本研究中嘗試接合Ti-6Al-4V(Ti-64)與其它異種金屬。研究中使用Ag-Cu-1.75Ti填料接合Ti50Ni50合金時,於Ti50Ni50端會出現CuNiTi相及Ti3Cu4相。隨著硬銲時間與溫度的增加,銲道中會生成AlCu2Ti相。而Ti-64端主要的反應相為Ti2Cu、TiCu、Ti3Cu4及TiCu4相。改以Ag-Cu-4.5Ti填料接合時之相演化類似,但由於Ti-Cu介金屬層增厚,剪力值下降且較不穩定。使用BAg-8填料接合鍍Cr、Ni的17-4PH不鏽鋼,於Ti-64端的相演化與前述相似,而17-4PH端的Ni膜消失,Ni元素溶入銲道產生反應,可發現CuNiTi相。使用Ag-Cu-1.75Ti填料接合鍍Cr的17-4PH時,則會於17-4PH端生成TiCr2相,此不利於接點之剪力測試強度。此外,實驗中亦發現鍍有Ni膜時會大幅增進填料潤溼性而使剪力測試數值穩定。使用60Ti-15Cu-25Ni填料接合Ti50Al50合金時,於Ti-64端出現一相當厚的Ti rich相,於Ti50Al50端則有α2-Ti3Al和γ-TiAl的固溶區及連續α2-Ti3Al反應相層,中間的殘留填料區主要為Ti2Cu/Ti2Ni相。改以70Ti-15Cu-15Ni填料接合時相基材兩側生成相相似,而銲道中的殘留填料區較少。使用40Ti-20Zr-20Cu-20Ni填料接合時,由於有Zr元素的參與,兩側基材處的相演化過程產生變化,且銲道中的殘留填料區至少有3種以上不同的相而有待後續的研究。
This research is focused in infrared vacuum brazing Ti-6Al-4V (Ti-64) and other alloys. For the brazed Ti-64 and Ti50Ni50 joint using the Ag-Cu-1.75Ti filler, CuNiTi and Ti3Cu4 are formed adjacent to the Ti50Ni50 substrate, and AlCu2Ti is observed with increasing the brazing time and/or temperature. Ti2Cu, TiCu, Ti3Cu4 and TiCu4 are found nearby the Ti-64 substrate. The microstructural evolution of the joint using the Ag-Cu- 4.5Ti filler is similar to that of Ag-Cu-1.75Ti filler except for thicker Ti-Cu intermetallics. For the brazed Ti-64 and 17-4PH stainless steel (17-4 PH SS) with Cr/Ni coatings joint using the BAg-8 filler, the microstructure of Ti-64 side is similar to the aforementioned result. For the 17-4PH SS side, the Ni film is disappeared and dissolved into the braze resulting in the CuNiTi phase. It is found that introducing a thin layer of Ni film greatly improves the wettibility of the molten braze on the 17-4PH SS, so shear strengths of joints are more stable. For the use of Ag-Cu-1.75Ti filler to braze 17-4PH SS coated with Cr film, TiCr2 is formed next to the 17-4PH SS, and it impairs shear strength of the brazed joint. For the use of 60Ti-15Cu-25Ni filler to braze Ti50Al50 alloy, two layers are formed: one layer composed of α2-Ti3Al and γ-TiAl mixtures and the other having a continuous α2-Ti3Al phase. The residual filler in the brazed zone is composed of Ti2Cu and Ti2Ni. For 70Ti-15Cu-15Ni filler, the microstructural evolution of the joint is very similar to that of 60Ti-15Cu- 25Ni filler except for the decreased residual filler zone. The phase evolution of the joint brazed by 40Ti-20Zr-20Cu- 20Ni filler is changed because of introducing Zr, and there are at least three different phases formed in the residual filler zone.