颗粒增强铝基梯度复合材料的摩擦磨损性能

摘要采用新型喷射沉积技术制备SiC体积分数呈连续分布(0～30%)的Al-Si基梯度复合材料,利用MG-2000型销-盘磨擦磨损试验机,研究不同滑动转速和载荷对该梯度复合材料摩擦磨损性能的影响.采用SEM和MHV-2000型维氏硬度计研究该梯度复合材料的显微组织、硬度及其耐磨性的梯度分布规律.结果表明随着滑动转速和载荷的增大,梯度材料的摩擦因数逐渐降低;材料的磨损率随载荷的增加而增大,随滑动转速的提高先增大后减小,在转速500 r/min时达到最大;对比研究沉积态与热压态材料的摩擦磨损行为,喷射沉积态由于孔隙等缺陷的存在,其磨损形式主要是磨粒磨损和剥层磨损;热压后,梯度材料的磨损形式以磨粒磨损和粘着磨损为主;随基体中SiC含量的逐渐增加,锭坯各部分硬度和耐磨性也随之提高.     

T6态Al-10Si-5Cu-0.75Mg合金干滑动摩擦磨损性能的研究

利用UMT-2 型摩擦磨损试验机研究了T6态Al-10Si-5Cu-0.75Mg 合金的干滑动摩擦磨损性能,采取SEM、XRD、EDS等方法分析了合金在不同转速和载荷下的摩擦磨损行为。结果表明：合金的磨损率随转速和载荷的增加而增大,但在800 r/min的高转速下仍具有良好的耐磨性,15N高载荷时的磨损率相对于5N低载荷时只增加了291%,属于轻微磨损;摩擦系数的平均值在0.35-0.40范围内变化,且随时间的变化不大,具有较高的稳定性;另外,磨损机制由低速轻载时的磨粒磨损、粘着磨损向高速重载时的剥层磨损、氧化磨损转变。     

T6态Al-20Si-5Cu合金干滑动摩擦磨损特性研究

以T6态Al-20Si-5Cu合金为研究对象,采用UMT-2型摩擦磨损试验机研究材料的摩擦磨损性能,并用SEM、EDS、奥林巴斯激光共焦扫描显微镜OLS4000分析材料的常温摩擦磨损行为。结果表明:Al-20Si-5Cu合金的磨损率随着附加载荷的增加而增大,但在高载荷下磨损率仍然很小,表现出了良好的耐磨性;摩擦系数平均值在0.38~0.42范围内变化,且在磨损过程中随时间的变化不大,表现出了较强的稳定性;同时,随着载荷的增大,材料的磨损机制发生改变,由低载荷的氧化磨损、磨粒磨损转变为疲劳磨损。     

A356/SiC_P与列车实用中的有机闸片的滑动摩擦磨损特性

以铝基复合材料作为列车制动盘材料的实用化为目的,选用A356/SiC 20%(体积分数,下同)复合材料和AISI D2工具钢为摩擦材料,以中速列车实用中的有机闸片为对偶材料,进行对比干摩擦磨损试验,并分析比较了磨损特性.结果表明:铝基复合材料在小于200 N(3.98 MPa)的低载荷下,只存在轻微的氧化磨损,耐磨性比实用中的铁合金材料更好;而超过该载荷时,开始发生磨削磨损,磨损量逐步超过铁合金材料,当载荷达到400 N(7.96 MPa)时,由于严重的磨削磨损,磨损量剧增.而铁合金材料则随载荷和滑动速度增加,磨损率缓慢增加;磨损过程中的复合材料的摩擦系数平均值与载荷、滑动速度无关,始终保持0.3～0.4,同时随磨损距离的波动也非常小,而工具钢的摩擦系数平均值则对试验参数的敏感度相对大些,且摩擦系数平均值也比复合材料略小,即摩擦系数方面复合材料具有更好的特性.     

