Estimation system of weldability for materials joining based on knowledge data base of fusion processing technologies

本研究的目的是开发基于熔化加工技术知识库的结构材料接头焊接性评价系统，为具有新功能特性的结构材料焊接性知识库的支持数据做准备。评价系统由钢板种类、接头类型、焊接工艺、焊接材料、焊缝强度和防止焊接冷裂纹的氢含量等不同框架以及钢板种类、接头类型、焊接工艺和焊缝韧性估算的Charpy和CTOD值组成。将该系统录入大量的数据中，进行了焊接裂纹试验、夏比试验和CTOD试验。该系统可以控制合适的预热和后热温度，估算焊缝的韧性。对碳化硅/钛系纤维增强金属基复合材料、钛镍形状记忆合金和结构钢表面改性的连接性能进行了试验研究。采用真空热压法制备了碳化硅/钛复合材料，并分析了纤维与基体的反应对强度的影响。对钛镍形状记忆合金及其激光焊接接头的力学性能和断口进行了研究。采用10KW激光进行对接焊接。激光焊接试件表现出良好的形状记忆效应和超弹性。利用不同的金属粉末和硬质合金粉末，采用等离子转移弧法、等离子喷涂和激光熔覆等熔融处理技术，在某结构钢基材上制备了碳化物弥散复合材料和NiCrAlY复合材料。采用上述方法在结构钢基材表面涂覆一层复合合金层，使其表面具有新的功能特性。

The purpose of the study is to develop a estimation system of weldability for structural materials joining based on a knowledge data base of fusion processing technologies and to prepare the supporting data of the knowledge data base for weldability of structural materials having a new functional properties.The estimation system was constructed of the various frame such as kind of steel plates, type of joints, welding procedures, welding materials, strength of weld and contents of hydrogen for the prevention of weld cold cracking, and also, such as kind of steel plates, type of joints, welding procedures and Charpy and CTOD values for estimation of toughness of weld. The system were put into numerous data which the weld cracking test, Charpy and CTOD tests were curried out. The system can be controlled the suitable preheating and post-heating temperature, and estimated the toughness of weld.The works were curried out some experiments to investigated the joining properties for SiC/Ti system fiber reinforced metal matrix composite, Ti-Ni shape memory alloy and surface modification of structural steel. SiC/Ti FRM was produced by vacuum hot pressing and analyzed the effect of reaction of fiber-matrix on strength. Mechanical properties and fracture of Ti-Ni shape memory alloy and its laser weld joint have been investigated. Butt welding was performed using lOkW laser. The laser welded specimens showed a successful shape memory effect and super elasticity. These properties were identical with those of the base metal.The composite materials such as carbide dispersed composite materials and NiCrAlY composite material were produced on some structural steel substrate using various metal powders and carbide powders by fusion processing technologies such as plasma transfer arc method, plasma spraying and laser cladding process. As the structural steel using as substrate was overlaid the layer of composite alloy by above method, it's surface has new functional property.