无压浸渗制备SiC_p/Al复合材料的力学性能研究

采用无压浸渗法制备出不同SiC粒度组成和硅含量的SiCp/Al复合材料,并对其性能进行测试分析。研究结果表明:SiCp/Al-7Si复合材料硬度比SiCp/Al-12Si复合材料的低,但抗弯强度和断裂韧性比SiCp/Al-12Si复合材料的高,对不同SiCp/Al复合材料的力学性能的影响程度各不相同;粒径小的SiC颗粒有利于SiCp/Al复合材料的硬度、抗弯强度和断裂韧性的提高。当SiC粒度为W7,铝合金中Si含量(质量分数)为7%时,SiCp/Al复合材料的抗弯强度为502MPa、断裂韧性为7.1MPa·m1/2、硬度为66HRA。     

SiCq对6066铝合金破坏机制及阻尼性的影响

研究了粉末冶金法制备6066铝合金及增强相SiCp(尺寸3μm）含量为7％，12％（体积）的6066铝合金复合材料的拉伸断口及阻尼特性。复合材料的阴尼性能通过动态机械热分析仪测量，得出了增强相SiCp体积分数不同的两个6066Al/SiCp复合材料及6066铝合金在1Hz及30－250℃的温度范围的阴尼温度关系。结果表明，当增强相含量体积为7％时，SiCp颗粒分布均匀，与基体结合良好，复合材料的破坏归因为增强相周围的铝基体产生孔洞形核、长大、聚合引起的；增强相体积含量为12％时，SiCp聚集成团，复合材料的破坏则归因为SiCp团块形成裂纹而断袭。少量SiCp(7%）明显提高6066Al合金阻尼性能，尤其是高温阻尼性能。但SiCp含量再增加到12％没有效果，6066Al/SiCp复合材料的高阻尼性能主要是因为SiCp颗粒加入后增加的高密度位错及基体与SiCp颗粒的界面消耗能量。     

SiCp/Al复合材料制备工艺对组织与性能的影响

采用高能球磨粉末冶金法制备了体积分数为15％SiCp／2009Al复合材料，研究了球磨转速、球磨时间对复合材料组织和性能的影响。结果表明，球磨转速和球磨时间是影响复合材料力学性能的重要因素，较长时间高转速球磨使得SiC颗粒均匀分布，转速190r／min、球磨6h制备的复合粉末经真空热压、挤压后的复合材料SiC颗粒均匀分布，材料的抗拉强度高达650MPa，伸长率大于5％。     

用反应压力熔渗法制备高含量SiCp/6013Al复合材料及其力学性能

研究了反应压力熔渗法制备高含量SiCp／Al复合材料的工艺过程及其抗弯强度。研究表明：通过适当的粒度配比,可在低温、低压力下熔渗制备组织均匀的高含量SiCp／6013Al复合材料,SiC颗粒含量达到63％;复合材料的强度在很大程度上依赖于SiC颗粒尺寸及界面反应程度,合适的界面结合及细SiC颗粒的掺入有利于复合材料强度的提高,最高可达445MPa。     

高硅铝合金及颗粒增强铝基复合材料组织性能的探究

采用真空热压烧结工艺制备Al-30Si合金、30%Sip/Al、30%SiCp/2024Al、30%SiCp/6061Al(均为体积分数)复合材料,测定其热膨胀系数及力学性能。利用扫描电镜(SEM)、能谱仪(EDS)对其微观组织结构及断口形貌进行表征,探究了高硅铝合金及颗粒增强铝基复合材料的组织与性能,分析了材料的断裂机制。结果表明:SiCp/2024Al复合材料中SiC颗粒分布均匀,组织致密,综合性能好,热膨胀系数(CTE)为13.69×10-6/K,硬度达到134 HB,极限抗拉强度达353 MPa。SiCp/6061Al复合材料中SiC颗粒分布较均匀,界面结合较好,组织不够致密,有少许孔隙,性能较好。SiCp/6061Al和SiCp/2024Al复合材料的断裂方式都是界面基体的撕裂结合SiC颗粒的断裂。Sip/Al复合材料中Si颗粒分布较均匀,断裂方式为界面脱开,性能较差。Al-30Si合金在烧结过程中形成大量板条状的Si相,性能最差,断裂方式以合金撕裂为主。     

