挤压态AZ61镁合金磨损性能研究

主要研究了挤压态AZ61镁合金在不同载荷和滑动摩擦速度条件下的磨损性能。采用SEM对磨损面进行显微组织观察与分析,讨论了不同载荷下材料的主要磨损形式。结果表明,磨损质量损失随着滑动摩擦速度和载荷的增加而增加。挤压态AZ61镁合金的磨损机制主要分为轻微磨损和严重磨损。轻微磨损主要是擦伤磨损、氧化磨损与剥层磨损,在磨损面上形成的擦痕与裂纹,其磨损程度较轻,磨损面积小;当载荷增加到100N和120N时,塑性变形和熔化在磨损面形成的磨痕较深且磨损面积大,表现为严重磨损。     

Effect of Bagasse ash reinforcement on the wear behaviour of Al-Cu-Mg/Bagasse ash particulate composites

The effect of Bagasse ash (BAp) particle reinforcement on the wear behavior of Al-Cu-Mg alloy has been studied.  Bagasse ash particles were varied from 0 wt pct-10 wt pct with interval of 2 wt pct. Unlubricated pin-on disc tests were conducted to examine the wear behaviour of the aluminium alloy/Bagasse ash particulate composites. The tests were conducted at varying loads, from 5 to 20 N and sliding speeds of 1.26 m/s, 2.51 m/s , 3.77 m/s and 5.02 m/s for a constant sliding distance of 5000 m. The results showed that the wear rates of the Al-Cu-Mg/BAp composites are lower than that of the matrix alloy and further decrease with increasing Bagasse ash content. Wear rate increases as the sliding speed and applied load increase. The microstructure of the worn surface revealed that a large amount of plastic deformation appeared on the surface of the unreinforced alloy. While Bagasse ash reinforced Al-Cu-Mg alloy showed worn out surface that is not smooth, and grooves, scratches and parallel lines were observed. A combination of adhesion and delamination wear was in operation. These results show that improve wear properties is achievable for the aluminium alloy by the addition of Bagasse ash particles as reinforcement material.     

Wear behaviour of hot rolled AZ31B magnesium alloy as candidate for biodegradable implant material

Surface integrity and tribological behaviour of implant materials have a critical impact on their performance in the body. To understand wear behaviour well, the present article focuses on the sliding wear behavior of hot rolled AZ31B magnesium alloy which is a good candidate for biodegradable implant material. Dry-sliding conditions which include pin-on disc method with heat-treated high-carbon steel disc as counterface were used. Wear rates at a fixed sliding distance of 5000 m were measured at sliding velocities of 0.25, 0.5, 1 and 2 m/s, and loads of 10, 20, 40 and 80 N. Microstructure of worn surfaces of pins was characterized using SEM/EDS. Wear mechanism maps of the investigated materials were composed to understand comprehensively. According to test results, abrasive wear occurred at load of 20 N and sliding speed of 0.25 m/s while melting wear was predominant at load of 80 N and sliding speed of 2 m/s. Results show that ultra-severe plastic deformation is the main wear mechanism at the highest applied load and sliding velocity speed for the investigated alloy. Consequently, hot rolled AZ31B magnesium alloy exhibited a good wear resistance due to fine microstructure and high hardness.     

增强颗粒对镁基复合材料磨损性能的影响(英文)

研究增强颗粒Mg2Si对镁基复合材料摩擦磨损性能的影响,讨论Si加入量、载荷和滑动速度对Mg2Si/AM60镁基复合材料磨损性能的影响。结果表明,向镁合金中加入合金元素Si,可原位生成增强颗粒Mg2Si,增强颗粒Mg2Si可明显提高AM60镁合金的磨损性能。随着载荷和滑动速度的增加,AM60镁合金和Mg2Si/AM60镁基复合材料的磨损量都增大。AM60镁合金的磨损机制为粘着磨损。随着载荷的增大,Mg2Si/AM60镁基复合材料的磨损由磨粒磨损向粘着磨损转变。     

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。     

Effect of extrusion ratio on the wear behaviour of Al-Si and Al-Mg alloys

In this study, the wear behaviour of hot extruded Al-Si and Al-Mg alloys was investigated under dry conditions. Die cast Al-Mg alloy containing 1.7% Mg and Al-Si alloy containing 3.3% Si were extruded at 1.6 and 2 ratios. Mechanical and microstructural characterisations of the extruded alloys were carried out through optical microscopy, hardness measurements and tensile testing. Wear tests were carried out on a pin-on-disc type wear device and the worn surfaces were examined under a scanning electron microscope (SEM). The wear test results revealed that the extrusion ratio had an influence on the wear rate and that the samples extruded at a ratio of 1.6 had a lower wear resistance than the ones extruded at a ratio of 2.     

