16Co14Ni10Cr2Mo钢力学性能与应力腐蚀行为

研究了１６Ｃｏ１４Ｎｉ１０Ｃｒ２Ｍｏ钢不同温度回火５ｈ强度、冲击韧性、断裂韧性和应力腐蚀性能（在３．５％ＮａＣｌ水溶液中）。在５１０℃回火可以获得较高的强度，最高的断裂韧性及抗应力腐蚀性能，此时Ｋ＿（ＩＳＣＣ）可达，Ｋ＿（ＩＣ）为，屈服强度为１５８０ＭＰａ。应力腐蚀性能（ＳＣＣ）的改善主要与在较高温度回火，使Ｍｏ＿２Ｃ共格造成的应力下降，位错亚结构的恢复及碳化物的粗化，并导致氢的偏聚下降有关。     

30CrMnSiNi2A钢强韧化热处理的研究

 用正交试验法研究了等温温度、等温时间、奥氏体化温度和原始组织状态对30CrMnSiNi2A钢组织和性能的影响,提出了可保证该钢在上、中、下限碳量时各项性能均达到技术要求的热处理工艺。对新工艺显著改善钢强韧性的原因作了分析,研究了30CrMnSiNi2A钢在250～280℃温度范围等温淬火后K_(IC)值出现低谷的现象,并认为在该热处理条件下在马氏体与贝氏体交接面处有大量孪晶马氏体存在以及组织中有许多平行排列的细长等温马氏体板条束出现,是造成K_(IC)值降低的主要原因。     

一种三维并行自适应计算方法

基于串行网格划分软件METIS与并行化消息传递编程接口（ MPICH2）对现有串行自适应程序进行简单的并行化改造,给出了一种三维可压缩无粘流数值模拟的并行自适应方法。首先利用单个进程调用METIS,串行划分网格;然后对所有进程并行计算以获得初始网格下的流场解;再次利用单个进程对整个流场运用自适应方法进行局部网格加密并调用METIS串行划分网格;最后全部进程在流场初始解的基础上继续并行计算,以获得自适应网格下的流场解。数值模拟算例验证了此方法的可靠性与高效性。     

Cf / E-TiO2 复合材料的制备与性能

采用复合分散工艺将纳米TiO_2均匀分散于环氧树脂中,制备了环氧-纳米TiO_2树脂浇铸体,并采用湿法缠绕工艺制备了T700碳纤维增强环氧复合材料(C_f/E)以及T700碳纤维增强环氧-纳米TiO_2(C_f/ETiO_2)复合材料NOL环与Φ150 mm容器,研究了纳米TiO_2对环氧树脂浇铸体、复合材料NOL环和Φ150 mm容器性能的影响。结果表明,纳米TiO_2的加入对环氧基体和C_f/E复合材料均有不同程度的增强、增韧效果,其中环氧基体的拉伸强度提高了9.2%,弯曲强度提高了9.8%,冲击强度提高了52.9%;C_f/E-TiO_2复合材料NOL环层剪强度达到87.7 MPa,提高了22.3%;Φ150 mm容器特性系数达到43.4 km,纤维强度发挥率达到94.3%,分别提高了9.9%和3.3%。     

人体代谢耗氧模拟方法研究

利用沸石分子筛对氧气和氮气选择性吸附的特性,提出了分子筛吸附-解吸模拟密封舱内人体消耗氧气的方法,研制了能够模拟5人耗氧量的试验装置,并对装置的富氧气体氧浓度、密封舱内气体成分吸附情况、耗氧模拟精度及补氮气功能等进行了测试和分析,经环控生保系统集成性能试验的使用考核,装置出口富氧气体氧浓度可达93%以上,耗氧模拟精度优于5%,基本不消耗密封舱内的其它气体成分,能够较好地模拟人体对氧气的消耗。结果表明:分子筛耗氧模拟方法精度高,对密封舱内气体成分影响小,装置工作稳定性好,适用于长期载人航天任务中密封舱环境参数控制能力的研究。     

