稀土镁对高硼铁基合金的影响

高硼铁基合金是一种新型的耐磨材料,其特点是以组织中硬脆的共晶硼化物作为材料的耐磨相。但是,由于共晶硼化物在晶界处呈网状分布,破坏了基体的连续性,导致材料韧性偏低。提高该种材料韧性的有效途径便是改善硼化物的形态,文中采用稀土镁对高硼铁基合金进行变质,在热处理条件下,改善了硼化物的形态,将材料的冲击韧度提高了34.6%。     

碘化钛的电子束熔炼提纯效果分析

通过对碘化钛电子束熔炼提纯效果分析，提出合理、经济的高纯钛制取工艺路线。     

钇基重稀土镁复合球化剂在铸态高韧性厚壁球铁件上的应用

应用钇基重稀土镁复合球化剂，铸造厚大断面高韧性球铁冷却壁，成功地获得了铸件中心部位铸态高性能。超过了用户要求和美国ＡＣ公司的标准。铸件中心部位铸态延伸率≥１７％，接近了铸件外层或附铸试块的水平。     

核电工程材料的应力腐蚀破裂研究

采用慢应变速率试验(SSRT)和U型弯曲试验技术研究了水中杂质离子、溶解氧(DO)、外加电位以及温度等对核电工程材料304不锈钢(SS)、316SS以及A533B压力容器用钢在高温水中应力腐蚀破裂(SCC)的影响,并结合电化学测试和表面膜分析结果进行了讨论,还根据304SS的U型弯曲和SSRT结果的差异提出了SCC加速试验的选择原则建议。     

HIGH RESOLUTION STUDY OF TWINS IN Al_(20)Cu_2Mn_3 PHASE

The dispersoid phase Al_(20)Cu_2Mn_3 in a 2024 Al alloy is commonly composed of twins,An ob-servation of corresponding high resolution image shows that the twin boundary plane is a glideplane other than mirror one.Two neighbouring components of twins are not symmetry of re-flection or rotation,but of glide reflection.The“diamond”glide plane is(101)and the glidevector is(1/4)(-).Components of twins in the phase take shape of prism with thelongitudinal edge being parallel to[010]and side faces being{101}and{100}.     

Calculation of temperature field near stagnation point in explosive welding

0IntroductionResearch of temperature field near stagnation pointquantificationally is of great importance to control the qual-ity of explosive welding. If the temperature at the weldinginterface is too high the material will melt in excess andthe metal plates can not be welded well and if the tempera-ture is too lowthe plates can not be well-knit. At the sametime to calculate the heat behavior in the flow field of ex-plosive welding quantificationally is the basis to analyze themetallurgic eff…     

Numerical simulation of deep cryogenic treatment electrode tip temperature for spot welding aluminum alloy

Deep cryogenic treatment technology of electrodes is put forward to improve electrode life of resistance spot welding of aluminum alloy LF2.Deep cryogenic treatment makes electrode life for spot welding aluminum alloy improve.The specific resistivity of the deep cryogenic treatment electrodes is tested and experimental results show that specific resistivity is decreased sharply.The temperature field and the influence of deep cryogenic treatment on the electrode tip temperature during spot welding aluminium alloy is studied by numerical simulation method with the software ANSYS.The axisymmetric finite element model of mechanical,thermal and electrical coupled analysis of spot welding process is developed.The numerical simulation results show that the influence of deep cryogenic treatment on electrode tip temperature is very large.     

高强度Al-Sn-Si-Cu-Mg轴瓦材料的研究

针对现代发动机向高速、重载、无污染方向发展的需求，研发出了一种新型高承载能力的、无Pb的铝合金轴瓦材料。通过正交试验，分析了添加元素对合金力学性能的影响规律，确定了合金的成分控制范围。试验结果表明：该合金具有显著的时效硬化能力，它在475℃ 0．5h固溶淬火、160℃8h时效后的性能指标可达HV≥70；抗拉强度Rm≥200N／mm^2；伸长率A≥15％。     

均匀设计法、神经网络和遗传算法结合在内高压成形工艺参数优化中的应用

内高压成形技术是以轻量化和一体化为特征的一种空心变截面轻体构件的先进制造技术。目前,内高压成形技术越来越受到人们的关注,特别是汽车制造企业。管材的内高压成形过程与很多因素有关,其中施加在管件内部的压力与轴向进给量之间的配比关系尤为重要,对两者的匹配关系进行优化是内高压成形面临的重要课题。传统的优化方法需要大量的模拟计算,耗时多且不易掌握。针对这一问题,该文提出了将均匀设计法、神经网络和遗传算法相结合进行参数优化,既利用了均匀设计试验的均匀可靠性,又运用神经网络的非线性映射、网络推理和预测功能,最后发挥遗传算法的全局优化特性,得出了最优结果,并直接为实际生产提供了可靠的参数依据。     

铁含量及退火对高纯铝箔再结晶织构的影响

采用晶体取向分布函数 (ODF)、TEM研究了铁含量及退火对高纯铝箔再结晶织构的影响。结果表明 ,铁含量越高 ,立方织构越少 ,R织构越多。铁含量较少时 ,在成品退火的低温阶段 ,形成回复亚晶组织 ;高温退火时 ,在晶内析出含铁化合物 ,形成强烈的再结晶立方织构 ,R织构取向密度很小 ;铁含量较多时 ,无论采用何种退火工艺 ,再结晶织构中立方取向都较弱 ,而R取向都较强