Development of Manufacturing Process of Multilayred Composite with Mesoscopic Microstucture

通过在介观尺度上控制微观结构来优化材料的性能是创造性地开发高性能新型材料的最重要的方法。为此，我们计划开发改进的曾傑瑞滚压技术，其特点是：(1)易于设计具有介观组织的复合材料；(2)通过重复塑性变形，有可能获得最终的高变形率的细丝。取得了以下成果。(A)首先设计了多层Nb-Ti/Nb复合结构，通过理论计算得到了在固定磁场下的最大临界电流密度。利用曾傑瑞滚压技术制备了理想的复合超导体。他们的表现令人满意。(2)制备了厚度为10 nm的Ag/Cu多层膜，其抗拉强度超过1300 Mpa，其值与理论克勒固体的估计值相同。(3)通过控制亚稳析出相的组织，研制出超高强铝合金，强度可达900 Mpa以上。

To optimize the property by controlling microstructure in mesoscopic scale is the most important methodology to develope creatively a new matrial with high performance. As one of those ideas, we have planned to develope the modified Jerry Roll technique, of which characteristic features are as follows ; (1) it is easy to design the composite with mesoscopic microstructure, (2) by repeating the plastic deformation, it is possible to get the final fine wire with very high deformation ratio. The following results have been obtained. (a) Firstly the multilayred Nb-Ti/Nb composite structure was designed owing to the theoretical calculation getting a maximum critical current density at a fixed magnetic feild. The ideal composite superconductors were fabricated by the Jerry Roll technique. Their performance was found to be satisfactory. (b) The multilayred Ag/Cu film with thickness of 10nm was fabricated, of which the tensile strength exceeds 1300 MPa, of which value is in the same order estimated from the theoretical Koehler solid. (c) The super-high strength aluminium alloys have been developed by controlling the structure of metadtable precipiates and realized the strength beyond 900 MPa.