Review on preparation techniques of particle reinforced metal matrix composites

The need for new engineering materials with theadvancement of modern technology in the areas ofaerospace, automotive and numerous other industries haslead to a rapid development of metal matrix composites(MMCs) [1]. They can be tailored to have outstandingmechanical and physical properties such as high specificstrength and stiffness, good wear resistance, enhancedhigh-temperature performance, and better thermal andmechanical fatigue and creep-resistance than that ofmonolithic materials. Among…     

改善颗粒增强金属基复合材料塑性和韧性的途径与机制

评述了影响颗粒增强金属基复合材料塑性和韧性的各种因素,在此基础上深入研究了颗粒形状对ＳｉＣｐ／ＬＤ２复合材料塑性和断裂韧性的影响规律。采用有限单元法分析不同形状的ＳｉＣ颗粒增强的ＬＤ２复合材料的微区力学环境和整体力学行为,结果表明颗粒的尖锐化导致基体内应变集中和颗粒尖端断裂的可能性加剧,因而降低材料的塑性;而在外加载荷的作用下,由于复合材料基体整体均处于较高的加工硬化状态,因此颗粒形状对材料断裂韧     

Effect of deformation temperature on the hot compressive behavior of metal matrix composites with misaligned whiskers

A multi-inclusion cell model is used to investigate the effect of deformation temperature and whisker rotation on the hot compressive behavior of metal matrix composites with misaligned whiskers. Numerical results show that deformation temperature influences the work-hardening behavior of the matrix and the rotation behavior of the whiskers. With increasing temperature, the work hardening rate of the matrix decreases, but the whisker rotation angle increases. Both whisker rotation and the increase of deformation temperature can induce reductions in the load supported by whisker and the load transferred from matrix to whisker. Additionally, it is found that during large strain deformation at higher temperatures, the enhancing of deformation temperature can reduce the effect of whisker rotation. Meanwhile, the stress-strain behavior of the composite is rather sensitive to deformation temperature. At a relatively lower temperature （150℃）, the composite exhibits work hardening due to the matrix work hardening, but at relatively higher temperatures （300℃ and above）, the composite shows strain softening due to whisker rotation. It is also found that during hot compression at higher temperatures, the softening rate of the composite decreases with increasing temperature. The predicted stress-strain behavior of the composite is approximately in agreement with the experimental results.     

Effects of particle size on residual stresses of metal matrix composites

A finite element analysis was carried out on the development of residual stresses during the cooling process from the fabrication temperature in the SiCp reinforced AI matrix composites. In the simulation, the two-dimensional and random distribution multi-particle unit cell model and plane strain conditions were used. By incorporating the Taylor-based nonlocal plasticity theory, the effect of particle size on the nature, magnitude and distribution of residual stresses of the composites was studied. The magnitude thermal-stress-induced plastic deformation during cooling was also calculated. The results show similarities in the patterns of thermal residual stress and strain distributions for all ranges of particle size. However, they show differences in magnitude of thermal residual stress as a result of strain gradient effect. The average thermal residual stress increases with decreasing particle size, and the residual plastic strain decreases with decreasing particle size.     

Effect of particle cracking on the strength and ductility of Al-SiCp powder metallurgy metal matrix composites

The effects of particle cracking on the strength and ductility of Al-SiCp metal matrix composite material (MMC) was investigated. The composite was manufactured using a simple powder metallurgy (PM) technique of hot pressing followed by hot extrusion. Also, the effects of reinforcement weight fraction and strain rate variations on the strength and ductility of the same composite were examined. It was found that particle cracking plays a significant role in controlling the mechanical properties of the composite. It was shown that particle cracking is possible in an MMC material made with a low strength matrix (commercially pure aluminum), and increases with the increase of reinforcement weight fraction, applied strain rate, and amount of plastic deformation. The yield strength increases as a function of reinforcement weight fraction and to a lesser extent as the strain rate increases. The tensile strength increases at low SiCp weight fractions, then remains constant or decreases as more particles are added to the matrix.     

