碳纤维含量对Al2O3+C/ZL109混杂复合材料摩擦磨损性能的影响

利用挤压铸造法制备了A1203 C／ZLl09短纤维混杂金属基复合材料，并探讨了A1203纤维体积分数为12％时，C纤维含量对该混杂复合材料摩擦磨损性能的影响。结果表明：随着C纤维体积分数的增加，复合材料的摩擦因数和磨损率逐渐降低。12％A1203和4％C短纤维的协同作用使复合材料从轻微磨损到急剧磨损的临界转变载荷比基体合金提高了1倍。当载荷低于临界载荷时，复合材料的主要磨损机制为犁沟磨损和层离，C纤维的加入有利于磨损表面裂纹尺寸的减小。但随着载荷的逐渐增加并发生严重磨损时，基体和复合材料的磨损机制均为严重的粘着磨损甚至局部熔化磨损。     

Al含量对Fe3Al金属间化合物耐磨性的影响

采用机械合金化和热压烧结法制备了不同Al含量的Fe3Al金属间化合物块体材料,室温下在M-2000磨损试验机上进行了不同载荷和距离的干摩擦磨损试验,利用SEM观察试样磨损后的表面形貌,对其耐磨性能和磨损机理进行了研究.结果表明,Al含量对热压烧结Fe3Al的耐磨性能有显著影响.除Fe-30Al外,Al含量越高,耐磨性越好,其中Fe-32Al的磨损量大幅度下降,而Fe-30Al出现反常.不同Al含量的Fe3Al块体材料的耐磨性与其力学性能密切相关.不同载荷下Fe3Al块体材料的磨损机制有着明显差异:低载荷下磨损表面发生塑性变形,磨损形式是以磨粒磨损为主的微切削和微犁沟;而在高载荷下,应力集中产生裂纹并迅速扩展,最终导致疲劳断裂,以片层状剥落为主要特征.     

ZL109铝合金及其复合材料干滑动磨损表面及亚表面的观察与分析

利用预制体挤压浸渗法分别制备了Al2O3或C短纤维单一增强以及两者混杂增强ZL109金属基复合材料，探讨了基体合金及其复合材料的干滑动摩擦磨损行为，并对其磨损表面及亚表面形貌进行了观察和分析。结果表明：C纤维在复合材料中起到一定的自润滑作用，Al2O3和C短纤维混杂增强复合材料的磨损率低于基体合金和单一纤维增强的复合材料。与基体相比，单一Al2O3增强复合材料从轻微磨损到急剧磨损的临界转变载荷明显提高，经C纤维混杂后，其临界载荷进一步提高。经磨损表面及亚表面的观察与分析表明：纤维增强对基体合金的磨损机制没有明显影响，在轻微磨损阶段，主要磨损机制为犁沟磨损和层离，亚表面分为3个区域：表层未脱落的剥离层、亚表面裂纹形成区以及未受影响区。发生严重磨损时，磨损机制转变为严重的粘着磨损，此时表层未脱落的剥离层遭到破坏。     

(TiB2+Al3Ti)/Al-4.5Cu原位复合材料的高温耐磨性能

本文采用混合盐法制备了(TiB2 Al3Ti)/Al4.5Cu原位复合材料,研究了该复合材料在150℃下的干摩擦滑动磨损行为,并与基体合金进行对比.结果表明,载荷在10～20 N之间时,(TiB2 Al3Ti)/Al-4.5Cu原位复合材料的磨损量低于基体合金,但并不明显;随载荷的增加(特别是当载荷超过30 N之后),复合材料的磨损量仍低于基体合金,且复合材料的磨损量增大的速度小于基体合金磨损量的增长速度.(TiB3 Al3Ti)/Al-4.5 Cu原位复合材料同45钢对磨时的主要磨损机制为粘着磨损和磨粒磨损.随着原位反应体系中混合盐含量的增加,复合材料的耐磨性能提高,并逐渐由粘着磨损向磨粒磨损过渡.     

混杂比对AZ91D纳米复合材料油润滑摩擦磨损行为的影响（英文）

使用MRS-10P型四球摩擦试验机对AZ91D镁合金及不同混杂比碳纳米管和纳米碳化硅增强AZ91D镁合金复合材料在油润滑条件下的摩擦磨损行为进行研究。在加载载荷为200~1000 N、主轴转速为380 r/min时测试AZ91D及其复合材料的摩擦因数和磨损率,采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)和能谱分析仪(EDS)分析磨损表面形貌、相和元素组成,并讨论碳纳米管和纳米碳化硅的协同作用机制。结果表明,与AZ91D镁合金相比,由少量碳纳米管和纳米碳化硅混杂增强的AZ91D镁基纳米复合材料具有更好的耐磨性能和不同的磨损机理,质量分数分别为0.5%的碳纳米管和纳米碳化硅增强的AZ91D镁合金基纳米复合材料具有最好的摩擦性能。镁基混杂纳米复合材料的磨损机理为微犁沟、微切削、轻微磨粒及脱粘磨损的复合形式。     

