纳米SiC颗粒增强铝基复合材料制备工艺进展

介绍了纳米SiC颗粒增强铝基复合材料的发展现状,重点介绍和评述了国内外几种制备工艺的研究现状和应用,分析了纳米SiC颗粒增强铝基复合材料的微观结构,指出了纳米SiC颗粒增强铝基复合材料研究中存在的几个重要问题,展望了其未来的发展趋势.     

高性能铝基复合材料研究进展

自1960年代以来,全球持续开展了铝基复合材料研究,研发了损伤容限型、耐蚀型、高强型、耐热型、低膨胀型等一系列高性能铝基复合材料。这些复合材料已应用于航空、航天、电子和交通领域。然而,与传统金属材料和树脂基复合材料相比,目前高性能铝基复合材料的应用市场仍然很小。本文综述了高性能铝基复合材料在增强体、铝基体、制备方法、组织、性能和应用等方面的进展,讨论了在原材料、工程化、质量稳定性、性能数据、成本、应用和材料研制等方面存在的问题,从应用基体研究、材料研制、工程化、应用等方面展望了未来发展方向。高性能铝基复合材料的未来发展方向包括提升原材料质量、改善工艺稳定性、降低成本、加强工程化、扩大应用、探索增材制造+模锻技术及研制新一代纳米增强和纳米/微米混杂增强铝基复合材料。     

纳米SiC颗粒增强铝基复合材料制备工艺研究

本文介绍纳米复合材料的发展现状,重点介绍几种固态法制备纳米SiC颗粒增强铝基复合材料的工艺.分析铝基复合材料的显微组织,综合评价纳米SiC颗粒增强铝基复合材料制备工艺中存在的几个重要问题,并提出解决方案.在展望其应用前景基础上,指出制备技术未来的发展方向.     

高性能铝基复合材料研究进展EI北大核心

自1960年代以来,全球持续开展了铝基复合材料研究,研发了损伤容限型、耐蚀型、高强型、耐热型、低膨胀型等一系列高性能铝基复合材料。这些复合材料已应用于航空、航天、电子和交通领域。然而,与传统金属材料和树脂基复合材料相比,目前高性能铝基复合材料的应用市场仍然很小。本文综述了高性能铝基复合材料在增强体、铝基体、制备方法、组织、性能和应用等方面的进展,讨论了在原材料、工程化、质量稳定性、性能数据、成本、应用和材料研制等方面存在的问题,从应用基体研究、材料研制、工程化、应用等方面展望了未来发展方向。高性能铝基复合材料的未来发展方向包括提升原材料质量、改善工艺稳定性、降低成本、加强工程化、扩大应用、探索增材制造+模锻技术及研制新一代纳米增强和纳米/微米混杂增强铝基复合材料。     

铝基非晶态合金的研究进展

铝基非晶态合金及其非晶复合材料具有高强、高韧、轻质、廉价、耐蚀等特点,具有广阔的应用前景.就该领域玻璃形成能力、热稳定性及纳米晶化等热点问题进行了较详尽的综述.Trg准则不适用于判断铝基合金的玻璃形成能力,无玻璃转变的合金亦可具有强的玻璃形成能力.纳米晶化产物的小尺寸是由析出物周围溶质富集、阻碍长大造成的;高密度成因仍存在分歧.     

颗粒增强铝基复合材料的特种加工研究进展

铝基复合材料具有优良的物理力学性能,在航空,航天及军事等领域得到广泛应用。但材料的难加工特性限制了传统加工方法的应用。因此,对铝基复合材料必须进行特种加工,本文从铝基复合材料的特种加工方法、加工质量等方面综述了国内外铝基复合材料加工技术的进展情况,并指出了当前存在的问题及解决对策。     

镁铝纳米层状复合材料的简介

简单叙述镁基复合材料的研究现状,综述了层状金属复合材料的多种制备方法及其优缺点,并重点介绍复合轧制法来制备镁铝纳米层状复合材料。主要阐述镁铝复合相的表面自纳米化处理技术,特别是机械研磨技术的应用。展望了镁铝纳米层状复合材料的发展前景。     

纳米碳/铝复合材料强韧化研究现状及展望

以碳纳米管、石墨烯为代表的超高性能纳米碳,具有优越的力、热、电等综合性能,是复合材料的理想增强体,以纳米碳为强化相少量加入到铝中,有望开发出高强、高模、低热膨胀的复合材料,并使复合材料保持轻质、易加工等特性,在航空、航天、国防等领域具有重大的应用前景,因而以纳米碳/铝为代表的新一代铝基复合材料备受关注。然而,碳纳米管等纳米碳易团聚,与铝等大多数金属并不浸润,且容易分布在晶界上诱导显著的晶粒细化,使得复合材料的强韧性等关键性能指标提升困难,或者使强度提高的同时使塑韧性下降显著,限制了其工程应用潜力。综述近年来国内外研究者在纳米碳/铝复合材料强韧化方面的策略和方法,包括纳米碳分散、界面和构型调控等,以期推动新一代轻质高强纳米碳/铝复合材料的发展,支撑国家未来重大工程应用。     

颗粒增强铝基复合材料在航空航天领域的应用

详细介绍了制备颗粒增强铝基复合材料较为成熟的4种工艺,分析了各自的优缺点,综述了颗粒增强铝基复合材料在国内外航空航天领域中的一些成功应用,同时对我国发展颗粒增强铝基复合材料提出了一些建议.     

