Thixoforming of SiC ceramic matrix composites in pseudo-semi-solid state

1INTRODUCTIONIt has great economic profit to exploit the uti-lization of SiC ceramic material for its strength,hardness,wear resistance,corrosion resistanceand high temperature resistance,abundant re-source and low price.But the brittle charactergreatly restricts its application in the field of engi-neering structure materials.Recently a series ofceramic matrix composites with exi mious perform-ance have been developed by reinforcing the matrixmaterial with other materials.Al/SiC is a la…     

带材的纠偏控制

本文对带钢生产线上常见的带材跑偏现象，进行了详细的分析。对带钢跑偏的原因，进行了研究。同时，对带钢跑偏应采取的措施，也给出了相应的方法。     

Influence of alloy ingredients on mechanical properties of ternary boride hard alloy clad materials

Using Mo, B-Fe alloy and Fe powders as raw materials, and adding C, Cr and Ni ingredients, respectively, or C, Cr and Ni mixed powders, ternary boride hard alloy clad materials was prepared on Q235 steel substrate by means of in-situ reaction and vacuum liquid phase sintering technology. The influence of alloy ingredients on the mechanical properties of ternary boride hard alloy clad materials was investigated. The results indicate that a mixture of 0.8% C, 5% Cr and 2% Ni ingredients gives a ternary boride hard alloy clad material with optimal mechanical properties, such as high transverse rupture strength, high hardness and good wear resistance.     

Effects of catalyst precursors on carbon nanowires by using ethanol catalytic combustion technique

Iron nitrate, nickel nitrate and cobalt nitrate were used as catalyst precursors to study their effects on carbon nanowires synthesized by ethanol catalytic combustion （ECC） process. The as-grown carbon nanowires were characterized by means of scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that relatively uniform nanowires will be formed when the catalyst precursor is iron nitrate; while helical structure or disordered structure will be formed when the catalyst precursor is nickel nitrate or cobalt nitrate. precursor     

空间高能质子对飞行器材料的损伤分析

针对高能粒子在空间环境中的辐射,本文简要介绍了空间高能质子在空间环境中的分布情况及在物质中的传输问题,评述了国外有关高能质子的非电离能损失及线性能量转移研究,并在此基础上重点分析和研究了高能质子对航空、航天材料的辐射损伤.从空间高能质子对材料的辐射损伤的角度,分析讨论了材料厚度与屏蔽效果的关系并提出了一些相关性的结论和展望;能量为10MeV～80MeV的质子最可能发生辐射损伤效应,质子拟合公式适合于入射质子能量较小的情况.     

一种新型模具材料DGJ W40钢结硬质合金

采用一种特殊铸造工艺成功地研制了一种新型模具材料———DGJW40钢结硬质合金 ,它不仅可以锻造改形 ,还具有良好的热处理性能 ,用在拉丝、拉伸及挤压等模具上取得了良好的效果     

渗碳材料涡流测试系统的研究

以通用有限元分析软件ANSYS作为二次开发平台，开发了面向渗碳材料的涡流测试系统。该系统将有限元前处理、涡流电磁场计算、渗碳层深度逆问题求解及计算结果的可视化处理结合起来，提供了良好的用户界面。     

钢铁酸洗时氢致裂开危险性检测新技术的研究

研究了一种新型的原子氢渗透速率测量传感器在酸洗液中的测量信号与A3钢在相应体系中的强度/脆性之间的对应关系,为发展钢铁酸洗除锈除垢时在线检测氢致腐蚀裂开危险性的智能化新技术,提供了软件设计的部分关键参数与判据。     

一种新的位错运动理论及对材料动态力学行为的描述

通过对位错在晶格内运动的动力学过程的全面分析。本文提出了一种考虑到粘性阻尼效应和热激活的位错集体运动统一理论。其特点是可用一简单的方程对从低速到高速运动的大量位错的平均行为进行统一描述。对ＫＣｌ晶体的典型实验怕拟合发现理论描述与实验结果相当一致。     

A3钢焊缝区在酸性介质中氢致腐蚀裂开行为的研究

本文应用慢应变速率拉伸试验法、金相和扫描电镜技术研究了带焊缝的A3钢试样在会缓蚀剂的盐酸溶液中的氢致腐蚀裂开行为。结果表明,在酸液中带焊缝试样的断裂均发生在热影响区;带焊缝A3钢试样的脆断敏感程度显著高于其母材;缓蚀剂的添加可以较大程度地改变带焊缝材料的脆断敏感性。