TiN和TiAlN涂层刀具铣削铝锂合金表面质量试验对比研究

目的 比较TiN和TiAlN涂层刀具加工铝锂合金的切削性能和表面质量。方法 使用硬质合金、TiN涂层和TiAlN涂层三种刀具,对2198-T8型铝锂合金进行干式铣削试验。改变切削因素的水平,比较刀具磨损、铝锂合金的表面粗糙度、切削力和切屑形态。结果 铣削铝锂合金时,刀具主要磨损为粘附磨损,TiN涂层的粘附程度最低,硬质合金次之,TiAlN涂层表面粘附最严重,切削效能最低。粘附磨损严重影响铣削成形的表面粗糙度,并使铣削力增加。铣削速度是影响工件表面粗糙度的主要因素,通过提高铣削速度可明显降低材料的粘结程度,降低表面粗糙度与铣削力,TiN涂层在铣削铝锂合金时最小表面粗糙度可达到0.5 μm以下。在相同的切削参数下,TiN涂层断屑均匀,切屑表面较为光滑,切屑塑性变形最小。硬质合金刀具产生的切屑尺寸较短,切屑表面有少量带状条纹,TiAlN涂层刀具产生的切屑发生了严重的塑性变形。结论 与TiAlN涂层和硬质合金刀具相比,TiN涂层刀具在铣削铝锂合金时的切削效能最好,可以达到最好的表面粗糙度和加工效果。     

铝硅合金ADC12高速铣削力实验研究

针对某E型发动机缸体、缸盖材料─铝硅合金ADC12,采用硬质合金四刃直柄平头立铣刀,进行了高速铣削力单因素以及正交实验。探究了高速立铣过程中,切削力在不同的切削条件下随切削参数改变而变化的规律以及产生原因。根据方差分析结果,得到各切削参数对各向切削力的影响显著性大小。在分析实验结果的基础上,指出了铝硅合金ADC12高速切削参数选取的一般原则。     

汽车轮毂用新型铝硅镁系铸造铝合金耐磨性能研究

铝硅镁系铸造铝合金在汽车工业上应用非常广泛,汽车制造中轮毂用的材料几乎都采用铝硅镁系合金。以ZL101为基体添加了Cu、Si、Mg、Mn等多种合金元素形成一种新型铝硅镁系合金,对改良合金材料及基体材料在变换载荷及润滑状况的条件下进行摩擦磨损试验,对这两种材料的耐磨性进行研究,对磨件为淬火45钢。摩擦磨损试验结果表明,在干摩擦及油润滑摩擦条件下新型铝硅镁系铸造铝合金的耐磨性和减摩性均优于对比材料ZL101合金。     

基于J-C断裂模型的镍基材料高速切削成型模拟

在高温合金高速切削成型过程中采用Johnson-Cook热弹塑性模型构建IN625材料失效本构模型,使用非线性结构力学软件ABAQUS及利用explicit算法创建了高温合金切削数值模型。引入材料剪切失效和断裂失效判据及刀-屑摩擦模型,对高速切削过程中刀具对材料成形的影响、切屑的成型和切削力进行了计算和研究。     

Sip/ZA40复合材料磨损性能研究

采用磨损试验研究了干磨擦和油润滑摩擦条件下,硅含量对含硅高铝锌基复合材料磨损性能的影响。应用扫描电子显微镜分析了复合材料磨面的形貌特征。结果表明,含硅高铝锌基复合材料的耐磨损性能优于基体合金;在油润滑条件下,硅含量越高,复合材料的耐磨性能越好;在干摩擦条件下,硅含量为4.5％复合材料的耐磨性能优于其它试验材料。含硅材料的磨损机理是微切削磨损、表面脱落和磨粒磨损的综合作用。     

铝硅合金ADC12切削仿真与试验分析

针对某汽油机缸体、缸盖材料——铝硅合金ADC12的高速切削参数的优化选择,采用其Johnson-Cook本构模型,在有限元软件ABAQUS中采用热-力耦合分析单元用硬质合金刀具对其进行二维高速切削仿真,得出该合金在不同切削参数下的切削力大小及变化规律,经过对比分析得出其最优的切削参数。然后在高速铣床上对该发动机缸体、缸盖材料进行高速铣削试验,将试验结果与仿真结果进行对比,验证了有限元切削仿真的有效性,为该缸体、缸盖进行高速铣削提供合理铣削参数的选择依据。     

切削过程的动力学模型

本文研究了刀具与工件摩擦接触并处于熔融状态时切削过程的数学模型.在此基础上,提出了互相作用摩擦副的粘结机理.     

CVD金刚石薄膜涂层刀具切削性能研究

本文采用不同涂层工艺的ＣＶＤ金刚石薄膜刀具切削高硅铝合金,观测比较刀具的磨损过程、磨损与破损形貌及工件表面粗糙度,分析ＣＶＤ金刚石薄膜刀具切削主崖裂口合金的磨损机理和失效原因。研究结果可为涂层工艺的提供了理论依据。     

PVD-TiAlN涂层硬质合金刀具高速干车削TC4合金磨损演变机理

以难切削材料TC4合金的加工刀具为研究对象,采用PVD-TiAlN硬质合金涂层刀具进行高速干车削试验,研究刀具在切削中不同磨损阶段的磨损形式演变以及磨损机理。研究表明:涂层刀具主要的失效拐点在稳定磨损阶段后期。在高速车削不同刀具磨损阶段,随切削时间的增加,刀具前刀面主要磨损形式由月牙洼逐渐变为积屑瘤、崩刃以及涂层剥落,主要磨损机理为粘结磨损、氧化磨损;刀具后刀面的磨损形式由切屑与氧化物的粘结逐渐变为积屑瘤、崩刃、沟痕、涂层剥落以及高温烧蚀,主要的磨损机理为氧化磨损、粘结磨损以及磨粒磨损。     

