共查询到18条相似文献,搜索用时 78 毫秒
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利用机械合金化法(MA)、磁力搅拌法(MS)、放电等离子烧结工艺(SPS)制备材料样品,研究了Al2O3含量对碳纳米管(CNTs)增强Cu基复合材料性能的影响。结果表明,加入Al2O3与碳纳米管增强相后的Cu基复合材料与纯Cu相比,磨损率降低了70.9%~85.7%,维氏硬度提高了11.6%~24.5%。当添加1.0%CNTs和1.6%Al2O3(质量分数)时所制备的复合材料的综合性能最优:相对密度为97.5%,维氏硬度为75.2 HV,热导率为272.45 W/(m·K),电导率为4.39×107Ω-1·m-1。 相似文献
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研究了拉拔形变率对Al_2O_3颗粒增强Cu基复合材料组织和硬度演变规律的影响。结果表明:基体中弥散分布着高体积分数的球状纳米级Al_2O_3强化相粒子,尺寸为30~60 nm;经拉拔处理后组织形变量增加,晶粒中生成了位错缠结界面以及带状组织。随着拉拔形变率增加,平行于拉拔方向的晶粒发生明显拉长,晶粒的长宽比也明显增大。Al_2O_3颗粒增强Cu基复合材料在拉拔过程中会产生加工硬化现象,基体中产生大量位错,弥散态Al_2O_3强化相颗粒会对这些位错产生显著钉扎效果,进而抑制了基体位错的运动。 相似文献
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Al_3Ti颗粒增强镁基复合材料的反应烧结 总被引:1,自引:1,他引:0
采用Mg-Al-Ti反应体系,反应烧结制备了Al_3Ti颗粒增强镁基复合材料,研究了烧结工艺对Al_3Ti/Mg复合材料的组织和密度的影响.研究结果表明:采用镁、铝和钛粉反应烧结可以获得致密的Al_3Ti/Mg复合材料,Al_3Ti为原位形成,呈直径为0.5~5μm颗粒状较均匀地分布在镁基体中.烧结工艺(温度和保温时间)对Al_3Ti/Mg复合材料的组织和密度有着明显的影响,随着温度升高和保温时间延长,原位反应越完全,有利于Al_3Ti颗粒的分散,但过高温度和保温时间的延长,将造成颗粒的再团聚和镁的烧损.Al_3Ti/Mg复合材料较佳的烧结工艺参数为:温度750~800℃,保温时间90~120min. 相似文献
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颗粒增强铝基复合材料疲劳断裂研究 总被引:1,自引:0,他引:1
对粉末冶金法制备的碳化硅颗粒增强铝基复合材料进行了旋转弯曲疲劳试验研究。采用金相显微镜和扫描电镜分别观察了疲劳试验后复合材料纵向显微组织和疲劳断口。通过金相显微镜,观察了增强体颗粒在疲劳循环应力水平下可能的损伤形式。通过疲劳断口观察,分析了断面上不同区域的疲劳裂纹传播特征。结果表明,增强体的加入有效地提高了复合材料的屈服强度、弹性模量和疲劳性能,使复合材料高周疲劳极限提高到约250MPa(1×10^7循环周次)。复合材料的疲劳损伤随机分布于试样内。断口分析还表明复合材料疲劳同样遵循裂纹萌生,长大,失稳断裂规律,其裂纹起源于铝基体内。加入SiC颗粒减弱或遮盖了疲劳裂纹传播时的晶体学特征,使得复合材料高周疲劳断面没有发现常见的疲劳辉纹。 相似文献
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采用高能球磨结合放电等离子烧结的方法制备0.5%、1.0%和2.0%的Al_2O_3弥散增强Cu基复合材料。研究Al_2O_3在Cu基体中的分布状态,以及对复合材料强度、硬度、导电性能和摩擦系数的影响。结果表明:弥散分布于晶界处的Al_2O_3颗粒导致复合材料的硬度和抗拉强度都提高,而伸长率、电导率降低和摩擦系数降低。1.0%Al_2O_3/Cu复合材料的相对密度达到98.22%、电导率为48.38 MS/m,硬度102.7 HV,抗拉强度264.97 MPa,摩擦系数0.28。 相似文献
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李振华鲁冰沈铁军董建光傅珠荣 《世界有色金属》2023,(22):53-55
研究了Al_(2)O_(3)粉体增强3003铝合金在不同磨粒粒径与冲蚀速度下的冲蚀磨损行为,探索了该合金与3003合金的冲蚀失效规律及其微观磨损机制。结果表明:在相同冲蚀磨损条件下,添加1%氧化铝粉体的3003合金冲蚀磨损速度比3003合金下降~20%;两种材料在8m/s冲蚀速度下的冲蚀磨损失重率是4m/s冲刷速度下的2~2.5倍,但随着冲蚀速度进一步增加,添加1%氧化铝粉体的3003合金冲蚀磨损失重率反倒有所增加;两种材料冲蚀磨损失重率随着磨粒粒径的增大呈现先增大后减小的变化趋势,磨粒粒径分布在0.053mm~0.106mm时两种材料失重率出现极大值。 相似文献
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BAOChonggao WANGEn-ze GAOYi-min XINGJian-dong 《钢铁研究学报(英文版)》2005,12(2):60-63
Inpreviouswork,heat resistingsteelwithlow carboncontentandhighoxidationresistanceatele vatedtemperaturewastakenasthematrixmaterial. AndAl2O3ceramicparticleswereutilizedasrein forcedphasefortheirgreatstabilityandhighrigidi tyatelevatedtemperature.Inorde… 相似文献
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为了研究铜元素含量变化对复合材料界面反应、微观组织结构和机械性能的影响,利用挤压铸造法制备了体积分数均为40%的Al2O3纤维增强纯铝和Al—Cu合金(1%,3%和5%)复合材料。采用X射线、TEM、SEM和拉伸实验手段,观察和测试了4种复合材料的微观组织和机械性能。结果表明,Al2O3纤维表面含有非晶SiO2成分,在高应力下易于开裂。铜元素的加入对材料的析出产生和机械性能有重要影响。铜元素引入后在复合材料中纤维表面处偏聚和富集,促进了界面θ相析出,并随基体中Cu含量提高而增加。当铜含量增加到5%后,基体内部也出现明显的析出相。拉伸实验结果表明随着Cu含量的增加复合材料的抗拉强度增高,Al2O3f/Al-Cu与Al2O3f/纯Al相比,抗拉强度分别增加了102%,146%和171%。SEM断口观察表明:基体合金的断口基本上都呈宏观脆性断口,具有低的展延性和撕裂纹理;大量的纤维从复合材料基体中拔出,一些纤维被拉断,这些特点与界面结合物和多晶的Al2O3纤维结构密切相关。 相似文献
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Sung Wan Kim Won Sub Chung Kee-Sun Sohn Chang-Young Son Sunghak Lee 《Metallurgical and Materials Transactions A》2010,41(2):380-388
Alumina matrix composites reinforced with carbon nanotubes (CNTs) fabricated by CNT purification, mixing, compaction, and
