磨煤机内部冲蚀磨损的解决方案

运用冲蚀磨损的机理,对磨煤机内部冲蚀磨损进行了分析,并提出了降低冲蚀磨损的方案。分析表明,该方案可实施性强,应用价值高。     

热处理对原位烧结(Ti,V)C钢结硬质合金组织及耐磨性的影响

利用粉末冶金技术,原位烧结合成了(Ti,V)C钢结硬质合金,并用扫描电镜、X射线衍射仪等研究了热处理对原位烧结(Ti,V)C钢结硬质合金组织和耐磨性的影响。结果表明:烧结态(Ti,V)C钢结硬质合金基体组织为细珠光体组织;1 000℃淬火后的组织转变为片状马氏体+(Ti,V)C硬质相颗粒+少量未溶碳化物;回火过程中合金具有较高的抗回火稳定性,在500℃左右回火时存在二次硬化现象;该合金在1 000℃淬火、经250,500℃回火后具有较好的耐磨性。     

润滑油含磷添加剂结构表征和齿轮机试验中热稳定性研究

利用气质联用、质谱和核磁验证润滑油添加剂T306（磷酸三甲酚酯）和T310A（硫代磷酸酯胺盐）的组成和结构,并采用核磁共振磷谱(31P-NMR)检测齿轮机试验前后润滑油中磷系添加剂结构的变化。研究表明,T306具有优异的热稳定性和抗磨性,适用于高温的工况; T310A具有较好的氧化安定性、抗摩擦能力和磷保持能力,适用于温度高、周期长的苛刻工况。不同的含磷添加剂热力学稳定性不同,所适合的工况也存在差异。利用核磁共振磷谱可以判断不同含磷添加剂所适用的工况以及在该工况条件下添加剂的结构变化情况,从而可通过对含磷添加剂的监测来判断油品的质量。     

基于逆向工程技术的天然牙磨损量测量研究

由于天然牙牙冠磨损量微小且形貌复杂,传统的测量方法难以精确获得磨损量。提出采用基于逆向工程技术的天然牙磨损量测量方法。首先通过三维扫描仪获取磨损实验前后的天然牙点云数据,其次采用逆向工程软件Geomagic studio中的最近点迭代ICP(Iterative Closest Point)算法将磨损前后的天然牙点云数据对齐,在此基础上通过3D比较和体积计算,测算出磨损区域的最大磨损高度、平均磨损高度和磨损体积3个磨损特征量。结果表明,该方法能够较为准确地实现天然牙磨损量的测量,同时再现磨损区域的空间几何形状,实现磨损量测量过程的数字化、定量化和可视化。     

Analysis on collapse strength of casing wear

Carrying capacity of the casing will reduce after the casing is worn, which seriously affects the subsequent well drilling, well completion, oil extraction and well repair. A lot of researches on calculation of casing wear collapse strength have been done, but few of them focus on collapsing failure mechanism, and influencing factors and law of collapse strength. So, significant difference between estimated value and actual value of collapse strength comes into being. By theoretical analysis, numerical simulation and actual test, the collapsing failure mechanism of casing wear as well as the influencing factors and laws of collapse strength are investigated, and the investigation results show that collapse of crescent casing wear belongs to "three hinged" instability. The severely-worn position on the casing is yielded into the plastic zone first then deformed greatly, which causes the plastic instability of the whole structure. The casing wear collapse strength presents changes of exponent, power function and linear trend with the residual casing wall thickness, wear radius and axial load, respectively. When the flexibility is less than 10°/30 m, the borehole bending has less impact on casing collapse strength. Thus, the computation model for the casing wear collapsing strength is established by introducing wear radius coefficient and casing equivalent yield strength, at the same time, the model is tested. The test results show that the relative error for the computation model is less than 5%. The research results provide a basis for design of the casing string strength and evaluation of down-hole safety.     

基于遗传算法改进的BP神经网络模型的磨损机理智能识别

通过提取磨粒形状特征参数、颜色特征参数和表面纹理等特征参数对磨粒形态进行量化表征,并以此为输入矢量,引入遗传算法(GA)改进BP神经网络对磨粒进行自动分类识别,建立遗传算法改进的BP神经网络模型,并给出具体的算法实现过程。分别应用遗传算法改进的BP神经网络模型和未引入遗传算法改进的BP神经网络模型对磨粒图像进行智能识别。实验结果表明,遗传算法改进的BP神经网络综合了遗传算法的全局优化和BP算法局部搜索速度快的特点,网络识别率较高,具有较好的全局性。     

Friction and wear behavior of human teeth under various wear conditions

Previous reports have described the differences in the friction and wear behavior between different zones of human teeth. The objective of this research was to study the friction and wear behavior of human teeth under different wear conditions to extend the understanding of the tooth wear process, as well as to provide a more rational explanation for wear mechanism of teeth. Two typical wear tests, namely two- and three-body wear, were conducted on human tooth enamel using a reciprocating apparatus. The effect of food particles was of particular interest. Three loads, 10, 20 and 40 N, were used. Wear was assessed by sample wear volume. The results show that human tooth enamel exhibits lower friction and smaller wear volume under three-body wear conditions than under two-body wear conditions. Under three-body wear conditions, although increasing normal load results in a progressive increase in the wear volume of enamel, the increasing rate is lower at high load than that under two-body wear conditions. Further analysis of wear surfaces indicates that human tooth enamel experiences different wear mechanisms under different wear conditions.     

微型电动机轴承磨损寿命试验分析

通过轴承寿命试验前后性能与表面形貌等对比测试分析,总结了轴承性能与表面形貌等随寿命试验变化的规律及关系,并给出了轴承磨损寿命计算公式及可靠度,同时指出了影响轴承磨损寿命的主要因素。     

双金属轴承材料表面黏结润滑涂层摩擦学性能研究

在HDM-10型端面摩擦磨损试验机上进行油润滑及规律变载条件下的摩擦磨损试验,考察了石墨﹑MoS2及其复合黏结润滑涂层的摩擦磨损性能.结果表明:固体润滑涂层显示了较好的减摩耐磨性能,摩擦副正常阶段的摩擦系数在0.09以下,摩擦温升小,涂层的承载载荷都超过了2 800 N,最高达到4 800N;石墨与MoS2有较好的协同效应,当石墨、MoS2与胶黏剂的比例为3∶ 2∶ 10时,涂层的摩擦学性能最佳.     

不同激光熔覆材料涂层的耐磨性能比较

本文研究了宽带激光熔覆不同熔覆材料的复合涂层的耐磨性能。结果表明:Ni60B熔覆层的硬度高于40Cr基材的硬度,Ni60B+WC梯度复合涂层具有最高的硬度,对于提高零件的抗磨损性能比较有利;Ni60B熔覆层和Ni60B+WC熔覆层均适合修复轴类零件;三层梯度复合涂层磨痕宽度最小,具有最好的耐磨性。