Effects of Cu Content on Thermal Stability and Wear Behavior of Al-12.5Si-1.0Mg Alloy

This study investigates how Cu content affects thermal stability and wear behavior of Al-12.5Si-1.0Mg alloy, by adding 2.55 and 4.53 wt.% Cu. The low-Cu and high-Cu alloys were isothermally heat-treated at 300 °C for 100 h. The results indicated that the amount of eutectic Al₂Cu and Al₅Cu₂Mg₈Si₆ particles in the high-Cu alloy was more than that in the low-Cu alloy. These hard particles retained in the Al matrices during isothermal heat treatment, maintaining a relatively stable hardness. Therefore, the hardness of the high-Cu alloy was superior to that of the low-Cu alloy in as-cast condition and after isothermal heat treatment. For wear behavior, both isothermal heat-treated alloys showed the same wear rate with 10 N normal load. The wear rate of Al-12.5Si-1.0Mg alloy was independent on the copper content under 10 N load, but the wear rate at a load of 40 N decreased with increasing Cu content in Al-12.5Si-1.0Mg alloy.     

原位合成Al2O3增强铝基复合材料的摩擦磨损性能

通过采用粉末冶金和原位合成技术相结合的近净成形技术制备Al-5％Si-Al2O3复合材料,并运用M一2000摩擦磨损试验机对该复合材料的摩擦磨损性能进行研究。通过单一变量比较法分析载荷和滑动速度对Al-5％Si-Al2O3复合材料摩擦磨损性能的影响,同时对长时间连续磨损下该材料的摩擦性能进行研究。通过扫描电子显微镜对Al-5％Si-Al2O3复合材料的磨损表面进行观察,并分析其磨损机制。结果表明,随着载荷的增大,试样的磨损量和摩擦因数均增加;随着滑动速度的增大,试样表面的升温使得产生氧化层的速率增加,试样的磨损量和摩擦因数均减少。在长时间的连续磨损过程中,由于初始时发生粘着磨损,试样的摩擦因数随着滑动距离的增大而增大。然后,试样表面氧化层的形成和破坏趋于动态平衡,试样表面相对稳定,其摩擦因数也随之趋于平稳。铝基复合材料的磨损机制主要为磨粒磨损、粘着磨损和氧化磨损。     

氮化钛 / 氧化钛复相陶瓷涂层的干滑动摩擦磨损性能

目的研究等离子喷涂Ti N/Ti O复相陶瓷涂层的微观组织结构、显微硬度及干滑动摩擦磨损行为和机理。方法采用等离子喷涂技术,在45#钢表面制备Ti N/Ti O复相陶瓷涂层。分析涂层的相组成,测试涂层的硬度。通过磨损试验研究Ti N/Ti O复相陶瓷涂层的磨损行为,并观察涂层的磨损形貌,测试磨损表面的成分组成,探讨Ti N/Ti O复相陶瓷涂层的磨损机理。结果 Ti N/Ti O复相陶瓷涂层均匀致密,平均厚度为350μm,具有明显的层状结构,孔隙率为4.3%,显微硬度为1444HV0.1。在载荷30~50 N、转速370~1102 r/min的范围内,Ti N/Ti O复相涂层与GCr15对磨的摩擦系数为0.0963~0.2778,磨损量为1.32~6.8 mg。随着载荷的增加,摩擦系数下降;随着载荷和转速的增加,磨损量增加。结论等离子喷涂制备的Ti N/Ti O复相涂层组织致密,显微硬度高,在低速低载荷时表现出较好的耐磨性,但随着载荷和转速的增加,耐磨性降低。涂层的磨损机制主要为磨粒磨损和粘着磨损。     

双连续复合材料SiC/Fe-40Cr与SiC/Al2618合金干摩擦磨损行为的实验研究与数值分析(英文)

