深冷处理对钛合金力学性能及摩擦磨损性能的影响

为了探究深冷处理对TC4钛合显微组织,力学性能及摩擦磨损性能的影响,采用显微硬度计测定钛合金的表面硬度,光学显微镜观测钛合金经深冷处理后微观组织的变化,万能拉伸试验台测定其拉伸性能,利用摩擦磨损仪研究了深冷处理前后钛合金的磨损性能及利用SEM、EDS分析磨痕的微观形貌和化学成分.结果 表明:深冷处理可以提高TC4钛合金...     

Effects of Mechanical Properties on the Wear Resistance of Journal Bearing Alloys

Sample quantities of eight bearing alloys were produced in thick (> 5mm) plates with microstructures similar to those obtained in the thin layers of automotive journal bearings. These materials consisted of four sintered leaded bronze alloys containing various amounts of lead and tin, a cast leaded bronze alloy, a cast lead babbitt, and a wrought aluminum-silicon alloy, in both the prior-to and after precipitation hardened conditions. Specimens machined from these sample plates were used in tensile, hardness, and wear experiments. Tensile tests were conducted at two temperatures and two strain rates. In order to eliminate the chemical effects of lubricant additives on tribological performance, wear experiments were conducted with a base oil containing no additives. As such, only the effects of the bulk characteristics of the bearing alloys on wear behavior were evaluated experimentally. Correlative analysis by both a graphic method and standard statistical computer technique were employed to identify parameters which affect wear resistance. Bulk material properties such as hardness, strength, ductility, temperature sensitivity, and strain rate sensitivity were found to contribute only secondary effects on the wear rates of specific alloy families. Adhesive wear behavior was found to be dependent on the transfer characteristics of the materials tested in all cases.     

Investigation of an Approach to Balance Wear Resistance and Mechanical Properties of Crosslinked UHMWPE

In order to produce ultra-high molecular weight polyethylene (UHMWPE) with increased wear resistance for bearing applications, yet minimize degradation in stiffness and oxidation resistance, the authors have proposed irradiation crosslinking of the polymer at moderate radiation doses. It was theorized that this would minimize or eliminate the need for a subsequent stabilization of free radicals, and thus retain a significant proportion of the original stiffness of the crystalline polymer. In this study, four groups of UHMWPE were investigated: (a) non-crosslinked, (b) crosslinked with 50 kGy electron-beam irradiation, thermally stabilized, (c) crosslinked, non-stabilized, and (d) crosslinked, non-stabilized, and exposed to accelerated oxidation to simulate prolonged exposure. Crosslinking and subsequent thermal stabilization significantly reduced the elastic modulus of UHMWPE, while omission of the stabilization step yielded a more moderate reduction in elastic modulus. It was shown that thermal stabilization reduced crystallinity more so than did omission of stabilization. Accelerated aging did not further decrease the storage modulus of UHMWPE over that of non-stabilized, non-aged polymer. Crosslinking showed a significant increase in wear resistance, while aging of the non-stabilized polymer showed no adverse effects on wear. These results suggest the potential for the use of moderate UHMWPE crosslinking without stabilization for industrial and some biomedical applications.     

A Mixed Friction Hydrostatic Mechanical Face Seal Model with Thermal Rotation and Wear

A mixed friction model is presented for the mechanical face seal. The model considers load sharing between mechanical and fluid hydrostatic pressures and the friction that results. Thermal rotation resulting from friction heating is included. Equilibrium solutions are presented which show a strong influence of thermal rotation on initial seal performance. A wear model shows that seal faces wear parallel after a period of steady operation in spite of initial taper. The model can be used to simulate seal performance over a period of time and under variable operating conditions.     

原位合成(TiB2+Fe2B)/铁基复合材料的力学性能和耐磨性

在含0.15%~0.45%C,0.20%~0.50%Si,0.60%~1.20%Mn和0.50%~1.50%Cu的Fe-C合金中加入硼和钛,原位合成了颗粒增强铁基复合材料。借助光学显微镜、扫描电镜和X衍射分析等手段,分析了颗粒增强相和基体组成;采用冲击试验机、材料试验机和磨损试验机等测试了复合材料的力学性能和耐磨性。研究发现,铁基复合材料的原位合成增强相是TiB2和Fe2B,且以TiB2为主。热处理后,铸态时呈条块状和针状的增强相变成团球状和颗粒状,使复合材料力学性能改善,耐磨性提高,并分析了原位合成颗粒增强相改善材料性能的原因。     

高耐磨精铸热作模具钢的热性能研究

研制了一种高耐磨精铸热作模具钢,分析了其热稳定性、热疲劳性能、耐铝热熔损性能和热磨损性,并与H13钢进行了对比.结果表明:经440 ℃或600 ℃回火后,研制的高耐磨精铸热作模具钢的硬度为HRC 40～45, 其热稳定性与H13钢相当,热疲劳抗力、耐铝热熔损性和热耐磨性均高于H13钢.     

