钛合金薄壁件车削加工的研究

传统的钛合金车削加工因其切削速度低,刀具耐用度低,加工质量难于控制,导致加工效率低。经多次钛合金车削加工试验、优选了刀具材料,确定了刀具几何参数,依据刀具磨损情况,提供了较为合理的切削数据。解决了钛合金薄壁件加工变形问题。     

航空钛合金车削加工工艺试验研究

对α+β钛合金TC11进行车削工艺研究,采用无涂层、PVD Ti Al N涂层、金刚石涂层三种刀片在干式加工和MQL冷却状态下进行车削试验。研究不同刀具、冷却方式和加工参数对车削TC11钛合金切削力、切削温度、加工表面质量、刀具寿命和刀具磨损方式等影响规律。通过相关试验数据得出相关切削参数,为优选加工刀具提供参考。     

考虑刀具磨损的细长轴车削参数动态调整策略

为解决细长轴车削加工弯曲变形量和表面粗糙度难以控制的质量问题,以及传统优化方法受刀具磨损影响导致加工质量可靠性差的弊端,以对称车削工艺为研究基础,基于细长轴车削过程弯曲变形和表面粗糙度形成机理分析,确定影响细长轴加工质量的关键因素;经试验分析、建立预测模型和多目标优化得出刀具未磨损条件下的最优车削参数;通过探究同一组车削参数条件下不同刀具磨损深度对加工结果的影响规律,提出基于刀具磨损深度的最优车削参数动态调整策略。经实际生产验证,最优车削参数动态调整策略不仅可以实现不同刀具磨损深度下弯曲变形量和表面粗糙度的精准控制,还可以提升生产效率、稳定生产节拍和降低生产成本。     

硬车削滚动轴承套圈的试验研究

针对滚动轴承套圈硬车削加工过程中表面质量存在的问题,对硬车削过程中切削用量和刀具参数对表面粗糙度的影响进行了研究,采用CBN刀具进行了6205滚动轴承套圈的硬车削加工试验,将进给量、切削速度、切削深度和刀尖圆弧半径作为试验因子,通过正交试验分析了它们对零件加工后表面粗糙度的影响规律,并归纳出了该试验范围内的最佳切削用量和刀具参数组合。研究结果表明,进给量对表面粗糙度的影响最大,刀尖圆弧半径对表面粗糙度的影响次之,切削速度对表面粗糙度的有一定影响,切削深度对表面粗糙度的影响非常小。     

粉末冶金烧结钢切削加工试验研究

采用硬质合金刀具、陶瓷刀具和PCBN刀具对粉末冶金Fe-1．0Ni-0．5Mo-0．5Cr低合金烧结钢进行车削试验。研究了切削速度、进给量对加工表面粗糙度的影响。结果表明,车削Fe-1．ONi-0．5Mo-0．5Cr低合金烧结钢所选的PCBN刀具的刀具耐用度以及加工表面粗糙度优于陶瓷刀具和硬质合金类刀具,但从加工效率和经济性方面考虑,陶瓷刀具是半精加工和精加工的首选。     

低硬度陶瓷的车削试验研究

通过对刀具几何参数，切削用量的优化选择进行耐用度试验，认为用硬质合金刀具，可以实现车削加工低硬度陶瓷（ＨＶ２３０￣５７０）材料，文中给出了刀具最佳几何角度，指出切削低硬度陶瓷时，切削速度对耐用度影响最大，切削深度次之，进给量最小，与切削金属时不同。     

氟金云母可加工陶瓷车削中的刀具磨损

通过对氟金云母可加工陶瓷进行车削加工试验,分析了其刀具磨损过程,通过电镜观察讨论了刀具磨损形态,以单因素实验法考查了刀具材料、冷却条件等因素对刀具磨损的影响。     

PCD刀具车削氧化锆陶瓷表面粗糙度及刀具磨损试验研究

为验证氧化锆陶瓷在大参数下的可加工性,使用PCD刀具对完全烧结的氧化锆陶瓷进行单因素硬态干式车削试验,以表面粗糙度为评价指标,研究了刀尖圆角半径、切削深度对已加工表面粗糙度的影响,通过对刀具磨损形貌和切屑进行观察,结合能谱图分析了刀具磨损形态、材料去除方式以及刀具的主要磨损机理。试验结果表明：在两组较大切削深度下,随着切削深度和刀尖圆角半径的增加,表面粗糙度总体呈现增大趋势;刀具磨损集中在刀尖处,主要形式是脆性剥落和黏结磨损。     

