共搜索到2673条信息，每页显示10条信息，共268页。用时：0小时0分0秒407毫秒
Trans. Nonferrous Met. Soc. China 22(2012) s376-s381 Effect of internal pressure on corner radius and thickness distribution of shear hydro-bending of 5A02 aluminum alloy tube WANG Yong, HAN Cong... of internal pressure on forming defects, corner radius and thickness distribution of 5A02 aluminum alloy shear hydro-bending tubes were studied by experiment. Numerical simulation was conducted......
超声振动对SCN-3%ETH模拟合金定向凝固的影响段萌萌1,陈长乐1(1.陕西省西安市西北工业大学理学院陕西省凝聚态结构与性质重点实验室)摘 要:研究了27.5 kHz高频超声振动下SCN-3%ETH(Succinonitrile-3%ethanol,质量分数)模拟合金的定向凝固过程.结果表明,超声作用时界面出现钝化,曲率半径随超声作用时间的增加不断增大;撤去超声振动后,界面上形成被细化的胞晶组织;由于空化效应产生的瞬时高温高压的冲击破坏和声流的搅拌作用以及强迫振动的剪切作用,部分枝晶尖端断裂;界面生长速度随超......
Trans. Nonferrous Met. Soc. China 26(2016) 2170-2178 Determination of processing power and optimum billet radius of modified backward extrusion by upper bound approach S. H. HOSSEINI, K. ABRINIA... with extrusion force and dissipated powers were shown. Finding the initial billet size, a challenging area in the modified backward extrusion method, was discussed and the optimum billet radius......
......
with different components were prepared, the influencing factors (the comprehensive atomic radius difference δ, the mixing enthalpy △H and the mixing entropy △S) of phase composition of the alloys... entropy alloys. Key words: high entropy alloy; solid solution; comprehensive atomic radius difference; mixing enthalpy; formation condition 1 Introduction The design criterion of traditional alloys has......
in the rock mass, rock mass sliding surface was verified with the variational method. On the assumption that rock mass was elastic-perfectly plastic material, rock mass critical radius came out in plastic... parameter on the tunnel plastic radius and safety factor were analyzed. The results show that enhancing rock mass cohesion, friction angel and support are able to restrain the development of tunnel plastic......
......
. The radius of influence was investigated by using electrical resistance tomography, the removal efficiency of benzene and xylene was studied by using air sparging (AS) technique in heterogeneous soil... in the process. Key words: air sparging; petroleum contaminated; ground water; electrical resistance tomography; radius of influence; heterogeneous soil 空气曝气法(AS)是一种原位修复技术,被认为是去除饱和区土壤和地下水中挥发性和半挥发性有机化合物的经济有效的方法[1-3......
, and a new concept of neutral layer offset radius ratio was also put forward. Finally, the calculation model of bar straightening springback deflection combined with the pure bending springback theory... words: bar straightening; neutral layer offset radius ratio; springback model; experimental analysis 随着石油,船舶,汽车等制造行业的飞速发展,对高强度合金钢棒材的需求量和质量要求日益提高,其中直线度要求达到1 mm/m,甚至小于0.5 mm/m,否则后续加工中材料的去除量非常大,损耗严重,成本急剧增加......
综合考虑了纵向蠕滑力,横向蠕滑力,轮轨法向力,接触斑和材料纯剪切屈服强度对轮轨滚动接触疲劳的影响,其表达式为 (1) 式中:为接触斑纵向蠕滑力,N；为接触斑横向蠕滑力,N；为轮轨法向力,N；a和b分别为椭圆接触斑的短半轴和长半轴,mm；k为材料纯剪切屈服强度,取303 MPa. 如果计算得到的大于0,则认为轮轨材料可能发生棘轮效应,塑性变形会持续累积直至材料失去韧性而发生疲劳裂纹.由式(1)可知:牵引力系数增大或接触斑面积减小,会导致表面疲劳指数增大[14]. 1.2.2 轮轨磨耗与滚动接触疲劳的耦合关系 为更好地理解和描述滚动疲劳裂纹生长的每个阶段,英国铁路安全和标准委员会(RSSB)于2......
