Polycrystalline ZrO2-3 mol.%Y2O3 was brazed to Ti-6Al-4V by using a Ti47Zr28Cu14Ni11（at.%） amorphous ribbon at 1123–1273 K in a high vacuum. The influences of brazing temperature on the microstructure and shear str...Polycrystalline ZrO2-3 mol.%Y2O3 was brazed to Ti-6Al-4V by using a Ti47Zr28Cu14Ni11（at.%） amorphous ribbon at 1123–1273 K in a high vacuum. The influences of brazing temperature on the microstructure and shear strength of the joints were investigated. The interfacial microstructures can be described as ZrO2/TiO＋TiO2＋Cu2Ti4O＋Ni2Ti4O/α-Ti＋（Ti,Zr）2（Cu,Ni） eutectic/acicular Widmanst¨aten structure/Ti–6Al–4V alloy. With the increase in the brazing temperature, the thickness of the TiO＋TiO2＋Cu2Ti4O＋Ni2Ti4O layer reduced, the content of the α-Ti＋（Ti,Zr）2（Cu,Ni） eutectic phase decreased, while that of the coarse α-Ti phase gradually increased. The shear strength of the joints did not show a close relationship with the thickness of the TiO＋TiO2＋Cu2Ti4O＋Ni2Ti4O layer. However, when the coarse （Ti,Zr）2（Cu,Ni） phase was non-uniformly distributed in the α-Ti phase, or when α-Ti solely situated at the center of the joint, forming a coarse block or even connecting into a continuous strip, the shear strength greatly decreased.展开更多
In the present study, laser alloying of electroless Nie P coating on aluminum substrate was conducted using Nd：YAG pulsed laser under the condition of 5.36 109W/m2 in power density and 3.0 mm/s in scanning speed. The...In the present study, laser alloying of electroless Nie P coating on aluminum substrate was conducted using Nd：YAG pulsed laser under the condition of 5.36 109W/m2 in power density and 3.0 mm/s in scanning speed. The rapidly solidified microstructure in the alloyed layer was studied. The results showed that the alloying element distributed in the alloyed layer is inhomogeneous. The dendrite containing relatively high Ni was identified as Al3Ni phase and the areas between the dendrites are rich in Al content. Featureless with cell structure in Al-rich areas was firstly displayed by z-contrast image. Amorphous structure was revealed to exist in Al-rich areas.展开更多
A commercially available Ti47Zr2sCu14Nin （at. pct） amorphous filler foil was used to join ZrO2 ceramic and Ti-6A1-4V alloy. According to experimental observations, the interface microstructure accounts for the mecha...A commercially available Ti47Zr2sCu14Nin （at. pct） amorphous filler foil was used to join ZrO2 ceramic and Ti-6A1-4V alloy. According to experimental observations, the interface microstructure accounts for the mechanical properties of the joints. The effects of brazing conditions and parameters on the joint properties were investigated. The joint shear strength showed the highest value of about 108 MPa and did not monotonously increase with the brazing time increasing. It was shown that decreasing of brazing cooling rate and appropriate filler foil thickness gave higher joint strength.展开更多
基金supported by 2009 Open Foundation of the Key Lab of Automobile Materials, Jilin University,from Natural Scientific Basic Research Fund for Platform and Base Construction (Grant No. 09-421060352467)the Department of Science & Technology of Jilin Province (Grant No. 20100545)
文摘Polycrystalline ZrO2-3 mol.%Y2O3 was brazed to Ti-6Al-4V by using a Ti47Zr28Cu14Ni11（at.%） amorphous ribbon at 1123–1273 K in a high vacuum. The influences of brazing temperature on the microstructure and shear strength of the joints were investigated. The interfacial microstructures can be described as ZrO2/TiO＋TiO2＋Cu2Ti4O＋Ni2Ti4O/α-Ti＋（Ti,Zr）2（Cu,Ni） eutectic/acicular Widmanst¨aten structure/Ti–6Al–4V alloy. With the increase in the brazing temperature, the thickness of the TiO＋TiO2＋Cu2Ti4O＋Ni2Ti4O layer reduced, the content of the α-Ti＋（Ti,Zr）2（Cu,Ni） eutectic phase decreased, while that of the coarse α-Ti phase gradually increased. The shear strength of the joints did not show a close relationship with the thickness of the TiO＋TiO2＋Cu2Ti4O＋Ni2Ti4O layer. However, when the coarse （Ti,Zr）2（Cu,Ni） phase was non-uniformly distributed in the α-Ti phase, or when α-Ti solely situated at the center of the joint, forming a coarse block or even connecting into a continuous strip, the shear strength greatly decreased.
文摘In the present study, laser alloying of electroless Nie P coating on aluminum substrate was conducted using Nd：YAG pulsed laser under the condition of 5.36 109W/m2 in power density and 3.0 mm/s in scanning speed. The rapidly solidified microstructure in the alloyed layer was studied. The results showed that the alloying element distributed in the alloyed layer is inhomogeneous. The dendrite containing relatively high Ni was identified as Al3Ni phase and the areas between the dendrites are rich in Al content. Featureless with cell structure in Al-rich areas was firstly displayed by z-contrast image. Amorphous structure was revealed to exist in Al-rich areas.
基金supported by 2009 Open Foundation of the Key Lab of Automobile Materials, Jilin University, from Natural Scientific Basic Research Fund for Platform and Base Construction (Grant No. 09-421060352467)the Depart-ment of Science & Technology of Jilin Province of China (Grant No. 20100545)
文摘A commercially available Ti47Zr2sCu14Nin （at. pct） amorphous filler foil was used to join ZrO2 ceramic and Ti-6A1-4V alloy. According to experimental observations, the interface microstructure accounts for the mechanical properties of the joints. The effects of brazing conditions and parameters on the joint properties were investigated. The joint shear strength showed the highest value of about 108 MPa and did not monotonously increase with the brazing time increasing. It was shown that decreasing of brazing cooling rate and appropriate filler foil thickness gave higher joint strength.