AZ31B镁合金及其纳米复合材料的滑动磨损行为(英文)

采用复合铸造工艺制备AZ31B镁合金及其纳米复合材料,再对所得材料在350°C进行热挤压。采用标准的销-盘式摩擦磨损试验机对AZ31B镁合金及其纳米复合材料的室温滑动磨损行为进行研究。实验条件为法向载荷10N、滑移速度0.60~1.2m/s、滑移距离2000m。采用SEM观察来研究磨损表面的磨损机理。通过构建一个线性回归模型来研究试验参数对磨销磨损率的影响。与AZ31B镁合金相比,由于增强体的作用而导致的硬度增强使复合材料表现出低的磨损率。犁削、犁沟、分层和氧化构成混合的磨损机理。     

Continuous control as alternative route for wear monitoring by measuring penetration depth during linear reciprocating sliding of Ti6Al4V alloy

Continuous wear monitoring during linear reciprocating sliding was investigated. Tribological tests with Ti6Al4V alloy against alumina, at nanotribometer, on microscale, were realised in dry conditions over a range of loads (100-1000 mN) and velocities (4-12 mm/s). Wear factors were calculated, for each conducted test, in two different ways. Wear factors calculated according to observed geometry of the worn tracks (according to ASTM G133 standard) were compared to values calculated according to penetration depth parameter continuously recorded by nanotribometer and results were highly correlated. Penetration depth curves and wear factor curves were obtained and analysed. Wear mechanisms based on examinations of worn surfaces by optical microscopy, were analysed in comparison with trends of penetration depth curves. Development of wear mechanism over time was further investigated. The obtained results showed that the wear factor values are strongly influenced by the applied load.     

Evaluation of sliding wear behavior of graphite particle-containing magnesium alloy composites

1 Introduction More and more magnesium alloy products have been used in automobile and aerospace industries due to their low density, high specific strength and specific stiffness, good damping characteristic, excellent machineability and castability, etc…     

Study of Wear Behavior of Zircon Sand-Reinforced LM13 Alloy Composites at Elevated Temperatures

The present article describes in detail the wear behavior of zircon sand-reinforced LM13 alloy composite at elevated temperatures with variation in load. Zircon sand particles in different amounts were reinforced into LM13 alloy by stir casting route. Dispersion of reinforced particle was examined under optical and scanning electron microscope. The hardness values of the composites were observed to increase with the increasing amount of reinforcement. The coefficients of thermal expansion of LM13 alloy and zircon sand-reinforced composites were recorded in different temperature ranges. Wear behaviors of base alloy and composites have been studied with variation in applied load. Effect of temperature (from 50 to 300 °C) on wear behaviors of both alloy and composites were determined at low (1 kg) and high (5 kg) loads. The improvement in the wear resistance was noticed with the higher amount of reinforcement. A transition from mild-to-severe wear with variations in temperature and load was observed. The results are discussed in light of operative wear mechanisms. Wear track and wear debris of composite materials were also analyzed under SEM to understand the operative wear mechanism under different conditions.     

Mechanical and dry sliding wear properties of silicon carbide particulate reinforced aluminium–copper alloy matrix composites produced by direct squeeze casting method

In this study, the microstructural features, mechanical properties and dry sliding wear characteristics of Al–4.5Cu–3Mg/15 vol.% SiCp matrix composites, manufactured by squeeze casting technique, were investigated. Wear tests were carried out at 0.5, 1 and 2.0 m/s sliding speeds under the loads of 5, 10, and 15 N for a 1000 m sliding distance versus AISI D2 steel disc. The results showed that, the composites have homogeneously distributed porosity free SiC particles. The failure in composites occurs in both matrix and particles simultaneously implying good bonding between matrix and particles. Friction coefficient of the composites decreased with an increase in the applied load and the sliding speed. In addition, the higher the applied load and the faster the sliding speed are, the higher the wear rate is. SEM analysis indicated that worn surfaces consisted of plastically deformed and oxidized particles removed by the micro-machining effects of the reinforcement phase.     

