Equal channel angular pressing （ECAP） processing and annealing were applied to the AZ31 magnesium alloy sheets to evaluate the potential improvement in the mechanical properties and formability. The ECAP experiment ...Equal channel angular pressing （ECAP） processing and annealing were applied to the AZ31 magnesium alloy sheets to evaluate the potential improvement in the mechanical properties and formability. The ECAP experiment was conducted at 300 ℃ in a die having an included angle of 90o between two channels by the BCZ route with the sheets rotated by 90°about the normal axis of plate plane. The tensile tests and conical cup tests were conducted at various temperatures from 20 to 250 ℃. The experimental results indicated that improving the working temperatures could lead to the soft in the material and the enhancement of ductility. Comparatively, the ECAPed AZ31 alloy sheets showed the lower yield strength and smaller conical cup value （CCV） than the unECAPed counterpart in the room temperature. The difference in yield strength between them became small in the elevated temperature, but the ECAPed samples still had the smaller CCV value, implying the improved formability. The texture of the AZ31 alloy sheets could be modified by ECAP and the decrease in the yield strength and more uniform deformation realized in the material, so the formability of AZ31 alloy sheets was improved.展开更多
文摘Equal channel angular pressing （ECAP） processing and annealing were applied to the AZ31 magnesium alloy sheets to evaluate the potential improvement in the mechanical properties and formability. The ECAP experiment was conducted at 300 ℃ in a die having an included angle of 90o between two channels by the BCZ route with the sheets rotated by 90°about the normal axis of plate plane. The tensile tests and conical cup tests were conducted at various temperatures from 20 to 250 ℃. The experimental results indicated that improving the working temperatures could lead to the soft in the material and the enhancement of ductility. Comparatively, the ECAPed AZ31 alloy sheets showed the lower yield strength and smaller conical cup value （CCV） than the unECAPed counterpart in the room temperature. The difference in yield strength between them became small in the elevated temperature, but the ECAPed samples still had the smaller CCV value, implying the improved formability. The texture of the AZ31 alloy sheets could be modified by ECAP and the decrease in the yield strength and more uniform deformation realized in the material, so the formability of AZ31 alloy sheets was improved.
文摘临床生化检验的运行过程实际包含了各种可波动的误差因素，实施质量控制时，应该遵照循证医学（Evidencebased medicine，EBM）的基本理论，遵循质量控制的证据；按照生化检验的循证质量控制公式ASEc=CCV／CV，来表达实验室内部与外部质量管理（即室内质控IQC与室间质评EQA）、个体质量变异与总体质量变异（即CV与CCV）相互之间联系又制约的规律性，是生化检验循证质量控制（Evidence—based of Quality Control，EBQC）要获取重要证据的必然途径。
