三维复杂槽型铣刀片粘结破损实验与槽型优选的研究

针对哈尔滨理工大学开发的三维复杂槽型波形刃铣刀片和平前刀面铣刀片,通过对耐热钢的面铣加工进行刀片粘结破损实验及槽型优选研究。首先,进行铣刀片三维温度场有限元分析,预测出波形刃铣刀片的抗粘结破损性能优良;其次,通过对温度场的模糊综合评判,预测了波形刃铣刀片的优越性能;最后,通过对难加工材料3Cr-1Mo-1/4V钢的面铣加工的实验研究,揭示了刀具粘结破损的实质,建立了铣削温度与前刀面最大粘结破损深度之间的数学模型,分析了铣削温度对刀具粘结破损的影响规律,并证明了波形刃铣刀片切削性能的优越性。     

加工碳素结构钢的三维复杂槽型铣刀片冲击破损实验研究

文中针对哈尔滨理工大学开发的三维复杂槽型波形刃铣刀片和平前刀面铣刀片,通过对碳素结构45钢的面铣加工进行了刀片冲击破损的实验研究。首先进行铣刀片三维应力场有限元分析及模糊综合评判,预测出波形刃铣刀片的抗冲击破损性能优良：其次,通过试验揭示不同铣刀片冲击破损失效形式的差异;通过大量、系统的冲击破损试验,建立冲击破损寿命累积分布函数数学模型,证明波形刃铣刀片的抗冲击破损性能优良。上述研究成果为解决自动化生产中刀具破损这一关键技术问题及槽型优选技术的研究提供了理论与试验基础。     

波形刃铣刀片温度场的试验研究

利用大型软件ANSYS对波形刃铣刀片及平前刀面铣刀片进行了有限元分析,并应用模糊数学理论对其温度场进行了模糊综合评判,预测了三维复杂槽型波形刃铣刀片的优越性能;通过对难加工材料3Cr-1Mo-1/4V钢的铣削试验,对采集数据应用Matlab软件进行处理,得到前刀面刀—屑接触区平均温度与时间关系的试验方程,对比分析也证明了波形刃铣刀片的优越性。     

不同槽型铣刀片的切削温度场分析

对三种槽型的铣刀片进行了切削温度试验 ,根据切削条件建立了温度场有限元分析的边界条件 ,并对不同槽型铣刀片的三维温度场进行了有限元分析 ,为铣刀片槽型的设计和优选提供了参考依据     

波形刃铣刀片的开发及其铣削力数学模型

在研究铣削机理和试验研究的基础上,开发了一种新型三维槽型铣刀片─—波形刃铣刀片,并在直线刃铣刀片(含大前角铣刀片)铣削力模型的基础上,建立了波形刃铣刀片铣削力模型,同时编制了计算机程序进行预测,为开发设计优选铣刀片槽型提供了理论依据。     

耐热钢加工铣刀片粘结破损目标函数的研究

以哈尔滨理工大学开发的波形刃(前刀面为波形曲面)铣刀片为例,以最小粘结破损为目标,进行铣刀片槽型优化目标函数的研究。在已建立的三维复杂槽型铣刀片受热密度函数的基础上,进行铣刀片不同切削参数下的温度场有限元分析,应用模糊数学理论对温度场进行模糊综合评判,建立温度场模糊评判结果与粘结破损切削参数之间的目标函数关系,从而进行目标函数的槽型优化设计。上述研究成果为铣刀片的开发及解决自动化生产中刀具破损这一关键技术问题的研究打下理论基础。     

三维复杂槽型铣刀片切削温度与粘接破损研究

通过对难加工材料3Cr1Mo1/4V钢面铣加工的试验研究得出，在相同的切削条件下，波形刃铣刀片和大前角铣刀片的切削温度明显低于平前刀面铣刀片，抗粘结破损的能力较高：并证明切削速度越低、进给量越大，刀具的粘接破损越严重，最后给出了切削温度与前刀面最大粘结破损深度之间的重化关系，定性分析了切削温度对刀具粘结破损的影响规律。     

波形刃铣刀片温度场边界条件的研究

通过传热学、流体力学、切削理论的综合运用对波形刃铣刀片温度场边界条件进行了研究。采用相似原理对面铣加工过程中波形刃铣刀片表面的对流换热系数进行了分析 ,得出了对应的计算公式 ;结合铣削温度试验 ,推导出了前刀面刀—屑接触面输入的热流密度的函数表达式。给出了波形刃铣刀片温度场有限元分析的边界条件 ,为进一步研究铣刀片的粘结破损和槽型优选提供了理论依据。     