利用环环式摩擦磨损试验机研究双连续复合材料SiC/Fe40Cr与SiC/2618Al合金在滑动速度30~105m/s,载荷1.0~2.5MPa条件下的干摩擦磨损性能。实验结果表明,在较高的载荷和滑动速度下,SiCn/2618Al复合材料的磨损机制是两体磨料磨损和氧化磨损。作为增强相的连续网络结构的SiC陶瓷可避免通常发生在传统的粒子增强复合材料上的第三体磨损现象。机械混合层(MML)极大地控制了复合材料的磨损速率和摩擦系数。在进行较高的滑动速度测试时,由于机械混合层的间歇的生形和消除,复合材料表现出较高的摩擦系数和波动。为了便于有限元模型(FEM)计算,用一个连续结构单元来代表三维碳化硅结构增强铝基复合材料的微观结构。利用有限元模型(FEM)预测的复合材料磨损和应力应变数据与实验数据一致     

SiC_P尺寸对铜基复合材料抗氧化性及磨损性的影响

采用粉末冶金法制备了SiC粒径分别为10、20和40μm的SiCP./Cu复合材料,对复合材料的抗氧化性和耐磨损性进行了研究,并对磨损形貌进行了观察.结果表明,在氧化温度为400～700℃时,SiCp/Cu复合材料的抗氧化性优于纯铜,粒径为20μm的SiCp,/Cu复合材料的抗氧化性最优.复合材料的磨损性能也随SiCp粒径的变化发生明显改变,在载荷≤100N时,SiCp粒径增大有助于提高复合材料的耐磨性,其磨损机制主要是磨粒磨损;随着载荷的增加,大粒径SiCp易于破损,复合材料磨损率剧增,其磨损机制是磨粒磨损及剥层磨损的复合作用.     

Al-10％Fe合金梯度材料的组织与性能

采用离心铸造技术成功地制得了过共晶Ａｌ－１０％Ｆｅ梯度材料,离心机转速每分钟１４００转,金属模具预热温４５０℃,浇注温度１０００℃,采用金相及扫描电子显微镜、ＨＶ－５小负荷维氏硬度计及销盘式ＭＬ－１００型磨粒磨损试验研究了梯度材料组织、硬度及耐磨性的分布规律,结果表明由于初晶Ａｌ３Ｆｅ密度比Ａｌ液密度高,在离心力场初中晶Ａｌ３Ｆｅ向试样外侧移动。Ａｌ－１０％Ｆｅ合金梯度材料的组织分布为最外层初晶Ａ     

High-speed friction and wear behaviors of bulk Ti3SiC2

High-speed friction and wear behaviors of bulk Ti3 SiC2 sliding drily against low carbon steel were investigated. Tests were carried out using a block-on-disk type tester with normal pressures ranging from 0.1 to 0.8 MPa and several sliding speeds from 20 to 60 m/s. The results show that, in the case of sliding speeds of 20 40 m/s, the friction coefficient exhibits a decreasing tendency with increasing the normal pressure after an increment in the smaller pressure range, and the worn quantity of Ti3SiC2 exhibits a nearly linear increase with increasing the normal pressure. However, when the sliding speed is up to 60 m/s, the friction coefficient exhibits a monotonous increase and the worn quantity exhibits a quadric increase with increasing the normal pressure. These speed-dependent and pressure-dependent behaviors are attributed to the antifriction effects of a frictionally generated oxide film covering the friction surface of Ti3 SiC2, and a balance between the generating rate and the removing (wearing) rate of the film.     

SiC_p/ZA27复合材料的摩擦磨损性能

探讨了不同含量、不同大小ＳｉＣｐ增强ＺＡ２７复合材料的摩擦磨损特性,并借助ＳＥＭ,ＥＤＡＸ对磨面及其剖面、磨屑进行了分析。结果表明：随着ＳｉＣｐ含量的增加,复合材料的磨损量急剧下降,摩擦系数也呈下降趋势,磨损机制将从粘着和剧烈切屑磨损转向微切削磨损;随着ＳｉＣｐ尺寸的增大,磨损量先急剧减小后趋于稳定,摩擦系数先减小后又升高,磨损机制将从粘着和剧烈切削转向微切削和因ＳｉＣｐ脱粘造成的磨料磨损;经ＸＲＤ分析复合材料的磨屑由Ｚｎ和Ａｌ的固溶体相及ＳｉＣｐ和对磨块４５＃钢的Ｆｅ相组成。     

