奥氏体不锈钢表面等离子渗锆合金层的抗酸腐蚀性研究

为提高0Cr18Ni9Ti奥氏体不锈钢在特殊应用环境的耐酸腐蚀性能,采用双辉等离子渗金属技术在不锈钢基体表面渗锆,对渗锆合金层的相结构进行检测分析,将奥氏体不锈钢基体试样和表面渗锆试样分别在0.5 mol/LH2SO4溶液、0.5mol/L HNO3溶液、0.5 mol/L HCl溶液进行电化学腐蚀对比试验。结果表明:在H2SO4溶液、HNO3溶液、HCl溶液中,不锈钢基材的相对腐蚀速度分别是渗锆合金层的2.18倍、9.73倍、24.43倍;不锈钢基体表面腐蚀较为严重,而渗锆合金层表面仅出现轻微的局部腐蚀坑。奥氏体不锈钢表面渗锆后,渗锆合金层中合金元素呈梯度分布,且腐蚀时在表面形成了一层致密的氧化锆钝化膜,因而其抗酸腐蚀性能相对基体大幅提升,在HCl溶液比在H2SO4溶液和HNO3溶液中耐蚀效果更明显。     

TM-Gd合金系非晶形成能力的热力学研究（I）

在Co-Gd二元系合金体系的热力学优化评估的基础之上,应用CALPHAD （ CALculation of PHAse Diagram）技术,研究此二元非晶合金的玻璃形成能力。本文分析了700 K、800 K时Co-Gd合金中各元素含量对非晶形成能力的影响,预测了非晶形成的最优成分,计算过冷液相中的结晶相形成驱动力。通过与部分实验和非晶共晶点准则的比较可见,本文所做的热力学分析对此二元合金的非晶制备具有一定的理论指导意义。     

Effect of boron addition on the microstructure and stress-rupture properties of directionally solidified superalloys

This study is focused on the effect of boron addition, in the range of 0.0007wt% to 0.03wt%, on the microstructure and stress-rupture properties of a directionally solidified superalloy. With increasing boron content in the as-cast alloys, there is an increase in the fraction of the γ′/γ eutectic and block borides precipitate around the γ′/γ eutectic. At a high boron content of 0.03wt%, there is precipitation of lamellar borides. Upon heat treatment, fine block borides tend to precipitate at grain boundaries with increasing boron content. Overall, the rupture life of the directionally solidified superalloy is significantly improved with the addition of nominal content of boron. However, the rupture life decreases when the boron content exceeds 0.03wt%.     

Mechanical,electrical, and thermal expansion properties of carbon nanotube-based silver and silver-palladium alloy composites

The mechanical, electrical, and thermal expansion properties of carbon nanotube（CNT）-based silver and silver–palladium（10：1, w/w） alloy nanocomposites are reported. To tailor the properties of silver, CNTs were incorporated into a silver matrix by a modified molecular level-mixing process. CNTs interact weakly with silver because of their non-reactive nature and lack of mutual solubility. Therefore, palladium was utilized as an alloying element to improve interfacial adhesion. Comparative microstructural characterizations and property evaluations of the nanocomposites were performed. The structural characterizations revealed that decorated type-CNTs were dispersed, embedded, and anchored into the silver matrix. The experimental results indicated that the modification of the silver and silver–palladium nanocomposite with CNT resulted in increases in the hardness and Young＇s modulus along with concomitant decreases in the electrical conductivity and the coefficient of thermal expansion（CTE）. The hardness and Young＇s modulus of the nanocomposites were increased by 30%？40% whereas the CTE was decreased to 50%-60% of the CTE of silver. The significantly improved CTE and the mechanical properties of the CNT-reinforced silver and silver–palladium nanocomposites are correlated with the intriguing properties of CNTs and with good interfacial adhesion between the CNTs and silver as a result of the fabrication process and the contact action of palladium as an alloying element.     

球磨参数及Ni比例对Mg2Ni合金储氢性能影响研究

采用中频感应炉熔炼出铸态Mg2 Ni合金,将Mg2Ni合金与一定量的Ni粉进行混合球磨处理.系统研究在不同Ni粉添加量及球磨时间等条件下所得合金样品的结构及储氢性能.研究表明,随着Ni含量的增大及球磨时间的延长,合金的非晶纳米晶结构逐渐增多;合金的最大放电容量及循环稳定性得到明显提升;合金的表面催化活性及合金体相内的H传输能力都有了显著提高.Ni粉的作用主要在于可促进合金非晶化,同时对合金的放氢过程起到了催化的作用.     

适用于电器附件的新型绝缘材料──PC/PET塑料合金

电器附件是确保民用电器和工业用电器设备供电的重要器件，对其应用材料有各种性能要求，尤其是作为支承导电零部件的绝缘材料，有较高的耐热，耐燃和耐漏电起痕等性能要求。本文介绍的PC/PET塑料合金能较好地满足要求，并且可以用于要求更高的非普通型电器附件作为支承载流零件的绝缘材料。     

高性能磁性材料与微粒子制备技术

使结晶粒子细化或微细化是提高现有材料性能、开发新型材料的有效手段之一．本文介绍各种微细和超微细磁性粒子的制备技术及其在开发高性能材料中的应用．     

多元素复合强化型高铬铸铁堆焊焊条的研制

采用Ｍｏ，Ｖ，Ｗ，Ｎｂ等合金元素对高铬铸铁堆焊焊条的焊层组织进行了改善，使其耐磨性明显提高，并对这些合金元素的作用进行了探讨     

Zr65Al7.5Ni10Cu15Co2.5合金的比热和热力学函数

采用差示扫描量热仪和差热分析测定了Ｚｒ６５Ａｌ７．５Ｎｉ１０Ｃ１５Ｃｏ２．５非晶合金的结晶温度和结晶焓，晶态和熔化温度和熔化焓，非晶态和晶态及液态的经热等热力学数据，在此基础通过设昌态２９８Ｋ的自由焓为零，得到了晶态，非晶态和液态的热力学函数，据此研究了玻璃转变和真实玻璃转为温度，分析了理想玻璃转为温度，真实玻璃转为温度和实际测量的玻璃转为温度的关系。     

Φ800钼合金冷硬球墨复合铸铁轧辊残余应力的测试分析

在确定Φ８００钼合金冷硬球墨复合铸铁轧辊残余应力的测试方案之后，对轧辊铸态，人工时效，自然时效后不同位置及距表面不同深度等测点进行了大量的测试工作，并对人工时效，自然时效对轧辊残余应力的影响结果进行了分析。