基于遗传算法的铣刀片三维复杂槽型重构技术

为了获得切削性能更优良的可转位铣刀片槽型,从而改善铣刀片的温度场和应力场,进行了三维复杂槽型铣刀片的测温试验、三维温度场分析及其模糊综合评判。基于遗传算法,提出了以受热密度函数为目标函数,以温度场模糊综合评判为驱动的铣刀片三维复杂槽型的重构算法,获得了新的波形槽型。实例验证表明,新槽型较重构前的槽型在温度场方面具有更好的性能。利用该方法同样可以构造拟合其他类型三维复杂槽型。     

基于应力场分析的铣刀片冲击破损目标函数研究

以哈尔滨理工大学开发的波形刃(前刀面为波形曲面)铣刀片为例,以最小冲击破损为目标,进行铣刀片槽型优化目标函数的研究。在已建立的三维复杂槽型铣刀片受力密度函数的基础上,进行铣刀片不同切削参数下的应力场有限元分析,应用模糊数学理论对应力场进行模糊综合评判,建立应力场模糊评判结果与冲击破损切削参数之间的目标函数关系,从而进行目标函数的槽型优化设计。本研究为铣刀片的开发及解决自动化生产中刀具破损这一关键技术问题打下理论基础。     

三维复杂槽型铣刀片铣削温度试验研究

基于人工热电偶法及自行设计的转轴信号变送器,建立了铣削温度试验系统;通过时刻转换、周期转换、热电偶冷端温度补偿、温度转换和曲线拟合等数据处理手段,得到了不同槽型铣刀片各个测温点的温度以及前刀面刀—屑接触区的平均温度与时间之间的试验方程式;编制了实验数据处理应用软件。试验结果证明:测试系统性能良好;并且波形刃铣刀片切削性能优于平前刀面铣刀片。研究成果为受热密度函数与温度场数学模型的建立打下基础。     

Study on a new turning method to simulate orthogonal cutting and to verify an edge breakout model

In order to verify an edge breakout predicting model in orthogonal cutting, which was proposed by the author’s previous work, orthogonal machining experiments must be conducted. A CNC lathe was utilized to carry out simulated orthogonal cuttings. The workpiece, made of aluminum alloy Al 6061-T6, is a cylindrical bar with square threads and axial/radial grooves. Threading and grooving inserts with a flat cutting edge were chosen as the cutting tools. The experimental data were used to verify the previously developed edge breakout model. The tests showed excellent agreement with the model predictions.     

基于密度函数的三维复杂槽型铣刀片物理场分析

以哈尔滨理工大学开发的波形刃(前刀面为波形曲面)铣刀片为例,在铣削力数学模型基础上,通过铣削力试验以及切屑与前刀面接触面积试验,建立了三维复杂槽型铣刀片前刀面的受力密度函数;基于该函数,对波形刃铣刀片进行了应力场分析。在铣削温度数学模型基础上,运用传热学理论,建立了波形刃铣刀片表面受热密度函数;基于该函数,对波形刃铣刀片进行了温度场分析。这些研究结果可为槽型优选技术的研究打下理论基础。     

复杂槽型铣刀片三维温度场分析及其模糊综合评价

建立了三维复杂槽型铣刀片的参数化模型,提出并建立了刀具表面受热密度函数,根据受热密度函数确定了边界条件,对铣刀片的温度场进行了有限元分析;运用模糊数学理论对铣刀片温度场进行了模糊综合评判,以确定其优劣,为铣刀片三维复杂槽型的重构提供依据。     

三维复杂槽型铣刀片切入过程应力状态的研究

以哈尔滨理工大学开发的波形刃铣刀片（前刀面为波形曲面）为例,针对刀具切入破损问题,确定了切入瞬问冲击载荷的分布与作用力方向;应用弹性力学方法,对三维复杂槽型铣刀片进行了应力状态分析,并讨论了其应力分布规律。理论分析结果与铣刀片应力场分析结果吻合较好。研究结果为解决自动化生产中刀具破损问题及槽型优化技术研究打下了理论基础。     

