This study examines the grain characteristics,dynamic precipitation phase characteristics,and texture evolution of Mg-Ga-xZn alloys produced through medium-high strain rate rolling.It investigates the impact of Zn on ...This study examines the grain characteristics,dynamic precipitation phase characteristics,and texture evolution of Mg-Ga-xZn alloys produced through medium-high strain rate rolling.It investigates the impact of Zn on the mechanical and damping properties of Mg-Ga sheet.The addition of Zn reduces the solid solubility of Ga inα-Mg,facilitating dynamic precipitation,grain refinement,and weakening of the basal texture of the sheet,ultimately enhancing strength and damping performance.The yield strength of the sheet initially increases and then decreases with increasing Zn content.The Mg-5Ga-0.6 Zn alloy demonstrates the best overall mechanical properties,with a yield strength,tensile strength,and elongation of 221 MPa,304 MPa,and 28.6%,respectively,primarily attributed to fine-grained strengthening.Damping performance at low strain amplitudes also follows a similar trend with increasing Zn content,with Mg-5Ga-0.6 Zn showing the highest damping values.The study suggests that the decrease in damping performance due to Zn can be linked to the reduced solid solubility of Ga inα-Mg.Specifically,at a strain amplitude of 1×10^(-3),the damping values Q-1 of Mg-5Ga,Mg-5Ga-0.6 Zn,and Mg-5Ga-1.2 Zn alloy sheets are 0.0167,0.0152,and 0.0174,respectively.These findings have implications for the development of bio-implantable magnesium alloys with high damping properties.展开更多
The flux cored wires with different rare earth oxide additions for hardfacing the workpieces of medium-high carbon steel were developed. The microstrucmre of the hardfacing layer was observed using the optical microsc...The flux cored wires with different rare earth oxide additions for hardfacing the workpieces of medium-high carbon steel were developed. The microstrucmre of the hardfacing layer was observed using the optical microscopy. The average dimension of primary austenite grains in hardfacing layer was measured by image analyzer. The primary austenite grain growth activation energy and index were calculated according to Sellars＇s mode and Beck formula, respectively. Moreover, the effect of rare earth oxide on the growth dynamics of primary aus- tenite grain was analyzed, and then discussed with the misfit theory. The experimental results showed that, by adding rare earth oxide, the av- erage dimension of primary austenite grains in hardfacing layer of medium-high carbon steel decreased, and it was the smallest when the ad- dition of rare earth oxide was 5.17 wt.%. Meanwhile, at this rare earth oxide addition, the primary austenite grain growth activating energy in hardfacing layer was the largest, while its index was the smallest. The calculated results indicated that the primary austenite grain could be refined because LaAlO3 as heterogeneous nuclei of γ-Fe was the most effective.展开更多
The Wugong Mts. region may have experienced three stages of metamorphism in Early Paleo-zoic, which may be closely related to the generations of regional deformation. The first stage ismedium-pressure metamorphism, th...The Wugong Mts. region may have experienced three stages of metamorphism in Early Paleo-zoic, which may be closely related to the generations of regional deformation. The first stage ismedium-pressure metamorphism, the second medium- and high-pressure one with stress on high-pressure metamorphism, and the third low-pressure and high-temperature metamorphism. Theregion, as a whole, is a Caledonian medium-high pressure metamorphic belt.展开更多
基金supported by National Natural Science Foundation of China(Grant No.51871093)the Scientific Research Program for Introducing Talents of Guizhou University(No.2023(06))the Basic Research Program of Guizhou University(No.2023(02)).
文摘This study examines the grain characteristics,dynamic precipitation phase characteristics,and texture evolution of Mg-Ga-xZn alloys produced through medium-high strain rate rolling.It investigates the impact of Zn on the mechanical and damping properties of Mg-Ga sheet.The addition of Zn reduces the solid solubility of Ga inα-Mg,facilitating dynamic precipitation,grain refinement,and weakening of the basal texture of the sheet,ultimately enhancing strength and damping performance.The yield strength of the sheet initially increases and then decreases with increasing Zn content.The Mg-5Ga-0.6 Zn alloy demonstrates the best overall mechanical properties,with a yield strength,tensile strength,and elongation of 221 MPa,304 MPa,and 28.6%,respectively,primarily attributed to fine-grained strengthening.Damping performance at low strain amplitudes also follows a similar trend with increasing Zn content,with Mg-5Ga-0.6 Zn showing the highest damping values.The study suggests that the decrease in damping performance due to Zn can be linked to the reduced solid solubility of Ga inα-Mg.Specifically,at a strain amplitude of 1×10^(-3),the damping values Q-1 of Mg-5Ga,Mg-5Ga-0.6 Zn,and Mg-5Ga-1.2 Zn alloy sheets are 0.0167,0.0152,and 0.0174,respectively.These findings have implications for the development of bio-implantable magnesium alloys with high damping properties.
基金Program supported by National Nature Science Foundation of China(51271163)Key Project of Science and Technology of Hebei Province(09215106D)
文摘The flux cored wires with different rare earth oxide additions for hardfacing the workpieces of medium-high carbon steel were developed. The microstrucmre of the hardfacing layer was observed using the optical microscopy. The average dimension of primary austenite grains in hardfacing layer was measured by image analyzer. The primary austenite grain growth activation energy and index were calculated according to Sellars＇s mode and Beck formula, respectively. Moreover, the effect of rare earth oxide on the growth dynamics of primary aus- tenite grain was analyzed, and then discussed with the misfit theory. The experimental results showed that, by adding rare earth oxide, the av- erage dimension of primary austenite grains in hardfacing layer of medium-high carbon steel decreased, and it was the smallest when the ad- dition of rare earth oxide was 5.17 wt.%. Meanwhile, at this rare earth oxide addition, the primary austenite grain growth activating energy in hardfacing layer was the largest, while its index was the smallest. The calculated results indicated that the primary austenite grain could be refined because LaAlO3 as heterogeneous nuclei of γ-Fe was the most effective.
文摘The Wugong Mts. region may have experienced three stages of metamorphism in Early Paleo-zoic, which may be closely related to the generations of regional deformation. The first stage ismedium-pressure metamorphism, the second medium- and high-pressure one with stress on high-pressure metamorphism, and the third low-pressure and high-temperature metamorphism. Theregion, as a whole, is a Caledonian medium-high pressure metamorphic belt.
