PCBN刀片铣削QT450球墨铸铁的试验研究

为研究PCBN铣刀片铣削球墨铸铁的性能,采用陶瓷结合剂PCBN铣刀片(T-PCBN)和金属结合剂PCBN铣刀片(J-PCBN)进行铁素体球墨铸铁(QT450-10)铣削试验,对比研究两种铣刀片的铣削力、振动、磨损机理和使用寿命。结果表明：相同切削参数下,T-PCBN刀片的铣削力和振动小于J-PCBN铣刀片;两种刀片均存在黏结、扩散、氧化以及磨粒磨损,T-PCBN铣刀片主要的失效形式是崩刃,J-PCBN铣刀片的失效形式为磨损,直至达到磨钝标准;J-PCBN铣刀片的服役寿命远高于T-PCBN铣刀片。     

基于二维元胞自动机的铣刀片温度场算法研究

切削热是铣刀片磨损和破损产生的重要原因.对铣刀片温度场研究的传统方法是有限元法.为了实现三维复杂槽型铣刀片槽型优化中能直接利用分析得到的数据进行自组织动态设计,文中结合切削温度试验,利用元胞自动机理论对铣刀片温度场进行研究,建立了二维波形刃铣刀片温度场算法系统,得出切削中各点的温度场,为刀片槽型重构奠定基础.     

三维复杂槽型铣刀片耦合场的数值模拟

为研究三维复杂槽型铣刀片的切削性能和失效机理,运用数值模拟技术对三维复杂槽型铣刀片和平前刀面铣刀片进行了热应力场、热应力与机械应力的耦合场分析。通过有限元分析,得到了两种铣刀片的应力集中区和危险区,经与试验结果对比,证明了有限元分析结果的正确性,说明三维槽型铣刀片具有优于平前刀面铣刀片的切削性能,从而预测在铣刀片上开出合理的槽型能有效地改善切削性能。     

可转位圆形铣刀片定位稳定性研究

在加工过程中,保证圆形铣刀片定位的稳定性非常重要。由于圆形铣刀片定位结构及切削过程中的切削力是影响刀片定位稳定性的主要因素,因此本文主要针对可转位圆形铣刀片铣削加工不锈钢时的夹固稳定性进行研究,分析无限位结构圆形铣刀片在不同切削工况下刀片夹固稳定性,并对提出的两种优化方案进行试验验证。研究结果表明：在大切削深度或大进给参数条件下,无限位结构设计的圆形铣刀片会发生旋转,且转动幅度随切削时间的延长而增大;优化后的限位结构可有效阻止刀片转动,且底部八边形斜面限位结构较底部凹槽限位结构防转性能显著。     

耐热钢加工刀具粘结破损数学模型的研究

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数学模型的研究.首先,进行铣刀片切削温度实验,对铣刀片粘结破损机理进行分析;其次,通过实验揭示不同铣刀片粘结破损失效形式的差异;在粘结破损实验的基础上,建立铣削温度与前刀面最大粘结破损深度之间的数学模型,分析铣削温度对刀具粘结破损的影响规律.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打下理论与试验基础.     

三维复杂槽型铣刀片铣削温度场的计算机模拟

为研究三维复杂槽型铣刀片切削温度分布，在分析测温试验结果的基础上，依据传热学理论建立了数学模型，用Visual C 编制出刀具温度场计算的程序，可以得出三种不同刀片在每一种切削条件下切削不同工件材料的温度分布曲线图，为进一步研究三维复杂槽型铣刀片的切削机理和重构铣刀片槽型提供了依据。     

可转位波形刃铣刀片的铣削力试验研究

研究了可转位波形刃铣刀片的铣削机理,在相同条件下分别采用波形刃铣刀片和直线刃铣刀片对45钢进行了铣削试验。试验发现:波形刃铣刀片的铣削力比直线刃铣刀片低10%-20%。随后,采用正交试验研究切削参数对波形刃铣刀片铣削力的影响规律,利用线性回归法得到铣削力经验公式,通过极差分析法得出各试验参数对铣削力的影响程度,即每齿进给量对波形刃铣刀片铣削力的影响最大,其次为轴向切深和径向切深,最后是铣削速度,得出铣削力最小时所对应的切削参数,为波形刃铣刀片的高效使用提供了依据。     

通用镶片铣刀的力学和动力学模型(编译)