等离子喷涂陶瓷涂层的动态防滑性能和耐磨性

采用等离子喷涂技术制备Al2O3-13%Ti O2和WC复合涂层。利用MMS-1G高速摩擦试验机评价涂层在高速动态条件下防滑性能和耐磨性,并分析涂层的磨损机制。结果表明:所有涂层防滑性能随着速度和载荷的增加而下降,在相同条件下WC涂层的防滑性能最好,但Al2O3-13%Ti O2涂层耐磨性要好于WC涂层;所有涂层磨损率均随载荷和速度增加呈现上升趋势,Al2O3-13%Ti O2涂层磨损机制以黏着磨损和层片剥落为主,而裂纹扩展引起的脆性断裂则主导了WC涂层的磨损机制。     

纳米氧化铝对聚甲醛力学性能及摩擦磨损性能的影响

用双螺杆挤出机制备了纳米氧化铝改性聚甲醛材料,研究了纳米粒子在基体中的分散状态、复合材料的力学性能及摩擦磨损性能.结果表明:纳米粒子在基体中基本达到了纳米级的分散;纳米氧化铝的加入使材料变脆,但刚性增强,聚甲醛纳米复合材料的干摩擦性能降低,磨损的主要机理为磨粒磨损,聚甲醛纳米复合材料的油摩擦性能得到了显著提高.     

船舶艉轴机械密封材料摩擦磨损性能研究

为探究船舶艉轴机械密封用高分子材料在实际工作环境下的摩擦磨损性能,选用浇注型聚氨酯弹性体（CPU）、聚对苯二甲酸乙二醇酯（PET）、聚对苯二甲酸丁二酯（PBT）、玻璃纤维改性聚己二酰丁二胺复合材料（GF/PA46）与玻璃纤维改性聚四氟乙烯复合材料（GF/PTFE）5种材料,在载荷为0.5 MPa,线速度为7 m/s的工况下开展摩擦磨损性能测试。结果表明：重载、高速的工况使得CPU、PET、PBT、GF/PA46材料出现了不同程度的剥落与犁沟,摩擦因数与磨损量较大;GF/PTFE材料仅出现一些相对轻微的撕裂和磨痕,相较于CPU、PET、PBT、GF/PA46材料,GF/PTFE的平均摩擦因数分别下降了66.6%、80.4%、86.1%、87.8%,单位时间磨损量分别下降了91.7%、92.7%、88.6%、97.0%,摩擦磨损性能最优。     

耐磨性和机加工性优良的药芯焊丝

研究了一种堆焊药芯焊丝，按通常工序制造与修复轧辊等设备，具有焊态机械加工性好，消除应力处理后硬度高、耐磨性好等特点，较好地处理了硬度、耐磨性和机加工性之间的矛盾。对其设计原理、具体的应用进行了阐述。     

热喷涂技术提高活塞杆耐磨和耐腐蚀的方法

液压油缸被应用于不同的行业和领域,这就要求它需要在复杂的环境中保持自身的性能,而液压油缸的活塞杆常常因为划伤、磨损和腐蚀等原因导致失效.目前市场上常用的方法是通过镀铬提高其耐磨和防腐性能,但镀铬工艺环境污染严重,在欧洲一些国家已经禁止六价铬的使用.该文主要介绍利用热喷涂涂层技术提高活塞杆耐磨和耐腐蚀性能的方法.     

K360耐磨钢堆焊合金层的组织与性能

利用药芯焊丝对已磨损的K360耐磨钢进行CO2气体保护堆焊修复,并对堆焊层进行了显微组织、X射线衍射、硬度、冲击韧度及抗磨料磨损性能试验.结果表明:堆焊层的组织为细小板条马氏体 少量弥散分布碳化物,硬度不高,产生冷裂纹倾向小,韧性与塑性较高;同时堆焊层组织细小,弥散分布的碳化物对焊层基体有强化作用,使堆焊层的耐磨性达到了基体的水平.     

