Zn-Al-Cu-TiB2（ZA27-TiB2） in situ composites were fabricated via reactions between molten aluminum and mixed halide salts（K2TiF6 and KBF4） at temperature of 875 °C. The microstructure, mechanical properties an...Zn-Al-Cu-TiB2（ZA27-TiB2） in situ composites were fabricated via reactions between molten aluminum and mixed halide salts（K2TiF6 and KBF4） at temperature of 875 °C. The microstructure, mechanical properties and wear behavior of the composites were investigated. Microstructure analysis shows that fine and clean TiB2 particles distribute uniformly through the matrix. The mechanical properties of the composites increase with the increase in TiB2 content. As TiB2 content increases to 5%（mass fraction）, an improvement of HB 18 in hardness and 49 MPa in ultimate tensile strength（UTS） is achieved. The overall results reveal that the composites possess low friction coefficients and the wear rate is reduced from 5.9×10-3 to 1.3×10-3 mm3/m after incorporating 5% TiB2. Friction coefficient and worn surface analysis indicate that there is a change in the wear mechanism in the initial stage of wear test after introducing in situ TiB2 particles into the matrix.展开更多
Apophyseal injuries of the pelvis have increased recently with increased participation of teenagers in contact sports. Apophyseal fractures of the pelvis should be ruled out from apophysitis, os acetabuli and bony tum...Apophyseal injuries of the pelvis have increased recently with increased participation of teenagers in contact sports. Apophyseal fractures of the pelvis should be ruled out from apophysitis, os acetabuli and bony tumors. We report a case of fracture of anterior-inferior iliac spine following indirect injury to the hip in a young football player. The patient failed to get better with nonoperative management and continued to have pain in the left hip and signs and symptoms of impingement. He improved following surgical excision of the heterotopic bone and did not have any evidence of recurrence at 2 years followup.展开更多
基金Projects(51071035,51274054,51375070)supported by the National Natural Science Foundation of ChinaProject(313011)supported by the Key Project of Ministry of Education of China
文摘Zn-Al-Cu-TiB2（ZA27-TiB2） in situ composites were fabricated via reactions between molten aluminum and mixed halide salts（K2TiF6 and KBF4） at temperature of 875 °C. The microstructure, mechanical properties and wear behavior of the composites were investigated. Microstructure analysis shows that fine and clean TiB2 particles distribute uniformly through the matrix. The mechanical properties of the composites increase with the increase in TiB2 content. As TiB2 content increases to 5%（mass fraction）, an improvement of HB 18 in hardness and 49 MPa in ultimate tensile strength（UTS） is achieved. The overall results reveal that the composites possess low friction coefficients and the wear rate is reduced from 5.9×10-3 to 1.3×10-3 mm3/m after incorporating 5% TiB2. Friction coefficient and worn surface analysis indicate that there is a change in the wear mechanism in the initial stage of wear test after introducing in situ TiB2 particles into the matrix.
文摘Apophyseal injuries of the pelvis have increased recently with increased participation of teenagers in contact sports. Apophyseal fractures of the pelvis should be ruled out from apophysitis, os acetabuli and bony tumors. We report a case of fracture of anterior-inferior iliac spine following indirect injury to the hip in a young football player. The patient failed to get better with nonoperative management and continued to have pain in the left hip and signs and symptoms of impingement. He improved following surgical excision of the heterotopic bone and did not have any evidence of recurrence at 2 years followup.