Mg3Sb2含量对Al-Mg3Sb2复相涂层耐磨性的影响

目的研究Mg_3Sb_2含量对Al-Mg_3Sb_2复相涂层的组织、硬度和摩擦学性能的影响,对比分析AZ31B镁合金基体、纯Al涂层和添加不同含量的Mg_3Sb_2之后涂层性能的差异。方法通过火焰喷涂技术在AZ31B镁合金表面制备了Al-Mg_3Sb_2复相涂层。利用扫描电镜(SEM)观察了涂层的截面形貌,利用X射线衍射仪(XRD)分析了涂层的物相组成。通过显微硬度计测试了AZ31B和涂层的硬度,通过摩擦磨损试验仪测试了AZ31B和涂层的摩擦学性能,并通过超景深三维显微镜测试了试样的磨痕宽度、深度及磨损体积。结果经火焰喷涂后可得到组织致密的复相涂层,涂层中的物相主要为Mg_3Sb_2和Al。涂层的平均硬度随Mg_3Sb_2含量的增加而增加,最高可达334.2HV0.025,是AZ31B的4.14倍。摩擦磨损试验中,涂层的摩擦系数随着Mg_3Sb_2含量的增加而减小,但都大于AZ31B的摩擦系数;涂层的磨损率随着Mg_3Sb_2含量的增加而减小,60%Mg_3Sb_2和80%Mg_3Sb_2涂层的磨损率小于AZ31B的磨损率,其他涂层的磨损率大于AZ31B的磨损率,80%Mg_3Sb_2涂层的耐磨性最好,比AZ31B下降了63.26%。随着Mg_3Sb_2含量的增加,Al-Mg_3Sb_2复相涂层的磨痕表面犁沟逐渐变浅并消失。结论 Mg_3Sb_2的加入可以提高涂层的硬度,随着其含量的增加,涂层的耐磨性逐渐提高。     

Improvement of wear resistance of wire drawing rolls with Cr-Ni-B-Si + WC thermal spraying powders

In wire drawing process, wear of rolls must be considered because of wear that influences the economics of the forming process. In this study, a nickel based matrix reinforced with WC was deposited by low cost powder welding method on low carbon steel substrates in order to determine the wear resistance of wire drawing rolls. Powder welding method includes, contrary to plasma and high velocity oxyfuel (HVOF) spraying methods, the advantages such as the single operation of powder application-fusion, simplicity, cheapness, and the ease of application. Blends of NiCrBSi and WC powders were prepared in weight proportions of WC of 40%, 45%, 50%, 55%, and 60%, respectively. Wear performance of these coatings was investigated by the dry sliding wear experiments. The wear resistance of the metal matrix composite coatings is dependent on the amount of WC. From 40% to 60%, the increase of WC is very effective on the wear resistance. The coatings with 55% and 60% of WC were worn less than the other coatings. From 55% to 60%, further increase of WC was found not to be effective for the best wear resistance. The microscopic studies of WC particles and Ni-based matrix were characterized by the scanning electron microscopy (SEM). The SEM analysis on the worn surface of coated samples shows that the matrix is considerably worn while WC particles are not considerably worn at the beginning of the wear testing. Additionally, WC particles effectively provide protection for achievement of the wear resistance at advanced periods of the wear testing.     

Mg-11Y-5Gd-2Zn镁合金干滑动的摩擦磨损行为

采用往复式摩擦磨损试验机对铸态和T6态Mg-11Y-5Gd-2Zn合金进行干摩擦磨损试验,研究载荷（3~15N）、磨擦速度（0.03~0.24m/s）、摩擦温度（25~200 °C）对合金磨损率的影响,并通过扫描电镜观察合金磨损表面形貌和磨屑。结果表明：随着载荷的增加,合金的磨损率几乎呈线性增加;随着摩擦速率的增加,合金的磨损率降低;铸态合金的磨损率高于T6态合金的。Mg-11Y-5Gd-2Zn合金中的Mg12Y1Zn1相、表面氧化相和残留的磨屑影响合金的磨损率。在本试验条件下,磨损机制主要是粘着磨损和塑性变形。     

网状陶瓷复合材料的滑动磨损行为

研究了三维连续网状多孔陶瓷复合材料在干摩擦条件下的滑动磨损行为。结果表明：复合材料的耐磨性优于基体合金;复合材料对磨环的磨损量大于基体合金对磨环的磨损量,但复合材料摩擦副的总磨损量比基体合金摩擦副的小。     

Microstructural and abrasive wear properties of SiC reinforced aluminum-based composite produced by compocasting

The effect of SiC particles reinforcement with average size of 1, 5, 20 and 50 μm and volume fraction of 5%, 10% and 15% on the microstructure and tribological properties of Al-based composite was investigated. Composites were produced by applying compocasting process. Tribological properties of the unreinforced alloy and composites were studied using pin-on-disc wear tester, under dry sliding conditions at different specific loads. The influence of secondary mechanical processing with different rolling reductions on the dry sliding wear characteristics of Al matrix composites was also assessed. Hardness measurement and scanning electron microscopy were used for microstructural characterization and investigation of worn surfaces and wear debris. The proper selection of process parameter such as pouring temperature, stirring speed, stirring time, pre-heated temperature of reinforcement can all influence the quality of the fabricated composites. The porosity level of composite should be minimized and the chemical reaction between the reinforcement and matrix should be avoided.     