等通道挤压制备铝基细晶材料的研究进展

近年来,铝基材料因高的比强度和断裂韧性在工业领域获得广泛应用。剧烈塑性变形(SPD)加工是目前最有效的金属细晶化工艺,其中等通道挤压工艺(ECAP)因可稳定制备出具有良好综合性能的超细晶或纳米晶铝基材料而备受关注。本文综述了利用ECAP技术制备铝基细晶材料的相关研究进展,利用有限元模拟和实验综合探讨了挤压温度、摩擦系数、挤压速度、挤压路径、背压等工艺参数对铝基材料ECAP过程的影响,并通过分析国内外最新铝基材料ECAP工艺成果展望该工艺可能的发展方向。     

Tensile behavior of bulk nanostructured and ultrafine grained aluminum alloys

In the present study, data on tensile behavior of bulk nanostructured aluminum alloys processed via consolidation of mechanically milled powders and severe plastic deformation are analyzed. High strength and low strain hardening were observed in bulk nanostructured and ultrafine-grained Al alloys. The ductility of aluminum alloys decreases with decreasing grain size. The high amount of intercrystalline components may have an influence on tensile properties of bulk nanostructured materials when grain sizes are less than 100 nm. The high strength in bulk nanostructured Al-Mg alloy may be attributed to contributions arising from grain size strengthening, the presence of high dislocation densities, Orowan strengthening, precipitation hardening and solid-solution hardening. The large and sudden stress drops in the stress-strain curves of cryomilled Al alloys are most probably indicative of the dislocation annihilation in the vicinity of or breakaway from the strong pinning role of dispersoids.     

The new trends in fabrication of bulk nanostructured materials by SPD processing

During the past decade, fabrication of bulk nanostructured metals and alloys using severe plastic deformation (SPD) has been evolving as a rapidly advancing direction of nanomaterials science and technology aimed at developing materials with new mechanical and functional properties for advanced applications. The principle of these developments is based on grain refinement down to the nanoscale level via various SPD techniques. This paper is focused on investigation and development of new SPD processing routes enabling fabrication of fully dense bulk nanostructured metals and alloys with a grain size of 40–50 nm and smaller, namely, SPD-consolidation of powders, including nanostructured ones, as well as SPD-induced nanocrystallization of amorphous alloys. We also consider microstructural features of SPD-processed materials that are responsible for enhancement of their properties.     

Elaboration of aluminum-matrix composite materials reinforced with inorganic fibers

This article is a literature survey concerning the different methods presently known for producing fiber-reinforced aluminum-matrix composites. The elaboration problems are discussed in terms of wettability between aluminum or aluminum alloys and inorganic fibers. The fibers involved are continuous monofilaments about 100 μm diameter such as boron or silicon carbide fibers, and tows of 500–6000 endless thinner filaments 5–15 μm as graphite fibers, alumina fibers and Nicalon silicon carbide fibers. The typical mechanical properties (strength, modulus, fatigue) attained with these reinforcing fibers are also reported.     

航空铝合金的发展回顾与展望

铝合金是飞机机体的主要结构用材,其发展应用与飞机的发展息息相关.回顾了国内外航空铝合金的发展历史,对比分析了国内外航空铝合金的研制和应用差距.结合国外最新铝合金和飞机的发展,分析了铝合金的应用情况并提出了航空铝合金下一步的发展方向,指出铝合金仍将作为飞机的主结构材料而广泛使用.     

Dynamic Plastic Deformation （DPD）： A Novel Technique for Synthesizing Bulk Nanostructured Metals

While some superior properties of nanostructured materials （with structural scales below 100 nm） have attracted numerous interests of material scientists, technique development for synthesizing nanostructured metals and alloys in 3-dimensional （3D） bulk forms is still challenging despite of extensive investigations over decades. Here we report a novel synthesis technique for bulk nanostructured metals based on plastic deformation at high Zener-Hollomon parameters （high strain rates or low temperatures）, i.e., dynamic plastic deformation （DPD）. The basic concept behind this approach will be addressed together with a few examples to demonstrate the capability and characteristics of this method. Perspectives and future developments of this technique will be highlighted.     