sintering processes, and the effects of the CNT addition on wear resistance were investigated in relation to the relative
density, hardness, and fracture toughness. Wear resistance and fracture toughness were measured by the dry sliding wear test
method and the indentation fracture test method, respectively. Zero to ~3 vol pct of CNTs were homogeneously distributed in
the composites, although some pores existed. The wear resistance and fracture toughness increased with an increasing CNT fraction,
but the composite specimen containing 3.0 vol pct of CNTs hardly showed an increase over the specimen containing 2.25 vol pct
of CNTs. Observations of worn surfaces revealed that the wear mechanism involved both the abrasive and delamination wear modes
in the specimens containing 0 to ~0.75 vol pct of CNTs, whereas the surface was worn largely in an abrasive wear mode in the
specimens containing 1.5 to ~3.0 vol pct of CNTs. This was because CNTs helped to change the delamination wear mode to the
abrasive wear mode by preventing crack initiation and propagation at alumina grains. The fracture toughness increase provided
beneficial effects in the resistance to crack initiation and propagation, the reduction in delamination wear on the worn surface,
and the consequent improvement in wear resistance. Because the effect of the porosity increase due to the CNT addition unfavorably
affected the improvement of wear resistance and fracture toughness in the specimen containing 3.0 vol pct of CNTs, the appropriate
level of CNT fraction was 1.5 to ~2.25 vol pct. 相似文献
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《Canadian Metallurgical Quarterly》2013,52(2):245-254
AbstractDiscontinuously reinforced metal matrix composites (DRMMCs) based on aluminum alloys are fast becoming the materials of choice in many structural and non-structural applications. They have the unique combination of strength, stiffness, coefficient of thermal expansion and affordability as well as the capability to be manufactured by conventional metal processing methods. The most notable production applications are found in the aerospace, automobile, electronics and sports equipment industries. Despite the great potential possessed by MMCs, there are still some concerns regarding the effect of the reinforcements, which are mostly ceramics, on the properties of the matrix alloys. Among these is the thermal shock resistance of the matrix material.Some of the applications in which DRMMCs are bound to find themselves will inevitably involve an element of thermal cycling where components will be subjected to rapidly changing stress states and thus thermal shock damage. In the present study, the thermal shock behaviour of 2618 Al alloy and its composite containing 10 vol.% Al2O3 particles was investigated using hardness measurements, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Under cyclic thermal shock conditions, the matrix alloy failed by matrix cracking at the surface, whereas the reinforcing Al2O3 particles simply shattered. Also, thermal shock treatment affected the precipitation kinetics and the volume fraction of the precipitate phases formed in both materials.Les composites à matrice métallique à renforcement discontinu (CMMRDs) basés sur les alliages