原位自生(TiC+TiB)/Ti6Al4V复合材料摩擦磨损性能研究

本文用原位反应法制备了不同TiC和TiB增强相含量的(TiC+TiB)/Ti6Al4V复合材料(简记为TMC),用HT-1000型摩擦磨损试验机研究了外加载荷对原位本文用原位反应法制备了不同TiC和TiB增强相含量的（TiC+TiB）/Ti6Al4V复合材料（简记为TMC）,用HT-1000型摩擦磨损试验机研究了外加载荷对原位（TiC+TiB）/Ti6Al4V复合材料干滑动摩擦磨损性能的影响,并利用扫描电镜及布鲁克三维形貌仪观察分析其磨损行为。结果显示,与Ti6Al4V基体相比,TiC+TiB增强相的生成提高了复合材料的耐磨性。对于含不同体积分数增强相的复合材料,随着外加载荷的增加,材料的磨损率和磨损深度增加,摩擦系数减小且在小范围内波动。在小负载下,磨损的表面覆盖有一些沟槽和少量磨屑;在大负载下,磨损的表面覆盖有一些浅沟槽和大量磨屑。磨损机制为磨粒磨损和氧化磨损。随着负荷增加,碎屑的尺寸增加,磨损加剧。     

Wear properties of potassium titanate whiskers-reinforced Al-12Si alloy composites

Potassium titanate(K2O·6TiO2) whiskers-reinforced Al-12Si alloy composites were prepared by the squeeze casting technique.Wear properties of the composites were investigated by pin-on-disc tests under dry conditions.The experimental results showed that K2O·6TiO2 whiskers can effectively reinforce the matrix alloy and improve the wear resistance of the composite when the volume fraction of whiskers is low at 10 vol%.However,the composites with a high volume fraction of whiskers showed lower wear resistance than the Al-12Si alloy.The main wear mechanism of the composites is clarified as de-lamination and abrasive wear.     

高能超声场下熔体原位反应制备TiB2/Al-30Si复合材料及其耐磨性能

在高能超声场下利用熔体原位反应制备TiB2/Al-30Si复合材料;利用XRD、SEM及干磨损试验研究此复合材料的显微组织和磨损性能。结果表明：在高能超声场作用下,原位TiB2颗粒在铝基体中分布均匀,形貌为圆形或四边形,尺寸在0.1-1.5μm之间。初生硅的形貌为四边形,平均尺寸为10μm。随着高能超声功率的增加,Al-30Si基体合金及TiB2/Al-30Si复合材料的硬度明显提高;特别是当超声功率为1.2 kW时,复合材料的硬度达到412 MPa,是基体合金的1.3倍。复合材料的磨损性能得到明显提高,载荷的变化对复合材料的磨损量影响不大。     

Tribological Properties of Nanostructured Al/Al_(12)(Fe,V)_3Si Alloys

Tribological behavior of nanostructured pure Al and Al–Al12(Fe,V)3Si alloys containing 27(FVS0812) and 37(FVS1212) vol% of Al12(Fe,V)3Si precipitates was investigated. All samples were prepared using mechanical alloying followed by hot pressing. Wear tests were performed at room temperature using a pin-on-disk machine. Results showed that the presence of Al12(Fe,V)3Si precipitates increases the wear resistance of nanostructured Al, and the wear resistance increases with increasing the Al12(Fe,V)3Si content. Scanning electron microscopy images of worn surfaces and wear debris demonstrated that abrasion and adhesion are the governing wear mechanisms for the nanostructured FVS0812 alloy at 2 and 5 N normal loads, whereas for the nanostructured FVS1212 alloy, the dominant wear mechanism is abrasion at these loads. A mechanically mixed layer(MML) containing Fe and O was formed on the worn surfaces of FVS0812 and FVS1212 samples at 10 N normal load. Formation and delamination of MML controls the wear behavior of these samples at the normal load of 10 N. It is also found that the presence of Al12(Fe,V)3Si precipitates decreases the friction coefficient of nanostructured Al.