The concept of gradient composite amorphous filler metal (GAFM) was utilized to solve the scientific problem of low strength caused by excessive Ti-containing brittle-hard intermetallic compounds (IMCs) generated in Ni/TiAl brazed joints through interfacial hysteresis reaction. Based on the cluster-plus-glue-atom model, the GAFMs (ZrTiNiCu/ZrVCuNi) were designed for vacuum brazing of K4169 alloy with TiAl intermetallic. And the shear strength of the joint brazed with (TiZrNiCu/ZrVCuNi) GAFM reached 344 MPa. The relation between grain boundary, solution, dislocation and strength was established. The cracks initiated from the (Ti,Zr)(Ni,Cu)+(Cr,Fe,Ni) brittle-hard phase and the plastic-tough phase (Zr,Ti)(Ni,Cu) interface in Zone II with (TiZrNiCu/ZrVCuNi) GAFMs at 1040 °C/10 min, and then extended to the (Ti,Zr)(Al,Ni,Cu)/(Ti,Zr)(Ni,Cu,Al) non-coherent interface. To regulate the distribution of the plastic-tough phase in Zone II, raising brazing temperature could promote the dissolution of Zone I into Zone II. The addition of V to the GAFMs, and mismatches increased and prompted the Ni+TiAl phase, (Cr,Fe,Ni) phase with a-value lattice distortion of 21.38%, (Ni,Cr,Fe) and ZrNi grains refinement in Zone II, where , the brazed joint strengthening effect was enhanced. The columnar grains were transformed into grains with reticulated cladding characteristics. The percentage of substructured grains increased from 46.6% to 56.3%, and the percentage of HAGBs rose to 84.7%, which inhibited dislocation migration. Therefore, the ZrNi plastic-tough phase, prohibited the expansion of the major crack generated from the (Cr,Fe,Ni) brittle-hard phase. The major crack extended to the Ti(Ni,Cu,Al) [1–10]/Ti(Al,Cu,Ni) semi-coherent interface and then to the TiAl substrate, resulting in a zigzag crack expansion.

中文翻译：

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采用梯度复合非晶态填充金属真空钎焊的 K4169 合金/TiAl 金属间接头中塑性韧性的调节具有优异的剪切强度

利用梯度复合非晶态填充金属（GAFM）的概念，解决了Ni/TiAl钎焊接头中通过界面滞后反应生成过多的含钛脆硬金属间化合物（IMC）导致强度低的科学问题。基于簇加胶原子模型，GAFM（ZrTiNiCu/ZrVCuNi）被设计用于 K4169 合金与 TiAl 金属间化合物的真空钎焊。(TiZrNiCu/ZrVCuNi)GAFM钎焊接头的剪切强度达到344 MPa。建立了晶界、固溶、位错和强度之间的关系。(TiZrNiCu)II区裂纹从(Ti,Zr)(Ni,Cu)+(Cr,Fe,Ni)脆硬相和塑韧相(Zr,Ti)(Ni,Cu)界面萌生/ZrVCuNi) GAFM 在 1040 °C/10 分钟，然后扩展到 (Ti,Zr)(Al,Ni,Cu)/(Ti,Zr)(Ni,Cu,Al) 非共格界面。为了调节II区塑韧相的分布，提高钎焊温度可以促进I区溶解到II区。添加V到GAFM中，失配增加，促使Ni+TiAl相、(Cr,Fe,Ni)相的a值晶格畸变达到21.38%，(Ni,Cr,Fe)和ZrNi晶粒在区域细化II，其中 ，钎焊接头强化效果增强。柱状晶粒转变为具有网状包层特征的晶粒。亚结构晶粒比例从46.6%增加到56.3%，HAGBs比例上升到84.7%，抑制了位错迁移。因此，ZrNi塑韧相阻止了(Cr,Fe,Ni)脆硬相产生的主裂纹的扩展。主裂纹扩展至Ti(Ni,Cu,Al)[1-10]/Ti(Al,Cu,Ni)半共格界面，然后扩展至TiAl基体，导致锯齿状裂纹扩展。