A novel melting infiltration by ultrasonic vibration was investigated and applied to fabricate Ti6Al4V(TC4)lattice structure-reinforced Mg-10Gd-2Y-1Zn-xZr(refer to VW92 hereafter,x=0,0.5 wt%)alloy matrix composites.Th...A novel melting infiltration by ultrasonic vibration was investigated and applied to fabricate Ti6Al4V(TC4)lattice structure-reinforced Mg-10Gd-2Y-1Zn-xZr(refer to VW92 hereafter,x=0,0.5 wt%)alloy matrix composites.The edge-to-edge matching model indicates that the well-matching and possible orientation relationships(ORs)between theα-Mg andα-Ti,[10-10]_(α-Mg)//[11-23]_(α-Ti) in(0002)_(α-Mg)//(10-10)_(α-Ti) possesses the smallest misfit of 0.4%(f_(r)),and thus theα-Mg grains can nucleate on the TC4 lattice structure.Interfacial reaction occurred in the TC4/VW92+0.5 wt%Zr composites,and the reaction product was confirmed to be Al_(2)Zr_(3),AlZr_(2) andα-Ti(Zr)particles formed by continuous solution of Zr-Ti.Among the interfacial products,the AlZr_(2) phase is a brittle phase with high-volume fraction,which is not conducive to the load transfer.But generally speaking,theα-Ti(Zr)and theα-Mg tend to form a coherent interface,which is beneficial for improving the interfacial bonding strength of composites.展开更多
Mg-Gd-Y-Zr alloy castings are widely used in the aerospace field owing to their high strength and excellent creep resistance.The castability of these alloys is also an important consideration for engineering applicati...Mg-Gd-Y-Zr alloy castings are widely used in the aerospace field owing to their high strength and excellent creep resistance.The castability of these alloys is also an important consideration for engineering application.Thus,the hot tearing susceptibilities(HTSs)of Mg-10Gd-1Y-1Zn-0.5Zr(VW91)alloy and Mg-10Gd-2Y-1Zn-0.5Zr(VW92)alloy are investigated with a constrained rod casting(CRC)mold.The microstructures and fracture surface are characterized by optical microscope and scanning electron microscope.The results unveil that the HTS of VW92alloy is lower than that of VW91 alloy.The microstructures indicate that obvious tears can be observed in VW91 alloy,while the tears in VW92 alloy are tiny.The tear feeding and healing by eutectic are also observed in VW91 and VW92alloys.Therefore,the lower hot tearing susceptibility of VW92 alloy is mainly attributed to the high amount of eutectic which feeds and heals tears.Besides,the effects of the coefficient of thermal expansion(CTE)and the fluidity of VW91 and VW92 alloys on their HTSs are discussed.展开更多
基金supported by the Guangdong Major Project of Basic and Applied Basic Research (2020B0301030006)the National Natural Science Foundation of China (52225101)+2 种基金the Scientific Research Foundation of Chongqing University of Technology (2020ZDZ006)the Science and Technology Research Program of the Chongqing Municipal Education Commission (KJZD-K202201108)the University Innovation Research Group of Chongqing (CXQT20023).
文摘A novel melting infiltration by ultrasonic vibration was investigated and applied to fabricate Ti6Al4V(TC4)lattice structure-reinforced Mg-10Gd-2Y-1Zn-xZr(refer to VW92 hereafter,x=0,0.5 wt%)alloy matrix composites.The edge-to-edge matching model indicates that the well-matching and possible orientation relationships(ORs)between theα-Mg andα-Ti,[10-10]_(α-Mg)//[11-23]_(α-Ti) in(0002)_(α-Mg)//(10-10)_(α-Ti) possesses the smallest misfit of 0.4%(f_(r)),and thus theα-Mg grains can nucleate on the TC4 lattice structure.Interfacial reaction occurred in the TC4/VW92+0.5 wt%Zr composites,and the reaction product was confirmed to be Al_(2)Zr_(3),AlZr_(2) andα-Ti(Zr)particles formed by continuous solution of Zr-Ti.Among the interfacial products,the AlZr_(2) phase is a brittle phase with high-volume fraction,which is not conducive to the load transfer.But generally speaking,theα-Ti(Zr)and theα-Mg tend to form a coherent interface,which is beneficial for improving the interfacial bonding strength of composites.
基金the Key Research and Development Program of Zhejiang of China(No.2021C01086)the National Natural Science Foundation of China(No.52071036)the Interdisciplinary and Team Building Program of Central Universities,China(No.2020CDJQY-A002,2021CDJCGJ009)。
文摘Mg-Gd-Y-Zr alloy castings are widely used in the aerospace field owing to their high strength and excellent creep resistance.The castability of these alloys is also an important consideration for engineering application.Thus,the hot tearing susceptibilities(HTSs)of Mg-10Gd-1Y-1Zn-0.5Zr(VW91)alloy and Mg-10Gd-2Y-1Zn-0.5Zr(VW92)alloy are investigated with a constrained rod casting(CRC)mold.The microstructures and fracture surface are characterized by optical microscope and scanning electron microscope.The results unveil that the HTS of VW92alloy is lower than that of VW91 alloy.The microstructures indicate that obvious tears can be observed in VW91 alloy,while the tears in VW92 alloy are tiny.The tear feeding and healing by eutectic are also observed in VW91 and VW92alloys.Therefore,the lower hot tearing susceptibility of VW92 alloy is mainly attributed to the high amount of eutectic which feeds and heals tears.Besides,the effects of the coefficient of thermal expansion(CTE)and the fluidity of VW91 and VW92 alloys on their HTSs are discussed.