固溶时效对高体积比SiCp/6013Al复合材料导热性能及强度的影响

研究了固溶时效对高体积比SiCp/Al复合材料的导热性能及抗弯强度影响.研究发现热处理改变了复合材料SiCp/Al 界面结合状况,提高了导热性能;同时强化了基体合金,改变了SiCp 颗粒所受应力状态,提高了复合材料的强度,使高体积比SiCp/Al复合材料的导热系数达到210 W/(m*K),抗弯强度达到519 MPa.     

SiCp／2024Al铝基复合材料的腐蚀及防护

用电化学方法研究了2024Al和SiCp/2024Al基复合材料在3．5％NaCl水溶液中的耐蚀性,用电化学阻抗技术对它们的硫酸阳性氧化膜的耐蚀性进行了研究,结果表明,SiCp/2024Al复合材料在3．5％NaCl水溶液中比相应的基体金属有较大的腐蚀敏感性,SiCp/2024Al的阳极氧化膜具有良好的耐NaCl溶液腐蚀能力,但其耐蚀性不如2024Al合金的阳极氧化膜,这是由于氧化膜中SiC颗粒的存在破坏了氧化膜的完整性和均匀性所致。     

SiCp/2014Al复合材料的热变形行为及本构模型

在Gleeble-3180热模拟机上对碳化硅颗粒增强铝基(SiCp/2014Al)复合材料进行热压缩试验,研究其在变形温度为350,400,450 ℃和500 ℃,应变速率为0.001,0.01,0.1s-1和1.0 s-1条件下的热变形行为。根据热压缩实验的真应变-真应力数据,在考虑应变、应变速率和变形温度对流动应力的耦合影响下构建修正的Johnson-Cook(JC)本构模型,同时建立人工神经网络模型(ANN)。结果表明:SiCp/2014Al复合材料的流变应力随应变速率的增加和温度的降低而增大。与修正的JC模型相比,ANN模型具有较低的均方根误差(0.51 MPa)和平均绝对误差(1.43%),以及较高的相关系数(0.999 7),表明其对SiCp/2014Al复合材料热变形流变应力的预测具有更高的预测精度和可靠性。      

冷热循环对粉末冶金SiCp/Al复合材料力学性能的影响

采用粉末冶金制备了15％（体积分数）SiCp/Al复合材料，研究了不同冷热循环工艺对复合材料力学性能的影响。结果表明，上限温度在175℃以下的冷热循环对复合材料的屈服强度和抗拉强度影响不大，当上限温度达到200℃后复合材料的屈服强度提高了80MPa，抗拉强度则基本不变。复合材料的屈服强度的提高主要是由于材料在冷热循环的高温过程中基体中的G．P区转变成了过渡相口”。断口观察表明，经过不同冷热循环工艺处理后，复合材料的断裂形式大致相同，即除了基体断裂外，还存在SiC颗粒开裂的情况。冷热循环对复合材料的延伸率影响不明显。     

自蔓延反应涂层法制备SiCp/Al复合材料及性能

对采用铝浴自蔓延反应涂层制备SiCp/Al复合材料的反应机理及与组织演变研究发现：在SiCp/Al表面形成TiC和Ti5Si3复合涂层，显著改善了SiCp与铝液的润湿性，凝固后的SiCp/Al复合材料经热挤压可进一步改善界面状态和界面结合。对它的力学性能和摩擦磨损性能研究表明：由于SiCp的加入对弹性模量的影响与其它方法制备的SiCp/Al复合材料相同，因此可通过降低反应程序，以便提高材料的力学性能。SiSp/Al复合材料摩擦性能主要取决于SiC颗粒的粒度及含量。     

