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...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。展开更多
Three kinds of MCrAlY coatings with different aluminum contents （5%, 8%, 12%） were prepared by electrospark deposition （ESD）, their microstructure and oxidation behavior were studied by SEM and XRD. The results...Three kinds of MCrAlY coatings with different aluminum contents （5%, 8%, 12%） were prepared by electrospark deposition （ESD）, their microstructure and oxidation behavior were studied by SEM and XRD. The results showed that the phase composition of the coatings changed from single γ-Ni to γ-Ni＋β-NiAl hypoeutectic to γ-Ni＋β-NiAl hypereutectic with increasing aluminum content, and their solidification morphologies changed from cluster of cellular structure to cellular dendrites to coarse dendrites with secondary arms. When exposed at 1000 ℃, the coatings with higher Al content had a stronger tendency to form θ-Al2O3 in the initial several hours. After 100 h of oxidation, a dense and adherent α-Al2O3 scale formed on all of the three coatings but the thickness of α-Al2O3 scale and the amount of remaining θ-Al2O3 increased with increasing Al content. These results revealed different characteristics of ESD MCrAlY coatings which could provide scientific guidance for industrial application.展开更多
文摘为了优化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。
基金Project(50901081)supported by the National Natural Science Foundation of China
文摘Three kinds of MCrAlY coatings with different aluminum contents （5%, 8%, 12%） were prepared by electrospark deposition （ESD）, their microstructure and oxidation behavior were studied by SEM and XRD. The results showed that the phase composition of the coatings changed from single γ-Ni to γ-Ni＋β-NiAl hypoeutectic to γ-Ni＋β-NiAl hypereutectic with increasing aluminum content, and their solidification morphologies changed from cluster of cellular structure to cellular dendrites to coarse dendrites with secondary arms. When exposed at 1000 ℃, the coatings with higher Al content had a stronger tendency to form θ-Al2O3 in the initial several hours. After 100 h of oxidation, a dense and adherent α-Al2O3 scale formed on all of the three coatings but the thickness of α-Al2O3 scale and the amount of remaining θ-Al2O3 increased with increasing Al content. These results revealed different characteristics of ESD MCrAlY coatings which could provide scientific guidance for industrial application.