粉煤灰/铝-镁合金复合材料的微观组织及摩擦磨损性能

采用粉末冶金法制得粉煤灰/Al-25%Mg复合材料,研究不同粉煤灰含量对复合材料微观组织、硬度和摩擦磨损性能的影响,采用扫描电子显微镜观察复合材料的磨损表面形貌,并对其磨损机制进行探讨。结果表明:随着粉煤灰含量的增加,复合材料的硬度呈现先增大而后减小的趋势;在较低粉煤灰含量和较低载荷下,该复合材料的摩擦因数均低于基体铝合金的,并且随粉煤灰含量的增加复合材料的耐磨性有所提高,复合材料的磨损机制主要为粘着磨损和磨粒磨损;在较高粉煤灰含量和较高载荷下,该复合材料的磨损机制转化为以剥层磨损和磨粒磨损为主。     

Yb添加量对非晶态化学镀Ni-Yb-P镀层耐磨性能的影响

采用化学镀方法制备了非晶态Ni-P和Ni-Yb-P镀层,研究了稀土元素Yb添加量对镀层硬度和耐磨性能的影响。结果表明,Ni-Yb-P镀层的硬度随着Yb添加量的增加而提高,当镀液中YbN3O9.5H2O的添加量为200mg/L时,镀态下镀层的耐磨性能最佳。磨损试验发现,镀态下非晶态Ni-P镀层的磨损机制为粘着磨损和犁削磨损,其耐磨性能较差;随着稀土添加量的增加,镀层耐磨性能提高,但稀土添加量过高时,镀层耐磨性能又会下降。     

原位自生钢基复合材料耐磨性能的研究

用铸造的方法制备了原位自生复合碳化物[(Ti,W,Cr,V,Nb)C]增强钢基复合材料,并对该复合材料的磨粒磨损性能及磨损机理进行了研究。结果表明,采用该方法制备的钢基自生复合材料中,自生碳化物颗粒细小、圆整、且分布均匀,碳化物颗粒增强相体积分数达到42.8%;原位自生钢基复合材料的耐磨性能优良。在磨粒磨损条件下,其磨损机制主要是显微切削、颗粒脱落和脆性剥落;稀土和合金元素能够提高原位自生钢基复合材料的耐磨性能。     

TiB_2+TiC含量对等离子熔覆Ni55基复合材料涂层显微组织及耐磨性能的影响（英文）

采用等离子熔覆工艺,以不同比例的Ti、B_4C和Ni55为原料原位制备TiB_2-TiC强化Ni55基复合材料涂层,研究陶瓷相TiB_2+TiC含量对涂层显微组织及耐磨性能的影响。结果表明:通过等离子熔覆合成TiB_2和TiC陶瓷相,陶瓷相含量对涂层在不同载荷下的摩擦学性能和磨损机制有较大影响。在30N磨损载荷下,复合陶瓷通过阻碍裂纹扩展抑制剥层磨损的作用;在60N磨损载荷下,高硬度、高强度陶瓷可以有效降低磨粒磨损和黏着磨损的作用。另外,在高陶瓷含量的涂层磨痕表面发现有压实层结构分布,有效降低摩擦因数和磨损率。在30和60 N的磨损载荷下,TiB_2-TiC复合陶瓷通过不同的磨损机制提高涂层的磨损性能。     

时效状态对挤压铸造(Al2O3f+Cf)/ZL109混杂复合材料耐磨性能的影响

利用挤压铸造法制备了(Al2O3f Cf)/ZL109混杂复合材料,研究了时效状态对该混杂复合材料耐磨性能的影响.结果表明:(Al2O3f Cf)/ZL109混杂复合材料在峰时效阶段及过时效初期具有较佳的耐磨性能,而在该阶段以后,磨损表面大量脆性剥落坑的产生导致复合材料耐磨性降低.     

Characterization of Al-12Si alloy and its composites in dry sliding friction and wear at elevated temperature

1　INTRODUCTIONDiscontinuousreinforcementsreinforcedalu minumalloycomposites(DRACs)havesuperiorwearproperty ,especiallyhighseizureresistanceatelevatedtemperaturecomparedwithcommonaluminumal loys ,whichhavebeenreceivedconsiderableattentionin pasttwodecades[13] .TherearereportsaboutDRACsusedinpistonorblockin Ref.[4 ].Toim provethefrictionandwearpropertiesofaluminiumalloysfurther ,thehybridcompositesrepresentedthemergingoftwophilosophiesintribologicalalloyde sign—hard reinforcementsreinf…     

Dry sliding wear behavior of Al 2219/SiCp-Gr hybrid metal matrix composites

The dry sliding wear behavior of Al 2219 alloy and Al 2219/SiCp/Gr hybrid composites are investigated under similar conditions. The composites are fabricated using the liquid metallurgy technique. The dry sliding wear test is carried out for sliding speeds up to 6 m/s and for normal loads up to 60 N using a pin on disc apparatus. It is found that the addition of SiCp and graphite reinforcements increases the wear resistance of the composites. The wear rate decreases with the increase in SiCp reinforcement content. As speed increases, the wear rate decreases initially and then increases. The wear rate increases with the increase in load. Scanning electron microscopy micrographs of the worn surface are used to predict the nature of the wear mechanism. Abrasion is the principle wear mechanism for the composites at low sliding speeds and loads. At higher loads, the wear mechanism changes to delamination.     