改进的BP算法在磨粒识别中的应用

本文提出用改进的神经网络算法,建立适于磨粒分析的AWPRM模型,设计了智能磨粒识别分类器,实例表明,用该方法可以准确识别磨粒类型,并具有较好的推广能力。     

改进的BP算法在磨粒识别中的应用

提出了用隐层和输出层的权值单独修改的方法来改进神经网络算法，建立了适于磨粒的分析模型，设计了智能磨粒识别分类器。实例表明，用该方法可以准确识别磨粒类型，并具有较好的推广能力。     

Wear Resistance of Amorphous-Crystalline Coatings with Lubricants

The results of tests of a Zr–Al–B boundary friction detonation coating in a wide range of changes under friction conditions have been presented. A comparative analysis of the obtained characteristics of friction and wear in order to evaluate the tribotechnical properties of amorphous-crystalline coatings has been carried out. These results have been compared with parallel tests of coatings based on tungsten carbide, samples of hardened steel and bronze, and the bearing of the sliding layer. The formation of solid solutions has been established and the introduction of oxygen in zirconium that corresponds to the formation on the friction surfaces of the secondary structures of the first type, a characteristic feature of which is their surface localization, ultra-dispersed structure, and ability to minimize disruption and shield unacceptable adhesion phenomena. The use of the Auger electron microscope confirmed that oxygen completely replaces the sulfur in the surface structures.     

动态力学热分析法测定合成薄膜的力学性能

讨论了动态力学热分析测试方法，并利用强迫非共振拉仲模式测定了厚度为37μm的聚酰亚胺／二氧化硅合成薄膜的力学性能。文章给出了测得的动态杨氏模量随温度的变化曲线，得到了较为满意的结果。     

高导电耐磨铜基复合材料的研究

用冷压-烧结-热挤压工艺制备了SiCp／Cu复合材料，得到组织均匀、致密、导电导热的复合材料。干磨损试验结果表明，随着SiC含量的提高，复合材料具有更高的耐磨性；SiC颗粒增强物的加入减小了材料的粘着磨损，使复合材料在高载荷条件下具有更为优越的耐磨性。SiC体积分数不超过15％的铜基复合材料具有比铬锆铜合金更高的导电、导热性能和耐磨性。     

Existence of Good Bonding between Coated B4C Reinforcement and Al Matrix via Semisolid Techniques: Enhancement of Wear Resistance and Mechanical Properties

An Al 6061 alloy matrix reinforced with the coated B₄C particles was used for the present study. The cohesion of the reinforcing ceramic particles is poor at temperatures near the melting point of aluminum and leads to inferior mechanical and tribological properties of developed aluminum matrix composites with nonuniform distribution of the reinforcement. The main reason for coating the particles is to improve the bond between the reinforcement and molten alloy and thus to eliminate interfacial reactions. The great enhancement in strength values of the composites in this study can be ascribed to the effective load-bearing capacity of disintegrated B₄C particles that are adherently bonded to the matrix alloy. Homogeneity and reduction in the particle size of B₄C during the extrusion process is evidenced in the microstructural studies.     

机械合金化FeS/Cu复合材料的摩擦磨损性能

以FeS和CuSn8Ni1粉末为原料,利用机械合金化技术和粉末冶金技术制备了FeS/Cu复合材料,探讨了不同载荷情况下所制备的FeS/Cu复合材料的摩擦学性能及润滑膜与转移膜特征。结果表明：机械合金化提高了FeS与铜合金基体界面结合性能,进而提高了材料减摩耐磨性能;当载荷较小时,摩擦副表面接触不稳定,复合转移膜不连续,摩擦因数波动大;载荷较大时,复合转移膜易破损,材料的减摩耐磨性能变差;当载荷为150 N时,载荷适宜,材料表面软化,复合转移膜更加完整,摩擦因数较小。     

钛合金表面硅电极电火花强化及其耐磨性能

用硅电极分别在空气和硅油中对钛合金表面进行了电火花沉积强化改性。利用扫描电子显微镜、X射线衍射仪、辉光放电光谱仪分析了改性层的形态、结构和成分分布,采用显微硬度计测试了改性层的硬度分布,通过电化学极化曲线和交流阻抗技术测试评价了改性层的耐蚀性,利用球-盘磨损试验机研究了改性层的耐空气环境磨损与耐NaCl水溶液腐蚀磨损性能。研究结果表明:硅电极在空气中电火花强化Ti6Al4V合金表面,形成约40μm厚合金化改性层,主要物相为Ti5Si3、TiSi2、Si和TiN,硬度达2180HK。硅电极在硅油介质中电火花强化Ti6Al4V合金表面,形成约40μm厚的合金化改性层,主要物相为Ti5Si3、TiSi2和TiC,硬度达1810HK。硅电极电火花强化改性层的组成和硬度沿层深均呈梯度变化。硅电极电火花强化改性层显著提高了钛合金基材的抗空气环境干磨损性能,显著提高了钛合金基材的耐NaCl水溶液腐蚀磨损性能。