzed.At last the continuity of structure was evaluated.The results show that the structure was transformed from cellular to dendrites with current being increased,and meanwhile the dendrite space increases,the precipitations become larger and increase in amount.The effect of welding speed is contrary to that of welding current.When the heat input P/V is less than 18 000 W·min/m,the microstructure shows cellular morphology without transformation layer.When the heat input P/V is close to 36 000 W·min/m,the microstructure becomes coarse dendrite,and the transformation layer forms between the adjacent layers.The serious element segregation,precipitation of brittleness Laves phase occur.