陶瓷颗粒增强粉末冶金Fe-2Cu-0.6C复合材料的微观结构和力学性能

采用传统粉末冶金压制/烧结技术，经600 MPa压制、1140℃烧结制备了陶瓷颗粒增强（SiC、TiC及TiB₂陶瓷颗粒，质量分数0~1.6%）Fe-2Cu-0.6C低合金钢复合材料，对三种复合材料的微观结构和力学性能进行了研究。结果表明:在烧结过程中，SiC与TiB₂颗粒与基体发生反应，故而与基体界面结合良好；当添加质量分数为1.6%的SiC颗粒时，复合材料烧结后的布氏硬度与抗拉强度分别比基体提高了35.9%、69.4%；添加质量分数为1.2%的TiB₂颗粒时，复合材料相对密度比基体提高了5.3%，其烧结硬度、抗拉强度与基体相比分别提高了77.9%、72.6%；由于烧结过程中TiC颗粒不与基体发生反应，故而添加TiC颗粒对复合材料的布氏硬度、抗拉强度影响不大。     

机械合金化制备SiC弥散强化铜基复合材料

用机械合金化(MA)制备了一种以SiC为增强相的Cu／sic复合材料,研究了机械合金化过程中SIC颗粒形貌、尺寸的变化,以及增强相的含量对复合材料抗拉强度、硬度、相对电导率及显微结构的影响。结果表明,Sic对于铜是一种有效的增强相,当SiC的质量百分含量为1％时,强化效果较佳,抗拉强度可达391MPa,相对电导率为50．2％,性能较优。     

镁锂基复合材料界面结构及热力学分析

制备了碳纤维及ＳｉＣ晶须增强的Ｍｇ８Ｌｉ１Ａｌ基复合材料。利用透射电镜,高分辨电子显微镜研究了Ｍｇ８Ｌｉ１Ａｌ／ＳｉＣｗ复合材料的界面结构,发现ＳｉＣ晶须与基体合金界面结合良好,没有明显的反应物。     

粉末冶金制备SiC/6061Al复合材料的显微组织和力学性能研究

采用粉末冶金法制备了体积分数为35%的SiC_p/6061Al基复合材料,研究了复合材料的显微组织和基体与增强体颗粒界面对复合材料力学性能的影响。结果表明:SiC颗粒在基体中分布均匀,基体与增强体之间的界面结合情况较好,复合材料致密度高,抗拉强度较高。     

不同陶瓷颗粒增强铁基复合材料力学性能的研究(英文)

Mechanical properties of iron matrix composites reinforced by different types of ceramic particles(SiC,Cr3C2,TiC and Ti(C,N)) prepared by the two-stage resistance sintering were studied experimentally.It was found that tensile strength of SiC/Fe composite shows the highest among the four types of composites.The elongation of all the composites decreases as increasing of reinforcement volume fraction.The stress-strain curves of the composites were simulated by Eshelby approach modeling to reveal the strengthening mechanisms.The modeling and microstructure observations suggest that the strengthening mechanism of the iron matrix composites relies not only on load sharing of the reinforcements but also on reinforcement increasing matrix strength.     

Study of Tribological and Mechanical Properties of A356–Nano SiC Composites

In the present investigation, the microstructural, wear, tensile and compressive properties of Al?C7Si alloy matrix nano composites have been discussed. It is noted that the composites contain higher porosity level in comparison to the matrix and increasing amount of porosity is observed with the increasing volume fraction of the reinforcement phase in the matrix. The wear sliding test disclosed that the wear resistance of the nano SiC reinforced composites is higher than that of the unreinforced alloy. It is believed that the presence of SiC particles could shield the matrix and silicon phase from directly experiencing the applied load from the counterface. It was revealed that the presence of nano-SiC reinforcement also enhanced the hardness, tensile and compressive yield strength of Al?C7Si alloy which can be attributed to small particle size and good distribution of the SiC particles and grain refinement of the matrix. The highest yield strength and UTS was obtained by the composite with 3.5?vol% SiC nano-particles. The results show that the addition of nano-particles reduces the elongation of A356 alloy.     

