Platform Science and Technology for Advanced Magnesium Alloys -Extra Light Metals in the 21st Century-

先进镁合金平台科学与技术-21世纪的超轻金属-

基本信息

批准号：
11225101
负责人：
KOJIMA Yo
金额：
$ 45.76万
依托单位：
Nagaoka University of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11225101/
关键词：
Magnesium Alloys Microstructure and Structure Control Surface and Interface Control Recycle Optimum Design for Lightening Semi-Solid Forming Process New Functionality Surface Modification プロチウム吸蔵合金

项目摘要

In the current four-year term project, new platform science and technology is proposed as a core concept of research and development of advanced magnesium alloys together with understanding of their intrinsic characteristics. The research fields related to advanced super-light magnesium alloys for 21st Century have been focused to the selected three categories ; ( 1)Search for new premium alloys and a structural design from the view points of microstructure control, (2)Establishment of environmental-friendly surface modification and recycling for the ecomaterials desing and green processing, and (3)High performance design and processing in functionality. Each research group is introduced together with its strategic directions toward future R & D for advanced magnesium alloys and has its own joint research network to drive new research directions.Typical results are summarized as follows ; a nanocrystalline Mg-1mol%Zn-2mol%Y bulk alloy sample prepared by warm extrusion of rapidly solidi … More fied powders is composed of grains of about 50-200 nm in diameter, which are divided into two types; hcp-Mg solid solution grain and fine-lamellar grains consisting of a novel long-period ordered structure with hexagonal lattice of 6H-type (ABCBCB)., resulting in high 0.2% proof strength of about 610 MPa and sufficient elongation of about 5% at room temperature. Dislocation cross slip from basal plane to non-basal planes, dynamic recovery within twins and in untwined matrix, and grain boundary sliding are found to occur in whole grains of the magnesium alloy specimens with fine-grains of lower than 10μm even at room temperature. AZ61 alloy specimen indicates high strength of 350MPa and high ductility of 33% by the refinement of grains and precipitates caused by dynamic recrystallization and dynamic precipitation during severe warm working. To be free from the classical theory, materials design on the basis of the first principle molecular dynamics calculation is proposed for new high creep resistant magnesium alloys. A protective high purity coating applying magnesium vapor deposition technique, polymer plating of triazine dithiols easily peeled at the cryogenic temperature or decomposed by brittle fracture, and their solid state recycling technology are developed as environmentally benign surface modification without chromium. The co-electrodeposition of rare earth metals (RE) with Mg in the molten salt system including RE chlorides is found to be available for the production of Mg-RE alloys. Also, semi-solid continuous casting process is established for the fabrication of fine-and globular-grained billet and adequate magnesium alloys is developed for high speed semi-solid processing at lower temperatures as a near net complex shape forming process. As a new route to fabricate the functional magnesium alloys, bulk mechanical alloying process as a solid state synthesis was proposed to successfully synthesize the magnesium base hydrogen absorbing alloys and thermoelectric semiconductor in the solid state with fine structure and accurate chemical composition. This bulk mechanical alloying also provides us non-equilibration to make solid state synthesis. Furthermore, ternary or quaternary magnesium base alloy bulk can be directly fabricated to have the same chemical composition as predicted in design at extremely lower temperature than the melting temperatures of constitutive elements. On this fundamental knowledge, the solid-state recycling is proposed to fabricate the reinforced magnesium alloy composite parts and performs with in-situ precipitated Mg_2Si and MgO in fine and uniform.On the basis of the obtained results, platform science and technology for environmentally benign and high performance magnesium alloys is constructed as an industrial base material for the next generation. Less

在当前的四年期项目中，提出了新平台科学技术作为先进镁合金研发的核心概念，并了解其内在特性，与21世纪先进超轻镁合金相关的研究领域。重点关注选定的三个类别；（1）从微观结构控制的角度寻找新型优质合金和结构设计，（2）建立环境友好型表面改性和回收的生态材料设计和绿色加工，以及(3)高每个研究小组都介绍了先进镁合金未来研发的战略方向，并拥有自己的联合研究网络来推动新的研究方向。典型成果总结如下：快速凝固粉末温挤压制备的1mol%Zn-2mol%Y块体合金样品由直径约50-200 nm的晶粒组成，分为两种类型； hcp-Mg固溶体晶粒和细片状晶粒由具有6H型六方晶格（ABCCBCB）的新型长周期有序结构组成，从而产生约610 MPa的高0.2%屈服强度和约5%的足够伸长率在室温下，发现整体上发生位错从基面到非基面的交叉滑移、孪晶内和未缠绕基体中的动态恢复以及晶界滑动。即使在室温下，AZ61合金试件的晶粒也具有小于10μm的细晶粒，通过剧烈温热过程中动态再结晶和动态析出引起的晶粒和析出物的细化，表现出350MPa的高强度和33％的高延展性。为了摆脱经典理论的束缚，提出了基于第一原理分子动力学计算的材料设计，用于新型高抗蠕变镁合金的应用。镁气相沉积技术、三嗪二硫醇聚合物镀层在低温下容易剥离或脆性断裂分解，其固态回收技术被开发为无铬的环境友好型表面改性稀土金属（RE）与稀土金属（RE）的共电沉积。发现包含稀土氯化物的熔盐体系中的镁可用于生产镁稀土合金，并且还建立了用于制造镁稀土合金的半固态连续铸造工艺。细粒和球状晶粒坯料和足够的镁合金是为在较低温度下进行高速半固态加工而开发的，作为一种近净复杂形状成形工艺，作为制造功能性镁合金的新途径，块体机械合金化工艺作为一种固体。提出了固态合成方法，成功地合成了具有精细结构和精确化学成分的固态镁基吸氢合金和热电半导体，这种块体机械合金化还为我们提供了非平衡态合成。此外，三元或三元材料也可以在固态下合成。四元镁基合金块体可以在比构成元素熔化温度极低的温度下直接制造成具有与设计预测相同的化学成分，基于这一基本知识，提出了固态回收来制造增强镁合金复合材料。在此基础上，构建了环境友好型高性能镁合金科学技术平台，作为镁合金材料的工业基础材料。下一代少。