d'aluminium deviennent rapidement les matériaux de choix de plusieurs applications structurales et non-structurales. Ils ont une combinaison unique de résistance, de rigidité, de coefficient d'expansion thermique, de bas prix ainsi que la capacité d'être fabriqués par des méthodes conventionnelles de traitement du métal. Les applications les plus remarquables en production se trouvent au niveau des industries de l'aérospatial, de l'automobile, de l'électronique et d'équipement de sports. En dépit de l'énorme potentiel des CMMRDs, il y a encore des inquiétudes en ce qui a trait à l'effet des renforcements, qui sont principalement des céramiques, sur les propriétés des alliages de la matrice. Parmi celles-ci, on trouve la résistance aux chocs thermiques du matériel de la matrice.Dans certaines applications, on trouve inévitablement un élément de cycle thermique où les composantes sont exposées à des états de contrainte changeant rapidement et, par conséquent, à un endommagement par choc thermique. Dans cette étude, on a étudié le comportement de choc thermique de l'alliage d'aluminium 2618 et de son composite contenant 10% en volume de particules d'Al2O3. On a utilisé les mesures de dureté, la microscopie électronique à balayage (SEM) ainsi que la calorimétrie par analyse différentielle (DSC). Sous conditions de choc thermique cyclique, l'alliage de la matrice a fait défaut par fissuration de la matrice à la surface alors que les particules de renforcement d'Al2O3 se sont simplement brisées en éclats. Le traitement de choc thermique a également affecté la cinétique de précipitation et la fraction volumique des phases de précipité formées dans les deux matériaux. 相似文献
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Powder Metallurgy and Metal Ceramics - The conversion into the desired shape of the metal powders using Powder Metallurgy (PM) method enables economically mass productions. This case allows... 相似文献
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《中国稀土学报(英文版)》2007
ZrO2 containing 2% (mol fraction) Y2O3 and 3% (mol fraction) Y2O3 were added into Al2O3 matrix, compositing composites with 15% volume fraction of addictives mentioned above. The testing of property and analysis of SEM presented that, after vacuum sintering at 1550 °C, thermal shock resistance of two composites was superior to Al2O3 ceramic. The experiment showed that the properties of Al2O3 composites was higher than Al2O3 ceramic, and Al2O3/ZrO2(3Y) was higher than Al2O3/ZrO2(2Y) in thermal shock resistance. Improvement of thermal shock resistance of composites was attributed to many toughness machanisms of ZrO2(Y2O3). By calculation, the fracture energy of Al2O3, Al2O3/ZrO2 (2Y) and Al2O3/ZrO2(3Y) was 38100.8 and 126.2 J·m−2, respectively. Cracks initiation resistance (R') of Al2O3/ZrO2(3Y) and Al2O3/ZrO2(2Y) was higher than Al2O3 ceramic by 1.57 and 1.41 time, respectively, and cracks propagation resistance (R″″) was higher than Al2O3 ceramic by 1.46 and 1.38 time, respectively, which was corresponding to the results of residual strength. 相似文献
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提出通过基体合金化改善Al2O3(sf)/Al界面浸润性的想法,添加的合金元素M须满足以下两个条件:(1)元素M的表面能必须小于Al的,即ΓM<ΓAl;(2)元素M的氧化物生成Gibbs自由能要小于氧化铝的。试验证明,元素镁是一种良好的润湿增强剂,稀土元素镧可在镁的基础上进一步增强润湿,但未发现其在界面上生成任何反应产物。 相似文献