Effect of overaging and particle size on tensile deformation and fracture of particle-reinforced aluminum matrix composites

The effect of reinforcement particle size and overaging treatment on the tensile behavior and fracture morphology of a 2080/SiC/20 _p composite was investigated. Tensile behavior was profoundly influenced by particle size and matrix strength. The composite strength increased with a decrease in particle size, while overaging greatly reduced the strength of the composite, independent of particle size. Almost all particles on the fracture plane were fractured, and the amount of particle fracture in the composites was insensitive to overaging and particle size, due to the excellent bonding between SiC particles and the Al matrix. Fractography showed that void nucleation in the matrix of peak-aged composites took place primarily at very fine SiC particles, which were much smaller than the average SiC particle size. Subsequent failure took place by the tearing topography surface (TTS) mechanism. In the overaged composite, composites failed by a more conventional void nucleation and growth process, where void nucleation took place at coarsened S precipitate particles, resulting in smaller and more elongated voids.     

陶瓷颗粒增强扩散合金化钢复合材料的微观结构和力学性能

采用传统粉末冶金工艺制备了陶瓷颗粒增强Fe?0.5Mo?1.75Ni?1.5Cu?0.7C扩散合金化钢复合材料,选用的陶瓷颗粒为SiC、TiC和TiB₂。采用光学显微镜和扫描电子显微镜观察了烧结材料微观结构,并对烧结材料的硬度、强度和摩擦磨损性能进行了测试。结果表明,由于SiC和TiB₂与基体的化学相容性好,陶瓷颗粒与基体界面结合良好;由于TiC颗粒具有极高的化学稳定性,TiC颗粒与基体界面结合情况不理想。随着陶瓷相含量（质量分数）的增加,添加SiC和TiC的烧结试样相对密度降低;添加TiB₂的烧结试样相对密度先增加后降低,当添加TiB₂质量分数为0.9%时达到最大值。随着陶瓷含量增加,添加SiC和TiB₂烧结试样的硬度增大,当陶瓷相质量分数超过1.2%时,硬度增加缓慢;添加TiC烧结试样的硬度先增加后降低,当添加TiC质量分数为0.9%时达到最大值。随着陶瓷相含量增加,添加SiC和TiC烧结试样的强度降低,少量添加SiC对强度没有明显损害;添加TiB₂烧结试样的强度先增加后降低,当添加TiB₂质量分数为0.6%时达到最大值（971.7MPa）,比基体提高了14.1%以上。添加陶瓷相对烧结钢性能的积极影响依次是TiB₂、SiC和TiC。     

Mechanical properties of 2014Al/SiC composites with oxidized SiC particles

Metal-matrix composites (MMCs) are known to have wide applications in parts of transportation devices such as automobiles and aircraft. Al-matrix composites using SiC particles as reinforcements are especially spotlighted because of their low cost, superior specific modulus, specific strength, wear resistance, and high-temperature stability. However, Al₄C₃ formed by the interfacial reaction between Al and SiC weakens the interfacial bonding strength. It is also known to be unstable in the water-soluble atmosphere. In this study, the passive oxidation of SiC powder is used as a protective layer against the reaction between the Al matrix and the SiC particles. We investigated the changes in interfacial product of the composites, and mechanical properties such as interfacial bonding strength and tensile strength, in terms of the oxidized-layer thickness of the reinforcement.     

Tensile properties of short fiber-reinforced SiC/Ai composites: Part I. effects of matrix precipitates

The tensile behavior of aluminum matrix composites reinforced with 8 and 20 pet SiC whiskers or paniculate was characterized. Two matrix alloys were employed, a solution-hardened Al-Mg alloy (5456) and a precipitation-hardened Al-Cu-Mg alloy (2124). The precipitation-hardened alloy was aged to develop a variety of precipitate microstructures. It was found that additions of SiC caused monotonie increases in the elastic modulus, 0.2 pct offset yield stress, work-hardening rate, and ultimate tensile stress. The proportional limit, however, was found to first decrease and then increase with SiC content. Whiskers caused a greater increase in the longitudinal elastic modulus than particles. For the 2124 alloy, it was found that the proportional limit could be varied between 60 and 650 MPa by changing the precipitate microstructure, while changes in the SiC content had much smaller effects. These observations are discussed in relation to current theories of the strengthening of short fiber composites, with primary emphasis being placed on the effects of SiC additions on the elastic modulus and the work-hardening rate.