Microstructures and wear properties of graphite and Al2O3 reinforced AZ91D-Cex composites

The magnesium matrix composites reinforced by graphite particles and Al2O3 short fibers were fabricated by squeeze-infiltration technique. The additions dispersed uniformly and no agglomeration and casting defect were observed. The microstructures and wear properties of the composites with different Ce contents of 0, 0.4%, 0.8% and 1.0%, respectively, were investigated. Especially, the effect of Ce on the properties was discussed. The results reveal that Ce enriches around the boundaries of graphite particles and forms Al3Ce phase with Al. The addition of Ce refines the microstructures of the composites. With the increase of Ce content, the grain size becomes smaller and the wear resistance of the composite is improved. At low load, the composites have similar worn surface. At high load, the composite with 1.0% Ce has the best wear resistance due to the existence of Al3Ce phase. The Al3Ce phase improves the thermal stability of the matrix so the graphite particles can keep intact, which can still work as lubricant. At low load, the wear mechanism is abrasive wear and oxidation wear. At high load, the wear mechanism changes to delamination wear for all the composites.     

石墨含量对石墨/TiC/镍基合金复合涂层微观组织与摩擦学性能的影响

为了降低TiC/镍基合金复合涂层的摩擦因数并增强其耐磨性能,运用等离子喷涂技术在45#钢表面制备石墨/TiC/镍基合金（GTN）复合涂层。研究石墨含量对GTN涂层组织和摩擦学性能的影响。结果表明,石墨的加入有效地降低了涂层的摩擦因数,提高了其耐磨性。6.56GTN涂层和12.71GTN涂层分别在低载荷与高载荷摩擦条件下呈现出优异的减摩耐磨性能。在低载荷条件下,GTN涂层的磨损机理主要表现为多次塑变磨损,伴有轻微的磨粒磨损,且随着石墨含量的增加逐渐转变为多次塑变、层脱和微切削磨损;在载荷增加后,脆性断裂、微观切削和粘着为其主要的磨损机理,且随着石墨含量的增加逐渐转变为微观切削和脆性剥落。     

Tribological behavior of self lubricating Cu/MoS2 composites fabricated by powder metallurgy

The effects of MoS₂ content on microstructure, density, hardness and wear resistance of pure copper were studied. Copper-based composites containing 0–10% (mass fraction) MoS₂ particles were fabricated by mechanical milling and hot pressing from pure copper and MoS₂ powders. Wear resistance was evaluated in dry sliding condition using a pin on disk configuration at a constant sliding speed of 0.2 m/s. Hardness measurements showed a critical MoS₂ content of 2.5% at which a hardness peak was attained. Regardless of the applied normal load, the lowest coefficient of friction and wear loss were attained for Cu/2.5MoS₂ composite. While coefficient of friction decreased when the applied normal load was raised from 1 to 4 N at any reinforcement content, the wear volume increased with increasing normal load. SEM micrographs from the worn surfaces and debris revealed that the wear mechanism was changed from mainly adhesion in pure copper to a combination of abrasion and delamination in Cu/MoS₂ composites.     

Effect of graphite particle size on wear property of graphite and Al_2O_3 reinforced AZ91D-0.8%Ce composites

The graphite particles and Al_2O_3 short fibers reinforced AZ91D-0.8%Ce composites were fabricated by squeeze-infiltration technique.The researches about the effects of different graphite particle sizes on the microstructure and wear property of the composites were performed under the condition of constant contents of graphite particles and Al_2O_3 short fibers.The results reveal that the grain size of the composites changes less when the graphite particle size descends.Moreover,Ce enriches around the gr...     

脉冲磁场下制备的TiB2增强ZL203复合材料的磨损行为

采用混合盐反应法制备了原位TiB2颗粒增强ZL203复合材料,在制备过程中施加脉冲磁场处理以提高复合材料的耐磨性能。研究了不同载荷条件下材料的干摩擦磨损行为。结果表明,原位TiB2颗粒的引入显著细化了复合材料的凝固组织,施加脉冲磁场处理后复合材料的组织得到了进一步细化;与基体合金相比,原位TiB2颗粒的引入使得复合材料的耐磨性显著提高。而施加脉冲磁场处理后复合材料的耐磨性得到进一步提升,发生严重粘着磨损的临界载荷由80N提升到100N。磨损表面分析表明,基体合金的磨损机制为严重粘着磨损和剥层磨损共同作用,未施加脉冲磁场处理的复合材料的磨损为以磨粒磨损为主和轻微的粘着磨损,施加脉冲磁场处理后的复合材料主要为磨粒磨损。