高温钛合金Ti55/Ti60真空电子束焊接

对 Ti55 与 Ti60 合金薄板进行了电子束焊接,研究了电子束焊接工艺参数对接头组织及力学性能的影响.结果表明,焊缝区形成大量针片状的α' 马氏体,焊缝中心为粗大的柱状晶.焊接工艺参数对焊缝组织和接头抗拉强度有一定影响,接头室温抗拉强度高于母材,600℃时接头抗拉强度与 Ti60 母材相当,抗弯强度达到母材的 80% 左右,冲击韧度能够达到母材的 90% 以上,断裂发生在热影响区处,为韧性断裂.

Abstract：

Ti55 and Ti60 titanium alloy sheets were welded by electron beam, and the influences of parameters on microstmcture and mechanical properties of welding joints were studied. The results show that weld zone is characterized by acicular α' martensite plate,and weld center is formed by coarse columnar crystals. Welding parameters can affect microstructure and tensile strength to a certain extent. At room temperature, the tensile strength of joint is higher than that of base metal. At a higher temperature of 600 ℃, tensile strength of joint is about equal to that of Ti60, and bending strength can be up to 80% of that of base metal, even impact toughness also can be larger than 90% of base metal. Failure occurs in heat-affected zone, and the fracture mode shows toughness characteristic.     

铜基石墨烯复合催化剂的合成与表征

采用原位水热法制备了Cu/rGO催化剂并引入对苯二甲酸(TPA)对Cu基石墨烯复合材料进行改性研究，探究了不同溶剂、水热时间、沉淀pH对引入TPA的Cu/rGO催化剂材料微观结构特性的影响。通过XRD、FT-IR、XPS和SEM表征技术分析了催化剂的形貌结构及物化性质。考察了催化剂用于二乙醇胺脱氢的催化性能。在V_(乙醇)∶V_(水)=1∶1为溶剂，沉淀pH为13.0，160℃水热10 h，制备的催化剂性能最好，亚氨基二乙酸收率为86.55%，与没有添加TPA的Cu/rGO催化剂相比收率提高20%。TPA的加入，增强了GO片层间的相互作用，增加了GO片层间的有机官能团，稳定Cu₂O并使其结晶度较好，增加催化剂活性位点，以提高反应速率。且粒径约为10 nm左右的Cu纳米粒子均匀分布在褶皱状片层结构的rGO表面，提高催化剂抗烧结性能。