采用试验设计法优化铝合金超精密车削加工参数

采用试验设计法对5083铝合金超精密车削的加工参数进行研究和优化,通过部分析因设计和响应曲面方法确认显著影响铝合金超精密车削的加工参数,应用JMP数据统计分析软件对试验结果进行回归分析。试验结果表明,在使用天然金刚石刀具的条件下,影响5083铝合金超精密车削的主要加工参数是进给量和切削速度。当进给量为0.06 mm/r、切削速度为1 010 m/min时,超精密车削加工得到的铝合金表面粗糙度Ra仅为0.03μm,刀具的有效加工距离为34 km,使用寿命明显提升。     

可转位硬质合金车刀车削45钢车削力预报

采用金属成形有限元分析软件Deform3D建立了可转位硬质合金车刀车削45钢的三维斜角切削有限元模型,利用该模型进行了切削加工模拟,得到切削力的数值并给出了切削力随时间的变化曲线.通过设置不同的切削参数,对不同参数下的车削力进行比较,分析各个切削参数对车削力的影响规律,为研究刀具的切削性能提供有用的数据.     

Some studies on hard turning of AISI 4340 steel using multilayer coated carbide tool

Hard turning with multilayer coated carbide tool has several benefits over grinding process such as, reduction of processing costs, increased productivities and improved material properties. The objective was to establish a correlation between cutting parameters such as cutting speed, feed rate and depth of cut with machining force, power, specific cutting force, tool wear and surface roughness on work piece. In the present study, performance of multilayer hard coatings (TiC/TiCN/Al₂O₃) on cemented carbide substrate using chemical vapor deposition (CVD) for machining of hardened AISI 4340 steel was evaluated. An attempt has been made to analyze the effects of process parameters on machinability aspects using Taguchi technique. Response surface plots are generated for the study of interaction effects of cutting conditions on machinability factors. The correlations were established by multiple linear regression models. The linear regression models were validated using confirmation tests. The analysis of the result revealed that, the optimal combination of low feed rate and low depth of cut with high cutting speed is beneficial for reducing machining force. Higher values of feed rates are necessary to minimize the specific cutting force. The machining power and cutting tool wear increases almost linearly with increase in cutting speed and feed rate. The combination of low feed rate and high cutting speed is necessary for minimizing the surface roughness. Abrasion was the principle wear mechanism observed at all the cutting conditions.     

车削高温合金GH2132时切削力和表面粗糙度的建模与试验分析

对高温合金GH2132进行了外圆车削试验,测量了切削过程中的切削力和已加工表面粗糙度。利用最小二乘法对试验数据进行了回归分析,建立了切削力和表面粗糙度的经验模型,得出了切削参数对切削力和粗糙度的影响规律,为优化切削参数、研究刀片磨损机理提供了参考数据。     

考虑极限切削宽度的45钢切削力仿真分析

以高速车削45钢为研究对象,针对高速车削颤振问题,通过绘制稳定性叶瓣图得到无颤切削参数。利用Third Wave AdvantEdge有限元分析软件,基于无颤切削参数设计正交试验,运用极差分析法得到切削用量对各切削力的影响主次顺序和最优组合。根据仿真试验结果,建立了车削力预测模型并检验了回归模型的可靠性。通过单因素试验法分析研究了各切削参数对车削力的影响规律,从减小车削力和提高高速车削加工稳定性方面出发,在所选参数范围内得出了高速车削45钢时的最优参数组合为:v=1200m/min,f=0.05mm/r,ap=0.2mm。     

Performance of coated and uncoated mixed ceramic tools in hard turning process

The present contribution deals with the study of the effects of cutting speed, feed rate and depth of cut on the performance of machining which traditionally named “machinability”. The focus is made on the effect of the pre-cited cutting parameters on the evolution of surface roughness and cutting force components during hard turning of AISI D3 cold work tool steel with CC6050 and CC650 ceramic inserts. Also, for both ceramics a comparison of their wear evolution with time and its impact on the surface equality was proposed. The planning of experiments was based on Taguchi’s L₁₆ orthogonal array. The analysis of variance (ANOVA), the signal-to-noise ratio and response surface methodology (RSM) were adopted. Consequently, the validity of proposed linear regression model was checked and the most important parameter affecting the surface roughness and cutting force components were determined. Furthermore, in order to determine the levels of the cutting regime that lead to minimum surface roughness and minimum machining force the relationship between cutting factors was analyzed. The results revealed that the surface quality obtained with the coated CC6050 ceramic insert is 1.6 times better than the one obtained with uncoated CC650 ceramic insert. However, the uncoated ceramic insert was useful in reducing the machining force.     

