不同类型颗粒混合增强铁基复合材料的磨损性能EI北大核心CSCD

采用电流直加热动态热压烧结工艺制备陶瓷颗粒增强铁基复合材料,研究高体积分数(25%,30%,35%)下,单一类型颗粒(SiC,TiC,TiN)及混合类型颗粒(TiC+TiN,SiC+TiN,SiC+TiC)作为增强相对铁基复合材料磨损性能的影响。结果表明:单一类型粒子强化时,TiNP/Fe复合材料的耐磨性最好,TiCP/Fe次之,SiCp/Fe最差。混合粒子作为增强体时,(TiC+TiN)P/Fe复合材料磨损性能显著优于其对应的单一颗粒增强材料;其中粒子含量为30%时,(TiC+TiN)P/Fe复合材料磨损性能提高最大,其磨损量比TiCP/Fe降低了51.9%,比TiNp/Fe复合材料降低了44.1%,体现出可贵的混合增强价值。(SiC+TiC)_P/Fe和(SiC+TiN)P/Fe复合材料的磨损性能分别处于对应的两个单一颗粒增强材料之间。磨损表面观察表明,耐磨性好的(TiC+TiN)P/Fe复合材料的磨损机理为磨粒磨损,而(SiC+TiC)_P/Fe和(SiC+TiN)P/Fe复合材料除磨粒磨损外还存在明显的疲劳磨损现象。     

TiCp/Ti6Al4V复合材料的耐磨性及磨损机制

为表征颗粒增强钛基复合材料在恶劣的磨粒磨损条件下的磨损行为,对熔铸法制备的TiCP/Ti6Al4V进行了磨粒磨损条件下的耐磨性试验,并利用SEM、EDX等技术分析了复合材料的磨损过程及磨损机制.研究表明:TiCP/Ti6Al4V复合材料的抗磨粒磨损性能,总体上随TiC颗粒体积分数的增加而提高,载荷越大、磨损时间越长,复合材料越容易表现出优异的耐磨性能;TiC的形态影响着耐磨性的提高,细小颗粒状或羽毛状TiC单位体积增加对耐磨性的贡献,比枝晶状TiC单位体积增加对耐磨性的贡献大约3.5倍;复合材料在磨损初始阶段,其磨损机制以形成犁削和磨沟为主,形成一次磨屑,随着增强相含量的提高,一次磨屑逐步减少,磨损以犁沟和剥层磨损为主,需要磨粒的反复作用才能形成磨屑,因此,耐磨性得到提高.     

不同类型陶瓷颗粒对铁基复合材料力学性能的影响

采用电流直加热动态热压制备,研究了不同类型陶瓷颗粒(SiC、Cr3C2、TiC和Ti(C,N))增强铁基复合材料的力学性能,并应用Eshelby等效夹杂方法来考察不同类型增强粒子载荷传递的贡献,用以解释实验现象和揭示强化机理。结果表明,SiC颗粒对改善复合材料抗拉强度的作用最好,Cr3C2粒子次之;TiC/Fe和Ti(C,N)/Fe复合材料的强化机理以增加粒子承担载荷的方式为主,而SiC/Fe和Cr3C2/Fe复合材料的增强机理除载荷传递外,还存在增强铁基体本身强度的作用。     

SiCp/Al复合材料的磨损特性分析

本文研究了SiC颗粒增强铝基(ZL102)复合材料的磨损特性。结果表明,SiC颗粒的加入可提高材料的耐磨性,复合材料与基体合金相比,磨损速率相当低,而且其抗粘着磨损能力更强,磨损性能与增强相数量、分布及界面结合有关。      

TIC/7075铝基复合材料的磨损实验研究

采用原位反应喷射沉积法制备TiC/7075铝基复合材料,并在销一盘式磨损机损上进行摩擦磨损实验研究.通过TEM观察原位TiC颗粒的分布与形貌,并利用SEM观察沉积态组织磨损表面形貌.结果表明:复合材料的耐磨性和TiC颗粒含量及载荷有关,在低载荷(8.9N)状态下,材料的耐磨性随TiC颗粒含量的增加而增强,在高载荷(26...     