在机械加工中,广泛使用镶片铣刀。刀片的几何形状和在刀体上的分布非常重要。为了预断铣削时的切削、振动、表面粗糙度和稳定性。介绍镶片铣刀广义数学模型。在该文中。刀刃几何被每一刀片的局部坐标系所定义,并用来预断沿切削区的切削厚度分布。每一刀片安装在刀体上。用刀片中心相关于刀体中心的坐标数学说明。用求解每一刀刃点切削的力学和动力学,并在整个切削区积分,它可以显示出任何镶片铣刀预断的铣削过程。并用试验加以证实。     

TiAlN涂层硬质合金可转位刀具快速铣削钛合金刀片磨损研究

快速铣是一种新兴的粗加工方法,研究它的刀具磨损机理对提高刀具寿命和加工效率有着重要的作用。采用硬质合金快速铣刀片在工件上进行了钛合金TC17铣削实验,研究了不同切削参数对切削力的影响,采用多元线性回归建立了切削力数学预测模型,分析了各铣削参数对切削力的影响规律,通过对后刀面的检测,分析了刀具磨损形貌和磨损机理。结果表明:每齿进给量、切削深度对切削力的大小影响显著,切削宽度和主轴转速影响很小,在试验参数范围内,选用切削参数组合为:f_z=0.8 mm/z、a_p=0.5 mm、a_e=20 mm、s=600 r/min进行可转位刀片的磨损试验,快速铣可转位刀片的主要磨损形貌为后刀面磨损、材料剥落,后刀面主要磨损机理为黏结磨损,同时会产生一定程度的扩散磨损。     

高速切削时数控刀片的磨损

本文主要阐述高速切削时对数控刀片的要求,分析高速切削时数控刀片的磨损机理和磨损形式。在高速切削下,根据不同的材质、加工方法和加工要求确定合理的数控刀片磨损寿命。     

模具钢高速切削表面粗糙度的试验研究

用硬质合金刀具对NAK80模具钢进行了高速精密切削试验,研究了切削条件、切削用量对加工表面粗糙度的影响。切削试验结果表明:提高切削速度与减小进给量有利于改善模具钢工件的加工表面质量;当切削速度超过某一范围后,随着切削速度的进一步提高,加工表面粗糙度的降低并不明显。     

Al_2O_3-TiC复相陶瓷刀具干切削高强度钢40CrNiMoA的试验研究

用Al2O3-TiC复相陶瓷刀具对高强度钢40CrNiMoA进行了干车削试验,研究分析了精加工条件下不同切削用量对切削力、工件表面质量以及切屑形态和刀具磨损的影响。结果表明用Al2O3-TiC复相陶瓷刀具在较高速度下干车削40CrNiMoA时可获得良好的表面加工质量,并且刀具磨损量较小,可满足40CrNiMoA精加工的要求。     

Measuring procedures of cutting edge preparation when hard turning with coated ceramics tool inserts

In this paper, the authors introduce the methodology of combined studies on cutting edge preparation and tool performance testing. Five main fields of research on cutting edge preparation are identified in this study of cutting edge preparation while cutting edge microgeometry consists of data associated with tool edge and rake face. Uncoated and TiN coated mixed oxide ceramics inserts have been tested concerning their microgeometry and wear resistance and there is presented a sequence of measuring to identify cutting edge preparation and properties of coating. Authors propose the sequence which considers cutting edge preparation as a factor controlling performance of cutting edge in hard turning operations. Four steps in the sequence of performance testing include measurements with effects of wear criterion and machining time. Measured results show that combined effects of both preparation and coating reduce considerably friction forces in scratch tests and there is very negligible change of microhardness of uncoated and coated ceramics. Relationships between cutting edge microgeometry and acceptable machined surface roughness which results from the sequence in tool performance testing have been identified. Finally, tool performance indices are based on units which characterize machined surface roughness, tool edge wear and forces when hard turning.     

自乳化酯在全合成切削液中的性能研究

为探讨自乳化酯作为全合成切削液主润滑剂的可能性,以聚醚、四聚蓖麻油酸酯、自乳化酯为润滑剂调配了不同的合成切削液;采用四球抗磨试验机以及攻丝扭矩试验机、液体循环泡沫试验机,考察3种润滑剂在全合成切削液中的润滑性能、抗磨性能及抗泡性能.结果 表明:自乳化酯能有效提高全合成切削液的润滑性能和抗磨性能,其润滑性能及抗磨性能与四...     