微细轴切削加工特性分析

分别采用传统的车削方法和先进的车铣方法进行微细轴的切削加工试验,从切削方式、切削速度、切削力等9个方面对两种切削方法进行了比较。试验结果表明,车铣技术更适合于微细轴类零件的加工,它在改善微小型零件的切削状态、实现高速切削、降低切削力、延长刀具寿命、保证零件加工质量、提高加工效率等方面都具有明显优势,只要合理匹配车削主轴与铣削主轴的转速比,同时合理辅以其他切削用量,就可以加工出理想的微小型零件。     

High-Speed Machining of Malleable Cast Iron by Various Cutting Tools Coated by Physical Vapor Deposition

The coating material of a tool directly affects the efficiency and cost of machining malleable cast iron.However,the machining adaptability of various coating materials to malleable cast iron has been insufficiently researched.In this paper,turning tests were conducted on cemented carbide tools with different coatings(a thick TiN/TiAlN coating,a thin TiN/TiAlN coating,and a nanocomposite(nc)TiAlSiN coating).All coatings were applied by physical vapor deposi-tion.In a comparative study of chip morphology,cutting force,cutting temperature,specific cutting energy,tool wear,and surface roughness,this study analyzed the cutting characteristics of the tools coated with various materials,and established the relationship between the cutting parameters and machining objectives.The results showed that in malleable cast iron machining,the coating material significantly affects the cutting performance of the tool.Among the three tools,the nc-TiAlSiN-coated carbide tool achieved the minimum cutting force,the lowest cutting tempera-ture,least tool wear,longest tool life,and best surface quality.Moreover,in comparisons between cemented-carbide and compacted-graphite cast iron machined under the same conditions,the wear mechanism of the coated tools was found to depend on the cast iron being machined.Therefore,the performance requirements of a tool depend on multiple factors,and selecting an appropriately coated tool for a particular cast iron material is essential.     

基于Deform 3D的金属车削过程仿真

基于材料变形的弹塑性理论、热力耦合理论以及Usui磨损模型,采用有限元仿真技术,利用三维仿真软件Deform对车削过程进行仿真,得出了在不同切削用量下切削力的变化规律、切削过程中刀具中切削应力的分布情况以及刀具表面切削热的分布情况。仿真结果为生产实践中切削用量的优化选择提供理论依据。     

SiCp/Al复合材料薄壁件车削力的仿真研究

应用有限元分析软件ABAQUS对Si Cp/Al复合材料薄壁件车削力进行了仿真研究,得到了切削用量对切削力的影响规律,并结合文献的实验成果对相应规律进行了分析。仿真结果表明:在Si Cp/Al复合材料薄壁件车削过程中,随切削速度的增大,三向切削分力(轴向力Fx、径向力Fy、切向力Fz)均增大,但径向力Fy增幅很小;随进给量的增大,三向切削分力都有增大的趋势;随背吃刀量的增大,三向切削分力均显著增大;背吃刀量是影响切削力的主要因素。     

Surface roughness and cutting force prediction in MQL and wet turning process of AISI 1045 using design of experiments

This paper presents an investigation into the MQL (minimum quantity lubrication) and wet turning processes of AISI 1045 work material with the objective of suggesting the experimental model in order to predict the cutting force and surface roughness, to select the optimal cutting parameters, and to analyze the effects of cutting parameters on machinability. Fractional factorial design and central composite design were used for the experiment plan. Cutting force and surface roughness according to cutting parameters were measured through the external cylindrical turning based on the experiment plan. The measured data were analyzed by regression analysis and verification experiments were conducted to confirm the results. From the experimental results and regression analysis, this research project suggested the experimental equations, proposed the optimal cutting parameters, and analyzed the effects of cutting parameters on surface roughness and cutting force in the MQL and wet turning processes.     

FEM SIMULATION AND EXPERIMENTAL RESEARCH ON THE SHEET BLANKING

0 INTRODUCTIONBlanking is one of the most widely usedmetalforming processes to produce machineparts.Blanking clearance between punch and femaledie is one of the most important parameters that affectthe cutting fOrce and the cutting surface quality. Theabsolute value of clearance depends on the thickness ofthe sheet metal, its tensile and shearing strength, aswell as on the cutting speed, the type of blankingpunch and the required quality of the cuttingsurface. In steel sheet blanking, man…