An experimental study of tool wear and cutting force variation in the end milling of Inconel 718 with coated carbide inserts

Inconel 718 is a difficult-to-cut nickel-based superalloy commonly used in aerospace industry. This paper presents an experimental study of the tool wear propagation and cutting force variations in the end milling of Inconel 718 with coated carbide inserts. The experimental results showed that significant flank wear was the predominant failure mode affecting the tool life. The tool flank wear propagation in the up milling operations was more rapid than that in the down milling operations. The cutting force variation along with the tool wear propagation was also analysed. While the thermal effects could be a significant cause for the peak force variation within a single cutting pass, the tool wear propagation was believed to be responsible for the gradual increase of the mean peak force in successive cutting passes.     

Al2O3/Cu复合材料的内氧化制备及性能研究

采用高能球磨制备出亚稳态的Cu-1%Al（质量分数）合金粉,再将Cu2O粉与其一起进行高能球磨,然后将复合粉末压坯在N2保护炉中同时进行氧化和烧结,制备出Al2O3/Cu复合材料。分析了分别采用湿法球磨和干法球磨时的合金化效果,讨论了模压压力对材料性能的影响。结果表明,对于Cu-Al混合粉来说,采用湿法球磨容易产生分层,采用干法球磨具有良好的合金化效果;在本试验条件下,750MPa为最佳的模压压力,但烧结后材料的电导率还是偏低,因此有必要进行后续的处理来进一步提高材料的性能。     

电火花铣削中电极损耗及补偿的几何描述方法

提出了电火花铣削加工的基于数学模型的电极分解加工补偿法，即通过将电火花铣削加工过程划分为两个阶段——型腔侧面轮廓加工和底面的加工，这样就简化了放电状态的检测和电极补偿运动。在分别对侧面和底面加工过程分析的基础上，建立了侧面轮廓和底面加工的电极损耗和补偿的数学模型，为电极自动在线补偿提供了理论基础。     

基于VERICUT的虚拟龙门加工中心建模和仿真关键技术研究

为减少零部件试切,检验数控工艺合理性,构建了虚拟龙门加工中心。研究了龙门加工中心运动,阐述了侧面铣头运动由旋转中心和换刀点控制,提出了虚拟机床侧面铣削运动构建方法,可实现各角度侧面铣。搭建了虚拟加工环境,通过零件仿真加工,完成了零件顶面及4个侧面的铣削加工,验证了数控代码的正确性,检验了数控工艺合理性,减少了零件试切,缩短了开发周期,仿真结果表明虚拟龙门加工中心的正确性。     

双零铝箔分切缠卷时螺纹的产生与预防

双零铝箔分切缠卷时产生的螺纹是铝箔生产过程中严重的质量缺陷，此缺陷的产生主要与轧制工序来料板形、分切所用管芯质量、分切设备的稳定性及操作者的技术水平等有关。分析了铝箔分切工序螺纹产生的原因，采取适当的控制方法，防止分切时产生的螺纹。     

基于遗传算法优化铣削用量的数控加工仿真系统的研究

遗传算法是一种模拟生物界自然选择和自然遗传机制的自适应搜索和优化方法,在搜索优化问题的全局或全局附近的最优解上具有良好的优势条件.文章建立了基于遗传算法思想的铣削用量多目标智能优化的数学模型及其数控加工动态仿真系统,运用遗传优化方法对铣削加工实例进行优化,并在数控加工动态仿真系统上验证了铣削用量多目标智能优化的数学模型的正确性和实用性.     

高速铣削钛合金TC4切削力试验研究及切削参数优化

采用正交试验研究了高速铣削钛合金TC4粗加工阶段时切削参数对切削力的影响规律，并以Y向切削力最小和材料去除率最大为优化目标，利用MATLAB基于Pareto遗传算法优化高速铣削TC4的切削参数，结合Pareto最前沿给出了优化后的切削参数最优解集。     

Simplified and efficient calibration of a mechanistic cutting force model for ball-end milling

Accurate evaluation of the empirical coefficients of a mechanistic cutting force model is critical to the reliability of the predicted cutting forces. This paper presents a simplified and efficient method to determine the cutting force coefficients of a ball-end milling model. The unique feature of this new method is that only a single half-slot cut is to be performed to calibrate the empirical force coefficients that are valid over a wide range of cutting conditions. The instantaneous cutting forces are used with the established helical cutting edge profile on the ball-end mill. The half-slot calibration cut enables successive determination of the lumped discrete values of the varying cutting mechanics parameters along the cutter axis whereas the size effect parameters are determined from the known variation of undeformed chip thickness with cutter rotation. The effectiveness of the present method in determining the cutting force coefficients has been demonstrated experimentally with a series of verification test cuts.     

球磨过程中的碰撞行为分析

本文通过对行星球磨过程的分析，研究了行星球磨过程中的磨球碰撞行为，建立了球磨工艺参数与磨球运动速度。平均自由程及碰撞频率的理论关系。结果表明：随球磨转速提高，磨球运动速度和碰撞频率将增大，装料量一定时，提高球料比，磨球运动速率和平均自由程都将减小，碰撞频率增大，装料量和球料比一定时，磨球半径愈小，磨球运动的平均自由程减减小，碰撞频率增大。     

铸轧辊的改进设计

对铸轧辊辊芯的表层处理、辊芯的结构、铸轧辊的装配进行了改进设计 ,提高了铸轧辊的性能 ,延长了使用寿命