Effect of deformation temperature on the mechanical behavior and deformation mechanisms of Al-Al2O3 metal matrix composites

Aluminum-alumina (Al-Al₂O₃) metal matrix composite (MMC) materials were fabricated using the powder metallurgy (PM) techniques of hot pressing followed by hot extrusion. Different reinforcement weight fractions were used, that is, 0, 2.5, 5, and 10 wt% Al₂O₃. The effect of deformation temperature was investigated through hot tensile deformation conducted at different temperatures. The microstructures of the tested specimens were also investigated to characterize the operative softening mechanisms. The yield and tensile strength of the Al-Al₂O₃ were found to improve as a function of reinforcement weight fraction. With the exception of Al-10wt%Al₂O₃, the MMC showed better strength and behavior at high temperatures than the unreinforced matrix. The uniform deformation range was found to decrease for the same reinforcement weight fraction, as a function of temperature. For the same deformation temperature, it increases as a function of reinforcement weight fraction. Both dynamic recovery and dynamic recrystallization were found to be operative in Al-Al₂O₃ MMC as a function of deformation temperature. Dynamic recovery is dominant in the lower temperature range, while dynamic recrystallization is more dominant at the higher range. The increase in reinforcement weight fraction was found to lead to early nucleation of recrystallization. No direct relationship was established as far as the number of grains nucleated due to each reinforcement particle.     

离心铸造WC颗粒增强钢基复合材料辊环的研制

介绍了WCp/钢基复合材料轧辊的材料选择和制备工艺 ,并对其显微组织及力学性能进行了分析。工业实验结果表明 :复合材料轧辊的寿命比普通Cr12轧辊高 3倍以上     

Deformation behavior of SiC particle reinforced Al matrix composites based on EMA model

Effects of the matrix properties,particle size distribution and interfacial matrix failure on the elastoplastic deformationbehavior in Al matrix composites reinforced by SiC particles with an average size of 5μm and volume fraction of 12%werequantitatively calculated by using the expanded effective assumption(EMA)model.The particle size distribution naturally bringsabout the variation of matrix properties and the interfacial matrix failure due to the presence of SiC particles.The theoretical resultscoincide well with those of the experiment.The current research indicates that the load transfer between matrix and reinforcements,grain refinement in matrix,and enhanced dislocation density originated from the thermal mismatch between SiC particles and Almatrix increase the flow stress of the composites,but the interfacial matrix failure is opposite.It also proves that the load transfer,grain refinement and dislocation strengthening are the main strengthening mechanisms,and the interfacial matrix failure and ductilefracture of matrix are the dominating fracture modes in the composites.The mechanical properties of the composites strongly dependon the metal matrix.     

铝金属基复合材料表面稀土转化膜

介绍了铝金属基复合材料的发展情况及存在的腐蚀问题,详细评述了铝金属基复合材料表面稀土转化膜在国内外的研究进展及现状,对未来这一技术的发展提出了展望。     

Microstructures and wear resistance of large WC particles reinforced surface metal matrix composites produced by plasma melt injection

Large WC particles (− 840 μm-+ 420 μm) reinforced surface metal matrix composites (SMMCs) were produced using plasma melt injection (PMI) process on a Q235 (similar to ASTM A570 Gr. A) low carbon steel substrate. Microstructures of the SMMC were observed using scanning electron microscope (SEM), and the composition was determined with energy dispersion spectroscopy (EDS). Phases were analyzed with X-ray diffraction. Micro-hardness of the SMMC was tested. Wear losses of the SMMC layer were evaluated under dry friction conditions and compared with those of the substrate material. The results show that the large WC particles are caught by crystallized metal and stay in the upper part of the SMMC layer, and there is only a little melting on the outer surface. No sinking down of WC particles occurs. The SMMC layer is well bonded to the substrate, and the interface is crack free. The wear resistance of the Q235 substrate is greatly improved with large WC particles injected.     

Cavitation-erosion mechanism of laser cladded SiC particle reinforced metal matrix composite

With 2 kW continuous wave Nd YAG laser, SiC ceramic powder was laser-cladded on the AA6061 alurniniurn alloy surface. Within the range of process parameters investigated, the parameters were optimized to produce the SiCk, reinforced metal matrix composites(MMC) modified layer on AA6061 alloy surface. After being treated, the modified layer is crack free, porosity-free, and has good metallurgical bond with the substrate. The microstructure and chemical composition of the modified layer were analyzed by such detection devices as scanning electronic microscope(SEM EDX) and X ray diffractometer(XRD). The performance of electrochemical corrosion and cavitation erosion and their mechanism were estimated by the microhardness tester, potentiostat and ultrasonicinduced cavitation device.     

