Analysis of surface integrity for minimum quantity lubricant—MQL in grinding

The quality of machined components is currently of high interest, for the market demands mechanical components of increasingly high performance, not only from the standpoint of functionality but also from that of safety. Components produced through operations involving the removal of material display surface irregularities resulting not only from the action of the tool itself, but also from other factors that contribute to their superficial texture. This texture can exert a decisive influence on the application and performance of the machined component. This article analyzes the behavior of the minimum quantity lubricant (MQL) technique and compares it with the conventional cooling method. To this end, an optimized fluid application method was devised using a specially designed nozzle, by the authors, through which a minimum amount of oil is sprayed in a compressed air flow, thus meeting environmental requirements. This paper, therefore, explores and discusses the concept of the MQL in the grinding process. The performance of the MQL technique in the grinding process was evaluated based on an analysis of the surface integrity (roughness, residual stress, microstructure and microhardness). The results presented here are expected to lead to technological and ecological gains in the grinding process using MQL.     

消除磨齿裂纹的工艺措施

介绍了磨齿裂纹的产生机理，给出了防止磨齿裂纹产生的工艺措施，收到了良好的效果。     

宝钢热轧厂轧辊磨床的技术改造

介绍了宝山钢铁股份有限公司热轧厂对其轧辊磨床进行床身导轨、数控系统、测量系统、中心架、砂轮主轴及动平衡装置、集中控制、在线涡流探伤等方面的技术改造情况。改造后，磨床精度、效率和稳定性明显提高。     

钨合金的磨削加工去除机理

目的 解决钨合金磨削加工去除机理不明晰的问题。方法 基于单磨粒刻划有限元仿真、单磨粒刻划和磨削加工实验，探究钨合金的磨削加工去除机理。结果 在刻划过程中，划痕的不同位置材料的去除特性存在显著差异。在单颗粒刻划切入端，材料依次发生了塑性变形、隆起、微裂纹，再到钨相与黏结相的混杂交融。在划痕中段以材料去除为主，出现了材料微卷起和材料卷起现象，沿着刻划方向卷起现象越来越严重。在划痕切出端，划痕边缘和尾部均出现了“飞边”现象，且相较于切入端，切出端的形貌较差，实验与仿真吻合。此外，在不同相位处，材料的去除特性也存在一定不同。在钨相区域，同时存在脆性特征和塑性特征。在黏结相区域，刻划深度较浅时主要呈现塑性变形、塑性流动等特征，刻划中端深度较大时主要呈现与钨相的混杂和交融。在钨相与黏结相的相界处，相邻钨颗粒呈现不同的损伤或去除特征，且相界会阻断特征形貌的传递。最后，磨削后的钨合金表面存在单颗粒刻划痕上出现的所有去除特征，与单颗粒划痕的去除特征吻合。不同的是，磨削后划痕底部出现了区域性和放射状的裂纹。结论 钨合金的两相特性使得磨削表面的去除特征较复杂，存在塑性变形、微裂纹、微卷起、卷起、裂纹和两相交...     

An efficient method for solving the Signorini problem in the simulation of free-form surfaces produced by belt grinding

Industrial robots are recently introduced to the belt grinding of free-form surfaces to obtain high productive efficiency and constant surface quality. The simulation of belt grinding process can facilitate planning grinding paths and writing robotic programs before manufacturing. In simulation, it is crucial to get the force distribution in the contact area between the workpiece and the elastic contact wheel because the uneven distributed local forces are the main reason to the unequal local removals on the grated surface. The traditional way is to simplify this contact problem as a Signorini contact problem and use the finite element method (FEM) to calculate the force distribution. However, the FEM model is too computationally expensive to meet the real-time requirement. A new model based on support vector regression (SVR) technique is developed in this paper to calculate the force distribution instead of the FEM model. The new model approximates the FEM model with an error smaller than 5%, but executes much faster (1 s vs 15 min by FEM). With this new model, the real-time simulation and even the on-line robot control of grinding processes can be further conducted.     

新型钢管内外圆修磨机的技术特点

介绍上海西重所重型机械成套有限公司开发研制的内外圆钢管修磨机的设备组成、技术特点及其使用情况,整机的技术性能已达到国外同类设备的先进水平,特别是能适应环境保护的要求,对钢管修磨后产生的多种粉尘有收集功能.可在国内众多钢管厂推广应用.     

成型砂轮截面曲线光顺处理的近似双圆弧插补法及误差估算

在解决成型砂轮截面曲线的光顺处理问题时，作者提出了一种新的曲线数字化处理方法——近似双圆弧插补法，简化了计算过程。为了估算该方法的误差，本文模拟曲线反求的过程进行了仿真计算，计算结果表明：若曲线反求时测量点的间距取为0．1mm左右，则对所讨论的实例而言，处理结果对原曲线的最大偏离为0．552μm，这样的误差对数控加工影响很小，而且整个处理过程所花费的时间不足1分钟，因此，该方法能满足数控加工的要求。     

声光调Q Nd:YAG脉冲激光修锐树脂结合剂CBN砂轮

采用声光调Q Nd:YAG脉冲激光径向辐照，对树脂结合剂CBN砂轮进行修锐试验研究。研究了单脉冲激光辐照下，平均功率，脉冲频率和离焦量等参数对烧蚀凹坑深度的影响，由此可方便获得合适的激光修锐参数；分析了声光调Q YAG脉冲激光修锐树脂CBN砂轮的选择性去除机理，观察并比较了声光调Q脉冲激光，连续激光和机械法修锐后砂轮表面的地形地貌，试验表明声光调Q Nd:YAG脉冲激光径向辐照修锐树脂CBN砂轮，可获得更为良好的修锐效果。     

不锈钢研磨材料及研磨工艺

论述了不锈钢研磨用材料及其对研磨质量的影响;介绍了修磨工艺及修磨机的设备组成, 带钢研磨后党风的表面缺陷及防止措施。     

Al2O3陶瓷超声磨削的微观机理分析

对Al2O3陶瓷的超声磨削在微观机理上进行了初步探究，并根据实验数据分析了不同加工条件对加工表面质量的影响，对超声和机械磨削加工效果也进行了对比。实验表明超声应用于加工Al2O3陶瓷有助于改善表面加工质量，因此，也可用于加工类似的高硬脆材料。