高铬铸铁耐磨材料在泥沙磨损条件下耐磨性影响因素分析

分析了碳化物形态与分布、基体组织和稀土变质处理对高铬铸铁耐磨材料在泥沙磨损条件下的耐磨性影响。结果表明 :碳化物的形态和分布对高铬铸铁的耐磨性有直接影响 ,块状或短杆状且分布均匀的碳化物对提高材料的耐磨性有利 ,网状或长针状碳化物对耐磨性不利 ;在泥沙磨损试验条件下 ,提高高铬铸铁中基体组织的显微硬度和基体组织与碳化物的结合强度有利于提高高铬铸铁材料的耐磨性 ;稀土元素的加入 ,使高铬铸铁的晶粒细化 ,碳化物颗粒变得细小 ,分布更为均匀 ,有利于提高高铬铸铁在泥沙磨损条件下的耐磨性。

磨损条件对冷作模具钢的磨粒磨损特性及机理的影响

本文通过对三种冷作模具钢LDI、65Nb和Cr12MoV在不同磨损条件下的磨粒磨损试验,并结合金相组织分析和SEM形貌观察,研究了试验钢的磨粒磨损特性,讨论了钢的组织和力学性能对耐磨性的影响。结果表明:材料的磨损机理随磨损条件的变化而变化;LDI钢540℃两次回火组织具有优良的耐磨性。

Schallamach图纹与橡胶性能和磨损条件的关系

引言1952年 Schallamach 进行的有关橡胶磨损方面开拓性的工作表明,在平滑磨耗试验中产生的磨损图纹与所施加的摩擦应力垂直。此后。

30CrMnSiA钢的摩擦磨损性能研究

采用MMS-2A型摩擦磨损试验机对不同热处理后的30CrMnSiA钢进行摩擦磨损性能实验,并分析磨损条件对其磨损性能的影响规律。结果表明:在其他磨损条件不变,只改变其中一个磨损条件(即磨损距离或磨损速度或载荷)时,随着磨损距离或磨损速度或载荷的单独增加,经不同热处理后的30CrMnSiA钢件的磨损质量损失均增大。

含WC纳米微粒的镍基复合镀层的滑动磨损机理研究

本文通过对含WC纳米微粒的镍基复合镀层在干摩擦滑动磨损条件下，磨损失重、施加载荷、滑动距离、镀层种类之间的正交实验及对磨损表面的显微分析及形貌观察，发现在不同的磨损条件下，复合镀层的磨损表面的显微形貌有很大的不同。实践证明，在不同的干摩擦磨损条件下，可能发生粘着磨损，也可能发生犁削磨损，或两者同时发生。

镍钛合金应力诱发相变下的微磨损机理研究

研究内容：镍钛形状记忆合金具有功密度高、输出力和位移大等突出优点，是研制微机电系统驱动器（MEMS）的理想材料。针对其相变相关的微磨损问题，本项目循着从压痕、划痕到磨损的研究思路，试验研究了不同温度下镍钛合金应力诱发相变对其变形和磨损的影响，并建立了不同工况下的零磨损条件。结果表明：①随温度的增加，镍钛合金硬度表现出一种非线性增加的趋势。②在给定的温度下，存在着一个磨损临界载荷，低于此载荷，基本无磨损发生。

机械零件摩擦磨损的自修复

摩擦学的发展已将摩擦磨损的研究从抗磨减摩扩展到了磨损表面的自修复甚至是零磨损。文中对摩擦磨损表面自修复的概念进行了阐述,详细论述了自发摩擦磨损和条件摩擦磨损的集中类型和实现模式,指出纳米技术的发展有望在摩擦表面建立起一层自组装的、坚固的、自修复的润滑膜,为摩擦磨损表面自修复提供了切实的途径。

踝关节假体磨损测试及仿真研究进展

假体磨损造成的无菌性松动是人工踝关节失效的主要原因,而人工踝关节磨损的模拟机测试和数值仿真是临床前评估假体磨损性能的重要方法。本文对国内外踝关节假体磨损研究中采用的力学和运动学曲线进行了对比,并对相关研究结果进行总结、归纳和分析。结果表明:①早期研究没有ISO测试标准,造成各研究的加载条件主要在轴向载荷和前后位移上存在差异,因此很难通过横向对比得到踝关节假体的磨损规律。②国外研究了踝关节假体的设计、材料、测试条件及润滑介质等因素对磨损测试结果的影响,然而国内暂未检索到相关文献发表。③人工踝关节磨损的数值仿真结果与体外测试结果相近,这表明经验证的磨损模型能够用于预测踝关节假体的磨损性能。

运用表面工程技术降低设备维修费用

城区排水泵站的机械设备多在腐蚀与磨损条件下运行，机械部件失效较快。本文介绍了通过运用表面工程技术修复多种机械部件来降低设备维修费用的经验。

防腐蚀涂料

醇酸树脂型耐磨防腐蚀涂料组合物 本发明涉及在化学品侵蚀介质中磨损条件下运作的腐蚀性金属表面的保护与修复。该涂料组合物由改性的醇酸树脂21%～35%、脂肪胺型表面活性剂（作流变助剂）1％～2％、催干剂0．5％～1．0％、填料4％～12％、磷酸锌5％～10名、丹宁型锈转化剂1％～3％、三氧化二铁含量高的粒度≥163μm的镜铁矿20％～30％和粒度≤20μm的镜矿石6％～15％，以及有机溶剂（至平衡量为100％）构成。

Microstructure and abrasion wear behavior of Ni-based laser cladding alloy layer at high temperature

Ni-based alloy coating on 21-4-N heat-resistant steel was prepared using CO2 laser, and the high-temperature abrasion wear was tested. The microstructure of this cladding layer and its abrasion wear behavior at high temperature by changing compositions and temperatures were investigated by means of optical microscope and scanning electron microscope. Among the three compositions of cladding layer, i.e. Ni21+20%WC+0.5%CeO2, Ni25+20%WC+0.5%CeO2 and Ni60+20%WC+0.5%CeO2, the experimental results show that Ni21+20%WC+ 0.5%CeO2 cladding layer is made up of finer grains, and presents the best abrasion wear behavior at high temperature. The wear pattern of laser cladding layer is mainly grain abrasion at lower temperature, and it would be changed to adhesive abrasion and oxide abrasion at higher temperature.