激光焊接颗粒增强铝基复合材料中TiB2颗粒的演变行为（英文）

研究大功率激光器焊接TiB2颗粒增强铝基复合材料时TiB2粒子的演变行为。采用X射线衍射(XRD)、扫描电镜(SEM)及能谱(EDS)分析焊缝内粒子的物相、热力学过程及形貌特征;同时对TiB2和铝基体的界面反应进行讨论。结果表明:当TiB2团簇尺寸大于激光光斑直径时,焊缝中部的TiB2粒子会熔融在一起,较大尺寸的TiB2会发生断裂;当与铝熔体接触后,熔化后的TiB2粒子会与Al发生反应生成Al3Ti和AlB12,并且焊缝中部的界面反应比焊缝边缘的剧烈。     

The metallurgical and deformation behaviours of laminar metal matrix composites after ballistic impact

In this study, two types of laminar metal matrix composite (MMC) samples were manufactured. Their failure mechanisms and deformation behaviours were investigated to evaluate ballistic performance. These laminated samples consist of sub-MMC layers and un-reinforced Al layers. The sub-MMC layers were MMC layers produced from particulate-Al₂O₃-reinforced AA 2024 aluminium alloys. These layers were manufactured using both squeeze casting and hot pressing techniques. They were laminated with un-reinforced AA 2024 aluminium alloy layers as A-type and B-type using the same techniques. The ballistic tests were carried out with a 7.62 mm × 51 mm armour piercing (AP) projectile, and the responses of the targets to ballistic impact was evaluated by examining the hole surface generated by the projectiles. A-type and B-type laminated structures showed different failure mechanisms. Deep craters occurred on both sides of the hole of the A-type target, while for B-type targets, petalling and bulging occurred at the entrance and exit of the hole, respectively.     

Damage analysis for particle reinforced metal matrix composite by ultrasonic method

The damage characteristic of particle reinforced metal matrix composite （PMMC） was studied by ultrasonic non-destructive evaluation method. After the sample was damaged induced by tensile load, the ultrasonic wave that propagated in the sample were collected. The damage parameter was defined by ultrasonic parameter and the wave signals were analyzed by correlation method. The results show that with the increase of tensile load, the damage parameter increases and the correlation coefficient decreases. The fracture section morphologies of PMMC under tensile load were observed by SEM. It is found that there are many concaves in the metal matrix. Therefore the damage evolution can be concluded. The initial damage is induced by void nucleation, growth and subsequent coalescence in the matrix or interface separation.     

35% SiC_p/2024A1复合材料的热变形行为(英文)

采用Gleeble-1500D热模拟试验机,对35%SiCp/2024A1复合材料在温度350~500°C、应变速率0.01~10s-1的条件下进行热压缩试验,研究该复合材料的热变形行为与热加工特征,建立热变形本构方程和加工图。结果表明,35%SiCp/2024A1复合材料的流变应力随着温度的升高而降低,随着应变速率的增大而升高,说明该复合材料是正应变速率敏感材料,其热压缩变形时的流变应力可采用Zener-Hollomon参数的双曲正弦形式来描述;在本实验条件下平均热变形激活能为225.4 kJ/mol。为了证实其潜在的可加工性,对加工图中的稳定区和失稳区进行标识,并通过微观组织得到验证。综合考虑热加工图和显微组织,得到变形温度500°C、应变速率0.1~1 s-1是复合材料适宜的热变形条件。     

碳颗粒尺寸对自发渗透原位制备TiCp/Mg微观组织的影响

利用原位反应自发渗透技术制备了组织均匀且致密度高的TiCp/Mg复合材料, 研究了原位反应温度以及碳颗粒尺寸对制备的TiCp/Mg复合材料微观组织的影响.结果表明: 当使用大尺寸碳粒子(≤100μm)时, 随着反应温度的提高, 原位生成物TiCp的含量增加, 但有残留反应物Ti和C的存在; 碳粒子尺寸减小(≤30μm)时, 原位反应较完全, 不再有残留物存在; 原位反应产物组织中, 增强相TiCp主要呈互穿网络状、颗粒状以及片状等形态; 增强相的尺寸随碳粒子尺寸的减小而减小, 在碳颗粒尺寸为1.5μm时TiC更易呈现等轴颗粒状, 尺寸约为0.5～2.0μm.     

Microstructure of in-situ TiC particle reinforced titanium alloy matrix composites

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金属基复合材料的分类及制造技术研究进展

研究金属基复合新材料是当代新材料技术领域中的重要内容之一.金属基复合材料具有高比强度、高比模量、较好的耐热性和更低的热膨胀系数等优点,针对金属基复合材料的制备工艺不完善、成本高、难形成大规模的生产等弱点,并结合国内外相关工作的研究状况,从金属基复合材料的分类、性能特点以及制成品的制备技术与应用方面,对其领域内取得的研究...     

Thermal residual stresses and stress distributions under tensile and compressive loadings of short fiber reinforced metal matrix composites

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