激光熔覆原位自生TiC颗粒增强镍基复合涂层的组织与耐磨性

采用预置粉末法在45钢表面进行激光熔覆镍基Ni60A+x%(SiC+Ti)(质量分数,下同)复合粉末涂层的实验研究。使用往复式磨损试验机对不同涂层材料的熔覆层进行干摩擦磨损实验,利用金相显微镜、扫描电镜(SEM)观察和分析熔覆层的显微组织与磨损形貌。结果表明:复合粉末通过原位反应生成弥散分布的TiC颗粒增强复合涂层,随着(SiC+Ti)含量的增加,颗粒状TiC的尺寸和数目逐渐增加;复合粉(SiC+Ti)含量达到60%时,微观组织有气孔和夹杂缺陷;复合粉(SiC+Ti)含量为48%时,熔覆层耐磨性最佳;复合涂层的磨损主要为磨粒磨损,机理为微观切削和挤压剥落。     

SiC含量对环氧/SiC复合材料冲蚀磨损性能的影响

为了改善工厂、矿山中大型机件的耐冲蚀磨损性,利用SiC颗粒与环氧树脂制备了能够便捷涂覆和快速固化具有优异耐冲蚀磨损性能的环氧/SiC复合材料,着重考察了SiC含量对环氧/SiC复合材料冲蚀磨损性能的影响。用自制的冲蚀磨损试验机对复合材料进行了冲蚀磨损实验,采用SEM等手段对复合材料的冲蚀磨损形貌进行观察分析。结果表明:在复合材料中提高SiC含量可以提高其耐冲蚀磨损性能,当SiC质量分数为复合材料的66.66%时,SiC颗粒与树脂之间"阴影效应"和"粘接效应"相互配合达到最佳,复合材料的冲蚀磨损性能最好;当SiC含量最佳时,复合材料的耐冲蚀磨损性能要好于相同角度下白口铸铁。     

纳米陶瓷颗粒填充PTFE基复合材料的干摩擦磨损性能

利用MM-200型环-块摩擦磨损试验机研究了纳米陶瓷颗粒SiC、Si3N4、AlN和TiN对聚四氟乙烯(PTFE)复合材料在干摩擦条件下与45#钢对磨时的摩擦磨损性能的影响,借助于扫描电子显微镜观察分析了试样磨损表面形貌,并探讨了磨损机理。结果表明:添加纳米TiN减少了PTFE的摩擦系数,而添加纳米SiC、Si3N4增大了PTFE的摩擦系数。与纯PTFE相比,PTFE复合材料的耐磨性能显著提高,其中以纳米AlN的减磨效果最好,纳米Si3N4的减磨效果最差。纯PTFE的磨损机制主要表现为粘着磨损和疲劳磨损,而纳米粒子填充PTFE基复合材料的磨损机制主要表现为不同程度的粘着磨损、犁沟效应和塑性变形特征。     

纳米SiC与石墨填充PTFE复合材料的摩擦磨损性能

考察了不同含量的纳米SiC对石墨/聚四氟乙烯复合材料摩擦磨损性能的影响,采用扫描电子显微镜分析了磨损表面,并探讨了其磨损机理。结果表明:纳米SiC与石墨能够很好地协同增强聚四氟乙烯,纳米SiC的加入大大提高了复合材料的承载能力,石墨的加入减少了纳米SiC与对偶面的摩擦系数,从而降低了纳米SiC的脱落趋势,提高了复合材料的耐磨性。当纳米SiC含量为5%时,5%石墨/PTFE复合材料表现出最佳的耐磨性,具有一定的应用价值。     

粉末冶金法制备CNT和SiC混杂增强铝基复合材料的摩擦磨损性能EI北大核心CSCD

以7055Al为基体,通过粉末冶金法分别制备碳化硅(SiC)颗粒、碳纳米管(CNT)以及SiC和CNT混杂增强7055Al复合材料,并对三种复合材料的干滑动摩擦磨损行为进行研究。结果表明:随着载荷提高,复合材料磨损失重增加,摩擦因数略有降低。在0.5 MPa与1.0 MPa载荷条件下,SiC-CNT/7055Al复合材料磨损失重低于单一SiC/7055Al和单一CNT/7055Al复合材料。2.0 MPa时,SiC-CNT/7055Al复合材料磨损失重急剧增加。随着载荷提高,CNT/7055Al复合材料耐磨性逐渐增加,在中、高载荷下,材料具有更为优异的耐磨性。SiC/7055Al复合材料磨损量则随着载荷提高,磨损失重逐渐增加,当载荷为2.0 MPa时,材料磨损量增加幅度较小。     

