本研究利用紅外線快速加熱,以Cusil-ABA(63Ag-35.25Cu-1.75Ti wt.%)銀基填料硬銲異質接合CP-Ti與Ti50Ni50形狀記憶合金,並對潤濕性、顯微組織及接點之剪力強度進行研究。以Cusil-ABA填料於850℃接合CP-Ti與Ti50Ni50時,在CP-Ti介面處會生成一系列的Cu-Ti介金屬相,填料中的Cu會擴散進入CP-Ti並形成一層α-Ti與CuTi2的共析組織,其層厚隨持溫時間拉長而增加;在Ti50Ni50介面處會產生(CuxNi1-x)2Ti相;破壞主要沿著銲道中央之Ag-rich相與Cu4Ti3相延伸,屬於延脆性混合破壞;將持溫溫度提升至900℃,填料中的Ag-rich相會大量溢出銲道,破壞主要沿著銲道內之CuTi2相延伸,屬於脆性破壞。本研究同時以40Ti-20Zr-20Cu-20Ni(wt.%)及70Ti-15Cu-15Ni(wt.%)兩種鈦基填料硬銲異質接合Ti-15-3合金與Ti50Ni50。以40Ti-20Zr-20Cu-20Ni填料接合時,銲道中生成Ti2Ni相、β-Ti相及填料元素在高溫互溶後冷卻凝固所得的相,持溫時間或溫度之增加皆會使兩側基材受到填料侵蝕而導致銲道變寬,且不連續的Ti2Ni相漸變為連續,因破壞產生於Ti2Ni相,故此時接點之剪力強度隨之下降,並屬於脆性破壞。而以70Ti-15Cu-15N填料接合時,銲道中主要為Ti2Ni相,其中零星分佈β-Ti相及 Ti50Ni50基材受填料侵蝕而溶入銲道所生成的相,破壞產生於的Ti2Ni相,拉長持溫時間會使β-Ti相及Ti50Ni50基材受到填料侵蝕而溶入銲道所生成的相逐漸消失,使得裂痕延伸時遇到的阻礙較少,故接點之剪力強度隨之下降,並屬於脆性破壞。
Wetting behavior、microstructural evolution and bonding strength of infrared brazed Ti50Ni50/CP-Ti using Cusil-ABA filler are studied. For brazing at 850℃, many interfacial layers are observed including α-Ti/Ti2Cu eutectoid, Ti2Cu, TiCu, Ti3Cu4, TiCu4, Ag-rich matrix and (CuxNi1-x)2Ti layers. Raising the brazing time and temperature let Cu atoms have enough time to diffuse into CP-Ti, so α-Ti/Ti2Cu eutectoid layer will become thicker. The shear tests indicate the brazed joint is mainly fractured along the Ti3Cu4 layer and central Ag-rich matrix in which the fracture surface exhibits ductile/brittle mixing mode. For brazing at 900℃, Ag-rich phase is expelled from braze and the brazed joint is full of intermetallic phases which change the fracture mode to brittle one. For using 40Ti-20Zr-20Cu-20Ni filler infrared bazed Ti-15-3 alloy and Ti50Ni50, Ti2Ni, β-Ti and residual filler are formed in the braze. During the shear tests, the crack forms in the Ti2Ni phase and then propagates until the sample is fractured. The higher the brazing temperature is or the longer the brazing time is, the more the continuous Ti2Ni will be. Therefore, the shear strength of the brazed joint decreases with increasing the brazing time or temperature. When using 70Ti-15Cu-15Ni filler brazed Ti-15-3/Ti50Ni50, Ti2Ni, β-Ti and dissolved Ti50Ni50 are formed in the braze. The shear tests show the crack is also formed in the Ti2Ni phase and the fracture surface exhibits brittle mode. The amount of Ti2Ni phase increases and that of β-Ti and dissolved Ti50Ni50 decreases with increasing the brazing time and temperature, and thus the shear strength of the brazed joint decreases simultaneously.