航空结构材料研究进展

本文对航空系统结构材料的现状和进展，以及先进的材料和工艺对飞机和飞机发动机的进步所起的重要作用进行了全面系统的研究。本文的主要内容是关于航空和航空发动机材料，以及新材料在制造轻型结构中的作用。     

贵金属高温合金的研究现状及展望

简述了目前高温合金材料存在的问题,介绍了贵金属高温合金的主要特点,指出了研究贵金属高温合金的必要性,系统地综述了贵金属高温合金的研究成果、应用及目前存在的主要问题,最后展望了贵金属高温合金的研究方向。     

Mechanical behaviour of aluminium-lithium alloys

Aluminium-lithium alloys hold promise of providing a breakthrough response to the crying need for lightweight alloys for use as structurals in aerospace applications. Considerable worldwide research has gone into developing a range of these alloys over the last three decades. As a result, substantial understanding has been developed of the microstructure-based micromechanisms of strengthening, of fatigue and fracture as well as of anisotropy in mechanical properties. However, these alloys have not yet greatly displaced the conventionally used denser Al alloys on account of their poorer ductility, fracture toughness and low cycle fatigue resistance. This review aims to summarise the work pertaining to study of structure and mechanical properties with a view to indicate the directions that have been and can be pursued to overcome property limitations.     

Formation of non–equilibrium alloys by high pressure melt quenching

Melt quenching under high pressure can promote the formation of metastable materials. High pressure accelerates the amorphization of Cu₆₀Ti₄₀ and Cd₄₃Sb₅₇.For an alloy systems having volume expansion after solidification, the higher the applied pressure, the lower the melting point and the higher the amorphization temperature, which promotes the formationof metallic glass. High pressure also enhances nucleation and suppresses grain growth, so solidification under high pressure can refine the crystal grains to form nanocrystalline alloys, such as Ti₆₀Cu₄₀,Cu₇₀Si₃₀ and Pd₇₈Si₁₆Cu₆ alloys.     

Simulation of constrained dendrite growth of multicomponent alloys using a Calphad method

Abstract

The conventional theory of constrained dendrite growth for binary alloys has been extended to multicomponent alloys based on the Calphad method by consideration of solute interactions in each phase. The variable solute partition coefficients and liquidus slopes under different tip undercooling were calculated in detail for a series of Al-Si-Mg alloys. Their influence on the kinetics of dendrite growth was demonstrated quantitatively. The most important microstructure scale, the primary dendrite spacing, was predicted in several Al-Si-Mg alloys. By comparing with the experimental results of former researchers, it is found that the present method coupled with Calphad is a satisfactory way for the prediction of primary dendrite arm spacing.     

Fragility of superheated melts in Al–RE (Ce, Nd, Pr) alloy system

The fragility of superheated melt M, characterized by the temperature dependence of the viscosity scaled by the viscosity at the liquidus temperature, has been proposed by Bian et al. recently. In this work, the values of M of Al–RE(Ce, Nd, Pr) melts were calculated based on the viscosities measured in the range of less than 250 K above their liquidus temperatures. It was found that M has a good negative correlation with the glass-forming ability (GFA) in Al–RE binary alloy system. Although the previous study found that M could reflect the GFA in Al–Co–Ce alloy system, there is no good relationship between M and GFA in the alloy system including Al–RE and Al–Co–Ce alloys simultaneously. The relationship between fragility of superheated melts and glass-forming behavior in different Al-based alloy systems was elaborated.     

The Intelligent Design of Age Hardenable Wrought Aluminum Alloys

This paper describes a new approach for the design of improved age‐hardenable wrought aluminum alloys. We use as an example our current research program directed towards developing an Al‐Cu‐Mg‐X aluminum alloy for moderate temperature applications. The process involves extensive empirical research, theoretical simulation and modeling, first principle atomistic calculations, calculated phase diagrams and quantitative analytical techniques. We believe that the approach will lead to streamlined alloy design and therefore aid in the early insertion of new high performance materials. We will not cover alloy development being conducted elsewhere.     

Co-x%Mn合金中的fcc→hcp相变和相关的形状记忆效应

Co-Mn合金是磁诱发形状记忆效应候选材料之一，本文制备了不同Mn含量的Co-Mn合金，研究了合金成分对Co-Mn二元合金中应力诱发γ(fcc)→ε(hcp)马氏体相变及形状记忆效应的影响作用，研究结果发现，对于能够发生γ→ε马氏体相变的Co-Mn合金，具有部分形状记忆效应；随着Mn含量的增加，马氏体量减小，基体的强度降低，导致合金的形状回复率和可回复应变均有不同程度的下降。     

喷射成形技术制备高性能铝合金材料

采用喷射成形技术制备了过共晶Ａｌ－Ｓｉ系高强耐磨铝合金和Ａｌ－Ｚｎ系（７０００系）超高强铝合金,并对上述喷射成形材料的组织、性能进行了研究。结果表明,喷射成形材料与传统铸造材料或铸造变形加工材料相比,基本组织被显著细化、析出相尺寸更为细小且分布更加均匀、各种析出相的宏观和微观偏析得到了有效控制,从而使其各项力学性能得到了明显的提高。还同时介绍了上述喷射成形高性能铝合金在工业发达国家中的大规模应用情况,以及我国的应用开发现状。     

钛合金的应用和低成本制造技术

钛及钛合金具有优异的综合性能，是一种重要的金属结构材料，在军工、民用各个领域得到广泛的应用。简要阐述了钛合金的应用现状，分析了降低钛合金成本的可能性途径。