镧对Cu/Ti3SiC2/C/MWCNTs/Graphene/La纳米复合材料摩擦学性能的影响

本研究采用真空热压及热等静压方法制备Cu/Ti3SiC2/C/MWCNTs/Graphene/La纳米复合材料,采用摩擦磨损试验机研究对磨材料为GCr15时,镧含量对Cu/Ti3SiC2/C/MWCNTs/Graphene/La纳米复合材料的摩擦学性能的影响。研究了镧含量、正应力及旋转速度对纳米复合材料摩擦学行为的影响并揭示其相互作用机理,采用正交试验分析、方差分析及极差分析法来分析镧含量、正应力及旋转速度的相互作用。采用扫描电镜和能谱仪观察并分析磨损表面及磨削的形态及成分组分。研究结果表明镧对纳米复合材料的摩擦磨损性能起到首要作用,当镧的质量分数为0.05%时,复合材料的磨损机理为磨粒磨损、剥层磨损和氧化磨损,而当镧的质量分数为0.1%和0.3%时,复合材料的磨损机理为粘着磨损和氧化磨损。     

Microstructure and mechanical properties of rapidly solidified Al-20Si-xFe-3Cu-lMg (x=0 and 5 wt.%) Extradates

The effects of Fe addition and initial powder size distribution on mechanical properties of Al-20Si-3Cu-lMg alloy, prepared by gas atomization and followed by hot consolidation, were studied by using optical microscopy, transmission electron microscopy, X-ray diffractometry, tensile and wear test. The Al-20Si-xFe-3Cu-lMg (x=0, 5) alloys showed homogeneous and refined microstructure. Addition of Cu and Mg to Al-20Si alloy showed increased tensile property due to precipitation hardening. Addition of Fe to Al-20Si-3Cu-lMg increased tensile strength further due to the formation of spherical Al-Si-Fe compound during hot consolidation and phase transformed from the metastable phase. Alloy bars prepared from powder with wide-size distribution showed low tensile strength and wear resistance.     

Wear characteristics of Al−Si−Mg−(Cu)/Al2O3 composites fabricated by thermit reaction

Al₂O₃ particles could be formed by a thermit reaction in an Al-12Si-4Mg-1.5Cu/Al₂O₃ composite due to thein-situ reaction between Al-12Si-4Mg-(1.5Cu) molten metal and SiO₂ particles in preform, which took place at 1173 K for 24 hours, resulting in the decomposition of SiO₂ particles and the formation of Al₂O₃ particles simultaneously. The mechanically mixed layers (MMLs) consisting of α-Fe and Fe oxides existed on the subsurface layers beneath the worn surface in composites or mother alloys, which improved the wear resistance. The characteristics of wear resistance and hardening of an Al-12Si-4Mg-1.5Cu/Al₂O₃ composite are superior to those of the Al-12Si-4Mg/Al₂O₃ composite and Al-12Si-4Mg-1.5Cu alloy.     

含高体积分数SiC_p的Al复合材料微观组织及弯曲性能

利用无压浸渗法制备高体积分数SiC的SiC_p/Al复合材料.采用XRD和SEM对复合材料的相组成、微观组织及断口形貌进行分析,研究颗粒粒径分布和基体合金成分对复合材料抗弯性能的影响.结果表明:以Al-10Si-8Mg(质量分数,%)合金为基体制备的复合材料组织均匀,致密度好,无明显气孔缺陷;界面反应产物为Mg2Si、MgAl_2O_4和Fe,其弯曲强度高于以Al-10Si合金为基体制备的复合材料的弯曲强度;SiC_p/Al复合材料的弯曲强度随着SiC颗粒粒径的增大而减小;复合材料整体上表现出脆性断裂的特征.     