三维复杂槽型铣刀片铣削力的数学模型

在直线刃铣刀片模型的基础上，利用曲线积分原理，建立了波形刃铣刀片铣削国工民该方法可以适用于任意曲线刃的三维复杂槽型的情况。根据由述结果，文章还对平刀面铣刀片、大前角铣刀片及波形刃铣刀片的铣削试验验证，共预报结果与试验结果的变化趋势符合较好，可用于铣刀片的槽形开发优选。     

基于BP神经网络的波形刃铣刀片模糊综合评判系统

针对波形刃铣刀片耦合场的非稳态特性,基于铣削温度和铣削力试验以及有限元分析,利用BP神经网络LM算法预测了铣刀片温度场和应力场;运用模糊数学理论,根据加工要求和专家分析,用VC++开发了波形刃铣刀片模糊综合评判系统。该系统可对多因素作用下的铣刀片温度场、应力场和耦合场的优劣进行评判,为铣刀片三维复杂槽型的重构提供依据。     

A Cutting Force Model for a Waved-Edge End Milling Cutter

This paper presents a model for predicting the cutting forces for waved-edge milling cutters that are widely used in rough machining. The development of the model is based on the analysis of the complicated cutting edge of waved-edge cutter. According to the existing local cutting force model and from the relationship of local cutting force and chip load, local cutting force can be derived. Then the model is obtained by dividing the cutter into a number of differential elements in the axial direction and summarising the resultant cutting force produced by each differential cutter disc engaged in the cut. A numerical algorithm is introduced for the calculation of total force and the calibration of the relevant parameters in the model. A series of experiments under different cutting conditions are conducted to confirm the validity of the developed model. The agreement between the experimental and simulative results is satisfactory, which shows that the model is effective for cutting force prediction in end milling with waved-edge cutters. ID="A1"Correspondance and offprint requests to: Prof. L. Zheng, Institute of Manufacturing Engineering, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing, 100084, P. R. China. E-mail: lzheng@tsinghua.edu.cn     

Performance of the self-lubricating textured tools in dry cutting of Ti-6Al-4V

Surface textures were made using laser on the rake or flank face of the cemented carbide (WC/Co) inserts. Molybdenum disulfide solid lubricants were filled into the textured grooves to form self-lubricating textured tools. Dry cutting tests on Ti-6Al-4V were carried out with these self-lubricating textured tools and conventional tool. The machining performance was assessed in terms of the cutting forces, cutting temperature, chip thickness ratio, friction coefficient at the tool–chip interface, and tool wear. Results show that the cutting forces and cutting temperature of the self-lubricating textured tools were reduced compared with that of the conventional tool. The application of the self-lubricating textured tool with elliptical grooves on its rake face can reduce the tool–chip friction coefficient and the chip thickness ratio. The tool life of the textured tools is improved compared with that of the conventional tool. The effectiveness of the self-lubricating textured tools in improving cutting performance is related to the cutting parameter.     

Experimental investigations on machinability aspects in finish hard turning of AISI 4340 steel using uncoated and multilayer coated carbide inserts

The present work deals with some machinability studies on flank wear, surface roughness, chip morphology and cutting forces in finish hard turning of AISI 4340 steel using uncoated and multilayer TiN and ZrCN coated carbide inserts at higher cutting speed range. The process has also been justified economically for its effective application in hard turning. Experimental results revealed that multilayer TiN/TiCN/Al₂O₃/TiN coated insert performed better than uncoated and TiN/TiCN/Al₂O₃/ZrCN coated carbide insert being steady growth of flank wear and surface roughness. The tool life for TiN and ZrCN coated carbide inserts was found to be approximately 19 min and 8 min at the extreme cutting conditions tested. Uncoated carbide insert used to cut hardened steel fractured prematurely. Abrasion, chipping and catastrophic failure are the principal wear mechanisms observed during machining. The turning forces (cutting force, thrust force and feed force) are observed to be lower using multilayer coated carbide insert in hard turning compared to uncoated carbide insert. From 1st and 2nd order regression model, 2nd order model explains about 98.3% and 86.3% of the variability of responses (flank wear and surface roughness) in predicting new observations compared to 1st order model and indicates the better fitting of the model with the data for multilayer TiN coated carbide insert. For ZrCN coated carbide insert, 2nd order flank wear model fits well compared to surface roughness model as observed from ANOVA study. The savings in machining costs using multilayer TiN coated insert is 93.4% compared to uncoated carbide and 40% to ZrCN coated carbide inserts respectively in hard machining taking flank wear criteria of 0.3 mm. This shows the economical feasibility of utilizing multilayer TiN coated carbide insert in finish hard turning.