Abrasive wear of FeCr (M7C3–M23C6) reinforced iron based metal matrix composites

Abstract

The effects of volume fraction, particle size, and sintered porosity of FeCr (M₇C₃–M₂₃C₆) particulates on the abrasive wear resistance of powder metallurgy (PM) Fe alloy metal matrix composites have been studied under different abrasive conditions. It was seen that the abrasive wear rate of the composites increased with an increase in the FeCr volume fraction in tests performed with 80 grade SiC abrasive paper, but it decreased for tests conducted with 220 grade SiC abrasive paper. Furthermore, the wear rates decreased with an increase in FeCr size for composites containing the same amount of FeCr. Hence it is deduced that Fe alloy composites reinforced with larger size FeCr particles are more effective against abrasive wear than those reinforced with smaller ones. At the same time the results show that the beneficial effects of hard FeCr particulates on wear resistance far outweighed the detrimental effects of sintered porosity in the PM metal matrix composites. In addition, the fabrication of composites containing soft particles such as graphite or copper favours a reduction in the coefficient of friction, and increases the matrix hardness of the composite. For this reason graphite and copper were used in the matrix in different amounts to test their effect on the wear resistance. Increase in graphite and copper volume fraction allowed the formation of additional phases, which had high hardness and wear resistance. It was also found that the wear rate of the composites decreased considerably with graphite and copper addition.     

Wear characteristics of TiC reinforced cast iron composites Part 2 – Abrasive wear

Abstract

The presence of carbide particles in metal matrix composites improves abrasive wear resistance properties. Abrasive wear characteristics of TiC reinforced cast iron composites have been investigated. The TiC particle size and distribution influence the wear properties of the composites. TiC reinforced cast iron composites possess better wear resistance properties than those of chromium cast irons with and without nitrogen.     

Fabrication of in situ TiC locally reinforced manganese steel matrix composite via combustion synthesis during casting

In situ TiC particulates locally reinforced manganese (Mn) steel matrix composite was successfully fabricated via combustion synthesis of (Fe,Ti)–C system during casting. XRD results reveal that the phases of the composites consist of TiC, α-Fe and austenite. Microstructure of the locally reinforced manganese (Mn) steel matrix composite consists of three separate regions, i.e. a TiC particulate-reinforced region, a transition region, a steel matrix region. TiC particles in the reinforced region, having fine size of 2 μm, are distributed uniformly. The hardness and wear resistance of the TiC particulates locally reinforced composites are much higher than those of quenched Mn13 steel. Furthermore, the microstructure formation mechanism of the composite was discussed.     

Abrasive wear of Al2O3-reinforced aluminium-based MMCs

The effects of volume fraction, Al₂O₃ particle size and effects of porosity in the composites on the abrasive wear resistance of compo-casting Al alloy MMCs have been studied for different abrasive conditions. It was seen that porosity in the composites is proportional to particle content. In addition, process variables like the stirring speed, and the position and diameter of the stirrer affect of the porosity content in a way similar to that observed for particle content. In addition, the abrasive wear rates of composites decreased more rapidly with increase in Al₂O₃ volume fraction in tests performed over 80 grade SiC abrasive paper than in tests conducted over 220 grade SiC abrasive paper. Furthermore, the wear rates decreased with increase in Al₂O₃ size for the composites containing the same amount of Al₂O₃. Hence, it is deduced that aluminium alloy composites reinforced with larger Al₂O₃ particles are more effective against abrasive wear than those reinforced with smaller Al₂O₃ particles. At the same time the results show that the beneficial effects of hard Al₂O₃ particles on wear resistance far surpassed that of the sintered porosity in the compocasting metal-matrix composites (MMCs). Nevertheless, the fabrication of composites containing soft particles such as graphite favors a reduction in the friction coefficient. For this reason graphite and copper were used in the matrix in different amounts to detect their effect on wear resistance. Finally, it was seen that wear rate of the composites decreased considerably with graphite additions.     