Effect of applied load on transition behavior of wear mechanism in Cu-15Ni-8Sn alloy under oil lubrication

Tribological behavior of Cu-15Ni-8Sn(mass fraction, %) alloy against GCr15 ring under various loads was investigated on a ring-on-block tester in oil lubrication. The results showed that the wear rate increased slowly from 1.7×10^(-7) to 9.8× 10^(-7) mm^3/mm under the load lower than 300 N, and then increased dramatically to the climax of 216×10^(-7) mm^3/mm under the load over 300 N, which indicated the transition of wear mechanism with the increase of applied load. The wear mechanism mainly was plastic deformation and abrasive wear under the load less than 300 N. As the applied load was more than 300 N, the wear mechanism of Cu-15Ni-8Sn alloy primarily was delamination wear. Besides, the transition can also be confirmed from the different morphologies of worn surface, subsurface and wear debris. It is distinctly indicated that the appearance of flaky debris at the applied load over 300 N may be a critical point for the change of wear mechanism.

Wear mechanism for spray deposited Al-Si/SiC_p composites under dry sliding condition

Al-Si/15%SiCp(volume fraction) composites with different silicon contents were fabricated by spray deposition technique, and typical microstructures of these composites were studied by optical microscopy(OM). Dry sliding wear tests were carried out using a block-on-ring wear machine to investigate the effect of applied load range of 10-220 N on the wear and friction behavior of these composites sliding against SAE 52100 grade bearing steel. Scanning electron microscopy(SEM) and energy-dispersive X-ray microanalysis(EDAX) were utilized to examine the morphologies of the worn surfaces in order to observe the wear characteristics and investigate the wear mechanism. The results show that the wear behavior of these composites is dependent on the silicon content in the matrix alloy and the applied load. Al-Si/15%SiCp composites with higher silicon content exhibit better wear resistance in the applied load range. Under lower loads, the major wear mechanisms are oxidation wear and abrasive wear for all tested composites. Under higher loads, severe adhesive wear becomes the main wear mechanisms for Al-7Si/15%SiCp and Al-13Si/15%SiCp composites, while Al-20Si/15%SiCp presents a compound wear mechanism, consisting of oxidation, abrasive wear and adhesion wear.

Optimization of shearer sliding boots by plasma cladding with Cr_4MnTi

Severe production conditions in coal mines cause damage and failure problems with the oriented sliding boots of the mechanical shearer. Wear has been an especially vexing problem. Plasma cladding methods were used to study optimized sliding boot design. By cladding the substrate steel the surface may be made of a material more resistant to wear. The iron based alloy Cr4MnTi was coated onto a modified 45 steel matrix material in these tests. The results show that the alloy cladding layer is high strength, has high hardness, and is highly resistant to wear. After hardening and tempering, 45 steel substrate has great tenacity so the combined structure meets the performance requirements for the construction of shearer sliding boots.

Evaluation on Pipao＇ s Construction Comfort by Fuzzy Theory

Comfort is one of the most important attributes demanded by bra consumers. It reflects the psychological feeling of a wearer.Different kinds of knitted fabric are chosen as bra samples in this paper. This subject studied the bra＇s comfort sensations by carrying out a series of subjective wear at temperature at 21± 2℃ and humidity of 65±3%. By exploratory analysis of the subjective ratings on 3 mainly sensory factors （thermal, moisture and tightness）, the relationships between 3 factors are studied under three conditions, before, during and after movement. This study is focused on subjective evaluation ofbra＇ s comfort sensations of made of different knitted fabrics. Finally, based on fuzzy theory, the comprehensive comfort sensations of these fabrics in different wear conditions are analyzed and evaluated.

Effect of extrusion on properties of Al-based composite

An aluminium alloy and its composite with dispersed SiC particles made by liquid metallurgy route were extruded under optimized conditions.The properties were characterized in terms of microstructure,hardness and sliding wear behaviour and then compared between the extruded and cast alloys and composites,in order to understand the benefits of composite and extrusion on the alloy.It was observed that composites drastically increased the hardness and the extruded composites further increased this value.The advantage of composites was realized in sliding wear tests.

近精冲工况下的模具磨损测试装置设计与分析

精冲模具对精密性要求很高,研究模具磨损实验过程中需要多次拆卸,影响装配精度,从而影响磨损实验结果。基于精冲模具磨损分析,提出采用板料挤压模具的方式来研究精冲模具磨损。将板料挤压模具与目前市场上常用的磨损试验机进行对比发现,板料挤压模具更接近精冲模具磨损条件,测得的数据量更为丰富。基于有限元模拟软件对板料挤压与精冲模具在成形过程中的受力情况进行模拟比较发现,一定挤压截面比下,板料挤压模具与精冲模具磨损受力近似相同,可以用板料挤压实验来等效精冲模具磨损的研究。在此基础上,给出了带压边的挤压模具结构设计,可用于精冲模具磨损机理的进一步研究。