热处理对9 Cr13 Mo3 Co3 Nb2 V组织与硬度的影响

采用金相分析、硬度测试等技术手段,研究热处理对马氏体不锈钢9Cr13Mo3Co3Nb2V组织和硬度的影响。结果表明：9Cr13Mo3Co3Nb2V经淬火、冰冷处理及多次回火后,残余奥氏体充分转变为回火马氏体,并产生较强的二次硬化效果,进而获得稳定的组织和高的硬度;在350℃以上回火时,由于组织中二次碳化物的析出,开始出现二次硬化倾向,至480~520℃时,回火硬度达到了最大值。     

Ti2AlNb合金双层辉光等离子表面渗钼的扩散行为研究

Ti2AlNb合金(O相)具有高的比强度、断裂韧性以及优良的抗蠕变性能,因而在航空制造中成为一种颇具吸引力的高温结构材料.但是,较差的耐磨性是其主要的缺陷并限制其实际应用.为解决这一问题,对Ti2AlNb合金进行双层辉光等离子表面渗Mo.探讨主要工艺参数对Mo的扩散行为的影响.采用扫描电镜(SEM)、X射线衍射(XRD)和辉光放电光谱仪(GDS)分析表面合金化层的成分分布和微观结构.测定从表面到中心的显微硬度变化曲线.结果表明温度与时间均对扩散过程具有显著的影响.最后通过回归分析计算出在优化的工艺温度980℃下的扩散系数.     

Preparation and Microstructure of Cu/Ti_3SiC_2 Nanocomposite

Mixed micron-sized Cu/Ti3SiC2 (vol5%) powder was mechanically milled using agate balls and zirconia balls separately. Then followed an examination of it with the FEI-SEM. The experimental results show that, distributed homogenously in Cu matrix, the Ti3SiC2 particles have a size of about 30-50 nm after milled with agate balls for 8 h, while it remains approximately unchanged after milled with zirconia balls. The microstructure of the mixture at different ball-milling stages was also studied. Bulks of Cu/Ti3SiC2 nano-composite were fabricated by hot pressing nano-sized Cu/Ti3SiC2 powder at the temperature of 1 073 K under 100 MPa. Then came an investigation of the effects of the particle size and agglomerate state of Ti3SiC2 as well as the microstructure of Cu/Ti3SiC2 nano-composite. It was found that the nano-sized Ti3SiC2 particles distribute evenly in copper.     

Electrolytic Passivation of Nitinol Shape Memory Alloy in Different Electrolytes

The corrosion behavior of the nitinol alloy was studied in various corrosion media of different Cl^- ion concentrations. The results demonstrate that the Cl^- ion concentration has significant influences on the corrosion behavior of the nitinol alloy. In order to enhance the corrosion resistance, protective films were generated on the surface of the nitinol alloy by means of the electrochemical passivation method, for which five different electrolytic solutions were investigated. The surface analysis indicates full growth of all samples passivated in the different electrolytic solutions with layers, however, showing different morphological features. Without any defects like micro-cracks and pores, the surface of the samples passivated in the molybdate solution turns out smoother and denser than those passivated in other solutions. It is shown that the electro-chemical passivation will reduce Ni content but increase Ti content in the surface, reaching the Mole ratio of Ti：Ni = 9.01：1 on the outermost surface. Potentiodynamic polarization test demonstrates that the samples electrochemically passivated in the molybdate solution present a significant increase in breakdown potential due to titanium enrichment on the outermost surface.     

不同制备工艺对MoSi2涂层抗氧化性能的影响

为解决MoSi2和SiC线膨胀系数差异,在带有SiC外涂层的C/C复合材料表面采用等离子喷涂、电弧沉积和固渗等工艺制备MoSi2涂层。涂层表面形貌分析发现,等离子喷涂MoSi2涂层多孔不致密,电弧沉积MoSi2涂层易开裂剥落;而固渗MoSi2涂层致密均匀,且界面结合力好。氧化试验也表明,固渗MoSi2涂层性能较好。