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performance. As an effective deformation technique, hot porthole die extrusion has been widely used to fabricate Al alloy hollow profiles. Longitudinal weld seam is a typical feature of porthole die extrusion... was assumed at the interfaces of the billet and tools. 1/8 of the numerical simulation model was set up for reducing the total computational time, owing to the symmetries of dies and deformation, as shown......
properties of the alloy fabricated by semi-solid die casting can be improved[15]. 4.2 Evolution mechanism of α-particles in thixo- diecasting The semi-solid deformation behaviors of solid particles... deformation of solid particles(PDS). During thixo-diecasting, the filling of semi-solid alloy slurry belongs to complicated two-phase flows, in which the flows include not only the absolute flowing of solid......
. The fluid pressure acting on blank makes the deformation more complex. Because of the low plasticity and formability of aluminum alloy, it is easier to crack in the HDD process. Many process parameters influence the HDD process, such as die cavity pressure, blank holder force and pre-bulging. But the most important one is the pre-bulging. The pre-bulging deformation is extraordinarily uneven in the HDD......
, the ductility and formability are poor at room temperature and magnesium alloy applications are restricted. The grain refinement is an important way to improve the deformation capacity [3], so the grain... that the plasticity of AZ31B magnesium alloy at room temperature is significantly improved, so the deformation ability is advanced to a large extent. Table 2 Tensile properties of of AZ31B magnesium alloy Fig......
; 文献标志码:A Dynamic recrystallization behaviors of twin-roll cast AZ31 magnesium alloy during high temperature tensile deformation SHI Guo-dong1, QIAO Jun2, HE Min2, ZHANG... alloy with nonequilibrium grain boundaries[J]. Acta Materialia, 1999, 47(7): 2047-2057. [3] KIM W J, CHUNG S W, CHUNG C S, KUM D. Superplasticity in thin magnesium alloy sheets and deformation mechanism......
material was composed of regular hexagonal crystal grains and the grain unit was connected by the grain boundary unit accounting for shear deformation between grains. This approach was also introduced... deformation mechanism and material flow behavior. In this work, micro-sheet metal is taken as the research object; Hall-Petch equation, a traditional polycrystalline material model, based on the surface......
态压缩后不同部位的显微组织 Fig. 4 Microstructures at different positions after deformation 同时,由图3(d)还发现,当变形速率为10 s-1时,曲线的下降趋势稍微不同于其他曲线.这是由于应变速率较大时,孔洞的形成跟不上形变过程,即裂纹的扩展跟不上形变.此时变形接近固相变形过程,所以在压缩过程中流变应力下降趋势变缓,基本上... Original data of stress, strain , strain rate and temperature t 表2 非线性回归系数 Table 2 Nonlinear regression coefficients 图6 流变应力实验值与计算值的关系 Fig. 6 Correlation......
α-solid and Cu2Te phases. The microstructure of hot-rolled copper alloy with the deformation rate of 70% is shown in Fig. 1(b). The microstructure is obviously refined as the coarse column grain... in the matrix. A fiber structure of cold-rolled copper alloy with the deformation rate of 70% shown in Fig. 1(c) is a typical work-hardened structure with a large number of slip bands and blurred grain......
of nickel based single crystal superalloys only at intermediate temperatures or at high temperature [10-13], few references report that the creep feature and deformation mechanisms of the alloys from medial... faults form within the γ′ phase. Super lattice intrinsic stacking faults (SISFs) are the major features of the deformation microstructure of single crystal superalloys at this condition. The high density......
deformation[J]. Progression Materials Science, 2000, 45: 103-189. [4] 郭廷彪, 丁雨田, 胡 勇, 曹 军, 李更新. 等通道转角挤压(ECAP)工艺的研究进展[J]. 兰州理工大学学报, 2009, 34(6): 20-20. GUO Ting-biao, DING Yu-tian, HU Yong, CAO Jun, LI Geng-xin. Research progressing of technology of equal-channel angular pressing(ECAP)[J]. 兰州理工大学学报, 2009, 34(6): 20-20. [5] WANG C, LI F, CHEN B, YUAN Z, LU H. Severe plastic deformation techniques......