Nanostructuring of metals by severe plastic deformation for advanced properties

Despite rosy prospects, the use of nanostructured metals and alloys as advanced structural and functional materials has remained controversial until recently. Only in recent years has a breakthrough been outlined in this area, associated both with development of new routes for the fabrication of bulk nanostructured materials and with investigation of the fundamental mechanisms that lead to the new properties of these materials. Although a deep understanding of these mechanisms is still a topic of basic research, pilot commercial products for medicine and microdevices are coming within reach of the market. This progress article discusses new concepts and principles of using severe plastic deformation (SPD) to fabricate bulk nanostructured metals with advanced properties. Special emphasis is laid on the relationship between microstructural features and properties, as well as the first applications of SPD-produced nanomaterials.     

Unique mechanical properties of nanostructured metals

Recently, it becomes possible to fabricate bulk metals having ultrafine grained or nanocrystalline structures of which grain size is in nano-meter dimensions. One of the promising ways to realize bulk nanostructured metals is severe plastic deformation (SPD) above logarithmic equivalent strain of 4. We have developed an original SPD process, named Accumulative Roll Bonding (ARB) using rolling deformation in principle, and have succeeded in fabricating bulk nanostructured sheets of various kinds of metals and alloys. The ARB process and the nanostructured metals fabricated by the ARB are introduced in this paper. The nanostructured metals sometimes perform quite unique mechanical properties, that is rather surprising compared with conventionally coarse grained materials. The unique properties seem to be attributed to the characteristic structures of the nano-metals full of grain boundaries.     

Fabrication and growth mechanism of one-dimensional Heusler alloy nanostructures with different morphologies on anodic aluminum oxide template by magnetron sputtering

Heusler alloys are a kind of intermetallic compounds with highly-ordered arrangement of atoms. Many attractive functional materials have been developed in Heusler alloys. Due to the application requirements of materials in new-generation electronic devices and spintronics devices, one-dimensional nanostructured Heusler alloys with special functions are needed. In this work, it is proposed to grow one-dimensional Heusler alloy nanostructures (1D-HA-NSs) by magnetron sputtering plus anodic aluminum oxide (AAO) template. Nanowires with different shapes, amorphous-coated (AC) nanowires and nanotubes were successfully grown for several Heusler alloys. AC nanowires are the unique products of our method. Heusler alloy nanotubes are reported for the first time. The one-dimensional nanostructures grow on the surface of the AAO substrate rather than in the holes. The top of the pore wall is the nanostructure growth point, the shape of which determines the morphology of the nanostructures. A general growth mechanism model of one-dimensional nanostructures on AAO template was established and further confirmed by experimental observation.     

Structure and properties of bulk nanostructured alloys synthesized by flux-melting

Nanomaterials can easily be prepared as thin films and powders, but are much harder to prepare in bulk form. Nanostructured materials are prepared mainly by consolidation, electrodeposition, and deformation. These processing techniques have problems such as porosity, contamination, high cost, and limitations in refining the grain size. Since most bulk engineering metals are initially prepared by casting, we developed a casting technique, flux-melting and melt-solidification, to prepare bulk nanostructured alloys. The casting technique has such advantages as simplicity, low cost, and full density. In our method, Ag–Cu alloys were melted in B₂O₃ flux, which removed most of the impurities, mainly oxides, in the melts. Upon solidifying the melt at a relatively slow cooling rate on the order of 10¹–10² K/s a large undercooling of ∼0.25 T _m (where T _m is the melting temperature) was achieved. This large undercooling leads to the formation of bulk nanostructured Ag–Cu alloys composed of alternative Ag/Cu lamella and nanocrystals, both ∼50 nm in dimension. Our liquid-processed alloys are fully dense and relatively free from contamination. The nanostructured Ag–Cu alloys have similar yield strength in tension and in compression. The as-quenched alloys have yield strength of 400 MPa, ultimate tensile strength (UTS) of 550 MPa, and plastic elongation of ∼8%. The UTS was further increased to ∼830 MPa after the as-quenched alloy rod was cold drawn to a strain of ∼2. The nanostructured Ag–Cu alloys show a high electrical conductivity (∼80% that of International Annealed Copper Standard), a slight strain hardening (strain-hardening coefficient of 0.10), and a high thermal stability up to a reduced temperature of 2/3 T _m. Some of these behaviors are different than those found in previous bulk nanostructured materials synthesized by solid state methods, and are explained based on the unique nanostructures achieved by our flux-melting and melt-solidification technique.     

Production, properties and application prospects of bulk nanostructured materials

Fundamental mechanisms of grain refinement during equal-channel angular pressing (ECAP) and multiple isothermal forging (MIF) are analyzed and compared. Based on this analysis, deformation methods of nanostructuring are classified into severe plastic deformation and mild plastic deformation methods. It is demonstrated that MIF is a versatile method allowing for a production of bulk and sheet nanostructured semi-products with grain size down to 50 nm and applicable to various metals and alloys. Novel mechanical properties of bulk nanostructured materials produced by this method are presented. The ways of their structural and functional applications are discussed.