切削用量对铣削非标内螺纹刀具磨损的影响

与传统螺纹加工方法相比,铣削螺纹不仅具有较高的加工精度和加工效率,而且不受螺纹结构的制约,可较为自由地选取合理的加工参数。应用DEFORM-3D软件对铣削非标内螺纹刀具磨损进行仿真,运用正交仿真试验研究切削速度、最大切削厚度和径向切削深度等切削用量对刀具磨损的影响,并对加工参数进行了优化。结果表明:切削刃圆角处刀具磨损最严重,在研究范围内,径向切削深度对刀具磨损的影响最大。     

麻花钻磨损特性的研究

通过对调质合金结构钢的大量钻削试验,研究了麻花钻磨损区的图形特征和磨损机理以及钻头失效与磨损图形参数、钻头切削寿命与钻削速度的关系。结果表明,麻花钻的磨损具有非线性特征,钻头转角和主刀刃及横刃区有两个显著不同的磨损区,随钻削速度的提高,这两个磨损区的特征差异及磨损带宽度之比明显增大。在钻削速度较低、钻头失效时,两个磨损区为较均衡的磨粒磨损和粘结磨损;钻削速度较高时,转角区剧烈的粘结磨损和氧化磨损使钻头加快失效,而主刀刃及横刃上的磨损却很小。受此影响,麻花钻的磨钝标准、耐用度问题较为复杂,钻头的寿命（Ｔ）－速度（Ｖ）曲线的泰勒特性范围很窄。     

Wear behaviour of alumina based ceramic cutting tools on machining steels

The advanced ceramic cutting tools have very good wear resistance, high refractoriness, good mechanical strength and hot hardness. Alumina based ceramic cutting tools have very high abrasion resistance and hot hardness. Chemically they are more stable than high-speed steels and carbides, thus having less tendency to adhere to metals during machining and less tendency to form built-up edge. This results in good surface finish and dimensional accuracy in machining steels. In this paper wear behaviour of alumina based ceramic cutting tools is investigated. The machining tests were conducted using SiC whisker reinforced alumina ceramic cutting tool and Ti[C,N] mixed alumina ceramic cutting tool on martensitic stainless steel-grade 410 and EN 24 steel work pieces. Flank wear in Ti[C,N] mixed alumina ceramic cutting tool is lower than that of the SiC whisker reinforced alumina cutting tool. SiC whisker reinforced alumina cutting tool exhibits poor crater wear resistance while machining. Notch wear in SiC whisker reinforced alumina cutting tool is lower than that of the Ti[C,N] mixed alumina ceramic cutting tool. The flank wear, crater wear and notch wear are higher on machining martensitic stainless steel than on machining hardened steel. In summary Ti[C,N] mixed alumina cutting tool performs better than SiC whisker reinforced alumina cutting tool on machining martensitic stainless steel.     

TiCN涂层硬质合金刀具铣削性能研究

采用Kistler三向压电铣削测力仪测试了刀具切削45钢过程中的切削力,利用超景深显微镜、扫描电镜和能谱仪观察分析刀具切削后的磨痕宽度、形貌和成分,获得了未涂层刀具HSS、TiN和TiCN涂层刀具的切削时间与磨痕宽度关系图,探讨了刀具的切削失效机理。采用XRD分析了涂层刀具铣削前的相结构,结果表明:TiN与TiCN涂层均表现为fcc-TiN相结构,TiCN具有明显的(111)择优取向,TiN择优取向不明显。切削试验表明:在磨痕宽度达到0.3mm时,TiCN涂层刀具的切削时间比TiN涂层刀具切削时间约长2.5倍,同时整个切削过程中TiCN比TiN具有更低的切削力。这可能是因为TiCN涂层比TiN涂层具有更高的硬度和耐磨性,并且切削过程中TiCN涂层中固溶的C能析出至晶界处,起到润滑作用,降低刀具与工件材料之间的摩擦,减小切削力,延长刀具使用寿命。SEM和EDS分析表明:TiN涂层刀具磨损失效机理为磨料磨损和粘着磨损,而TiCN涂层刀具失效以磨料磨损为主。     

HIGH SPEED MILLING OF GRAPHITE ELECTRODE WITH ENDMILL OF SMALL DIAMETER

Graphite becomes the prevailing electrode material in electrical discharging machining (EDM)currently.Orthogonal cutting experiments are carried out to study the characteristics of graph- ite chip formation process.High speed milling experiments are conducted to study tool wear and cutting forces.The results show that depth of cut has great influence on graphite chip formation.The removal process of graphite in high speed milling is the mutual result of cutting and grinding process. Graphite is prone to cause severe abrasion wear to coated carbide endmills due to its high abrasive- ness nature.The major patterns of tool wear are flank wear,rake wear,micro-chipping and breakage. Cutting forces can be reduced by adoption of higher cutting speed,moderate feed per tooth,smaller radial and axial depths of cut,and up cutting.