微波烧结原位合成TiC增强钛复合材料的性能

以纳米管(MWCNTs)和纯钛为原料,用微波烧结法原位合成TiC增强钛基复合材料,研究了这种材料的组织和性能并探讨了TiC增强相的生成机理。结果表明,微波烧结时MWCNTs与Ti原位生成TiC增强相。MWCNTs的添加量(质量分数,下同)低于1%时TiC呈现颗粒状且分布均匀,Ti基体致密;MWCNTs的添加量高于1.5%时TiC呈树枝晶形貌,Ti基体的组织粗化使复合材料出现较多的孔洞。MWCNTs的添加使材料由粘着磨损为主转变为磨粒磨损为主。随着MWCNTs添加量的提高,复合材料的显微硬度先提高后降低。MWCNTs添加量为1%的复合材料显微硬度最高(约为527HV)、耐磨性能最好(摩擦系数约为0.35)。与纯钛相比,TiC增强钛基复合材料的显微硬度提高了1.2倍,摩擦系数降低了0.4。     

碳化硼颗粒增强Cu基复合材料的研究

研究了用表面涂覆含钛金属涂层的碳化硼颗粒增强Cu基复合材料[B4Cp/(TiB2 TiN)/Cu],并与未经涂覆的B4C颗粒增强Cu基复合材料（B4Cp/Cu)进行了对比。实验结果表明,前者的致密度和电导率比后者好。磨损实验结果表明,使用有涂层颗粒的复合材料的耐磨性比无涂层颗粒的好。通过对复合材料界面和磨损表面的电镜观察表明,B4C颗粒经过涂覆处理后,改善了复合材料的界面粘结性能,颗粒与基体间有良好的浸润性。     

SiC 和Gr 颗粒混杂增强Al 基复合材料的摩擦磨损特性的研究

比较了SiC 和Gr 颗粒混杂增强Al 基复合材料的干摩擦磨损行为, 并与单一SiC_P 和单一G_rP 增强Al 基复合材料的相应行为进行了比较。结果表明, 在低载荷(< 30 N ) 时, SiC_P 和G_rP 能协调作用, 使混杂复合材料的摩擦系数和磨损率均比单一SiC_P 和G_rP 增强复合材料低。在较高载荷(30～ 120 N ) 时, 混杂复合材料磨损以剥层磨损机制为主, 摩擦系数比单一SiC_P 增强复合材料低, 磨损率比单一G_rP 增强复合材料低得多, 比单一SiC_P 增强复合材料高。混杂复合材料对偶件的磨损比单一SiC_P 增强复合材料低得多。      

构型陶瓷/钢铁耐磨复合材料研究进展

近年来,陶瓷颗粒非均匀分布增强钢铁基复合材料(构型复合材料)由于具有优异的耐磨性,成为国内外高性能耐磨材料研究和应用的热点.对构型复合材料耐磨性的研究进行了综述,认为在无冲击磨料磨损工况下,构型复合材料的耐磨性显著高于常规陶瓷颗粒均匀分布增强复合材料,其耐磨性顺序按照基体排列为:高铬铸铁基>合金钢基>高锰钢基复合材料;陶瓷/钢铁界面结合强,则复合材料耐磨性高;按照陶瓷颗粒排序是:WC>(TiC,ZTA)>Al2O3增强复合材料;ZTA中ZrO2含量高,则耐磨性好.在高冲击磨料磨损工况下,构型复合材料耐磨性远不如无冲击工况下的耐磨性,有的甚至比基体差;合金钢基复合材料耐磨性比高锰钢基稍高.综述了不同工况下构型复合材料的磨损机理,并提出了构型陶瓷/钢铁复合材料的研究方向.     

Microstructure and abrasive wear behaviour of B<Subscript>4</Subscript>C particle reinforced 2014 Al matrix composites

In this study, the microstructure and abrasive wear properties of varying volume fraction of particles up to 12% B₄C particle reinforced 2014 aluminium alloy metal matrix composites produced by stircasting method was investigated. The density, porosity and hardness of composites were also examined. Wear behaviour of B₄C particle reinforced aluminium alloy composites was investigated by a block-on-disc abrasion test apparatus where the samples slid against the abrasive suspension mixture (contained 10 vol.% SiC particles and 90 vol.% oil) at room conditions. Wear tests performed under 92 N against the abrasive suspension mixture with a novel three body abrasive. For wear behaviour, the volume loss and specific rate of the samples have been measured and the effects of sliding time and the content of B₄C particles on the abrasive wear properties of the composites have been evaluated. The dominant wear mechanisms were identified using SEM. Microscopic observation of the microstructures revealed that dispersion of B₄C particles was generally uniform while increasing volume fraction led to agglomeration of the particles and porosity. The density of the composite decreased with increasing reinforcement volume fraction but the porosity and hardness increased with increasing particle content. Moreover, the specific wear rate of composite decreased with increasing particle volume fraction. The wear resistance of the composite was found to be considerably higher than that of the matrix alloy and increased with increasing particle content.