Sliding behavior and wear mechanism of iron and cobalt-based high-temperature alloys against WC and SiC balls

The sliding behaviors of two typical high-temperature alloys of GH2132 and GH605 against WC and SiC balls were investigated at environments from room temperature to 800 °C with a sliding speed of 50 to 125 m/min under a load of 10 to 20 N. The wear performances of high-temperature alloys, WC and SiC balls were rated and their mechanisms were discussed. The four sliding pairs exhibited the markedly different sliding behaviours, in which the GH2132/WC sliding pair had the maximum friction coefficient with 125 m/min under 10 N at room temperature. The variation trends of ball wear rates with the ambient temperature were at odds with those of friction coefficient. The higher friction coefficient did not always lead balls to suffer from the higher wear rate. The maximum worn depth approximated to 250 μm for the GH2132/WC sliding pair with higher friction coefficient. The GH605/WC sliding pair exhibited the lower friction coefficient and lower worn depth of plate. Whether at room temperature or high temperature, the GH605/SiC sliding pair significantly exhibited good wear resistance with a minor damage of ball and plate despite of its higher friction coefficient.     

应用模压铸造法制造的Al2O3f/SiCp混杂增强铝基复合材料的摩擦磨损行为（英文）

研究了通过模压铸造方法制造的氧化铝纤维与碳化硅颗粒混合增强铝基复合材料的干摩擦磨损性能。分别在室温、110℃,以及150℃条件下,进行了恒速0.36m/s(570r/min)的销盘式摩擦磨损实验。采用扫描电子显微镜观察干磨损表面特征,采用Arrhenius作图法研究相对磨损率,以便于进一步研究磨损机制。此外,讨论了纤维的方向性和纤维与颗粒的混合比作用。     

Friction and wear properties of steel backed Al-10Sn-4Si-1Cu metallic strips prepared via spray atomization-deposition-rolling route

In various load bearing structural applications related to automotive industries, steel backed aluminum alloy strips are considered. For such applications, it is desired to design appropriate alloy composition for metallic strip so that good tribological properties can be achieved. In our ongoing efforts to accomplish this aim, we have recently fabricated a steel backed Al-10Sn-4Si-1Cu bearing strip, which is prepared by spray depositing the molten bearing alloy on a steel substrate, followed by warm rolling of the resulting laminated strip to different thickness reductions up to 80%. The tribological performance of the steel backed Al-10Sn-4Si-1Cu strips is evaluated against the bearing steel. While the recorded steady state coefficient of friction (COF) does not show any noticeable difference (varying in the range of 0.6-0.7) with respect to difference in warm rolling conditions, the fretting wear rate (10-26 × 10^− 5 mm³ N^− 1m^− 1) of the steel backed and warm rolled strips exhibits a systematic decrease in wear rate with increase in amount of warm rolling. SEM-EDS analyses reveal the oxidative wear and the extensive cracking of alumina rich tribolayer as the dominant material removal mechanisms. The tribological properties of the spray deposited and 80% rolled steel backed Al-10Sn-4Si-1Cu bearing strip is compared with those of a commercially available Al-Sn based sleeve bearing under identical fretting conditions.     

Friction Wear Property of Brake Materials by Copper-based Powder Metallurgy With Various Brake Speeds

The experiment is conducted on MM-1000 friction test machine, which tests friction wear property of copper-based brake materials by powder metallurgy at different brake speeds. It shows that the coefficient of friction and wear volume are greatly influenced by brake speed. When the brake speed is 4000 r/min, which is a bit higher, the material still has a higher coefficient of friction with 0.47. When the brake speed is over 4000r/min. the coefftcient of friction decreased rapidly. When the brake speed is 300Of/rain, the material‘s wear is in its minimum. That is to say no matter how higher or lower the brake speed is the wear volume is bigger relatively. With the brake speed of the lower one it mainly refers to fatigue wear; while of higher one it mainly refers to ahradant and oxidation wear.