超硬材料复合片及其制造方法

用ⅣA、ⅤA、ⅥA族金属的碳化物、氮化物、碳-氮化物和硼化物与CBN磨粒按约70∶30混合并加入适量的硅和铝作粘结层,将超硬材料层与硬质合金衬底粘结一体做切削工具,并附有试验实例。     

多弧离子镀TiAlSiN梯度涂层制备及切削性能

针对含Si超硬涂层与基体结合强度不足,切削过程中涂层易发生剥落从而导致涂层刀具切削性能低的问题,采用离子源增强的多弧离子镀技术在硬质合金刀具上制备了不同含Si层梯度结构的TiAlSiN梯度涂层。利用XRD、SEM、OM以及切削试验探讨不同含Si层梯度结构对涂层物相、表面形貌、膜基结合强度、摩擦磨损以及切削性能的影响。结果显示：不同含Si层梯度结构的TiAlSiN涂层主要由固溶的（Ti,Al） N和（Al,Ti） N相组成。其中,低Si直接过渡的TiAlSiN涂层（S3）呈现出较高的硬度、良好的膜基结合力、较低的涂层残余应力和摩擦因数。铣削结果显示,涂层刀具的切削磨损机理主要表现为粘着磨损。当切削速度为80 m/min时,低Si过渡涂层（S3涂层）表现出更高的切削长度（925 m）,显著高于S1涂层的525 m;当切削速度由80 m/min增加至110 m/min时,S3涂层切削长度增加到1650 m。对含Si刀具涂层进行梯度设计,可有效提高涂层的膜-基结合强度和涂层刀具的切削性能。     

Analysis of tool wear and residual stress of CVD diamond coated cemented carbide tools in the machining of aluminium silicon alloys

Aluminium alloys have found increasing applications in the automotive and aeronautical industries in recent years. Due to their extraordinary properties however, the machining of these alloys still poses difficulties, and requires the optimized combination of cutting tool material and geometry. The potential of CVD diamond coated carbide tools has been demonstrated in recent years, however tool wear and short tool life remain as issues to be resolved. Key to increasing the tool life of CVD diamond coated tools is the further development of the coating process to optimize the coating adhesion. An understanding of the substrate and coating residual stress profiles must be gained in order to achieve this. Compressive residual stresses in cutting tools can lead to a higher crack resistance, but also to early coating delamination and tool failure. To analyze the influence of residual stresses on the coating quality and tool life, the residual stress profiles of tungsten carbide substrates and CVD diamond coatings were measured using X-ray and synchrotron radiation. The influence of the tungsten carbide substrate type and the CVD diamond coating process on the residual stress profiles was thus determined. In order to analyze the performance of the coated tools and the influence of the residual stresses on the tool lifetime, machining tests were performed with two aluminium silicon alloys. The tool wear, tool lifetime and workpiece quality were examined. Finally, many of the commonly used wear tests used to analyze the wear resistance of tool coatings cannot be implemented for CVD diamond coatings due to their high hardness. An impact test was therefore constructed to allow the determination of the wear resistance of CVD diamond tools.     

Effect of ultrafine gradient cemented carbides substrate on the performance of coating tools for titanium alloy high speed cutting

Gradient cemented carbides usually used as substrate for coating tools, and the substrate has different gradient layer thickness and grain size, which would affect the cutting performance of the coating tools. In this study, different contents of Co and cubic carbonitride were added, the ultrafine gradient cemented carbides with different gradient layer thickness and grain size were prepared by one-step sintering, and then the CAT films (films containing Cr, Al and Ti, basically.) were deposited on alloy surface by Arc Ion Plating (AIP) in Ar gas atmosphere for titanium alloy high-speed cutting. The influence of Co and cubic carbonitride content on the microstructure of alloy and the cutting performance of coated tools was studied. The results show that the gradient layer thickness could be controlled by changing the Co and cubic carbonitride contents, and then affected the cutting performance. The coating tools enhanced cutting performance obviously by reducing the flank wear in the high-speed Ti-alloy cutting. A thinner gradient layer can be formed in alloys that with a lower Co addition, thus leading to tools chipping during high-speed cutting Ti-alloy. The wear resistance and the cutting performance of the tools could be improved by adding cubic carbonitride. The Co10Ti3-CAT coated tool has the best cutting performance. And the wear resistance of Co8Ti4-CAT coated tool can be increased by 50% compared to substrate.     

DLC膜涂层硬质合金刀具的研究进展

类金刚石(DLC)膜涂层刀具的硬度高、摩擦系数低、耐摩擦和耐腐蚀性能强、抗粘结性能好,并且可以用来制作复杂、异型刀具,是未来刀具的一个重要发展方向。本文介绍了DLC膜的表面显微结构和Raman光谱并列举了DLC的制备方法 (包括磁控溅射、离子束沉积、脉冲激光沉积、真空阴极电弧沉积、等离子体增强型化学气相沉积)与分类。从酸蚀法、施加过渡层、表面微喷砂处理和掺杂4个方面分析如何提高膜基结合力,探讨了DLC膜的摩擦性能受湿度、温度和加工条件的影响。例举了几个国内外DLC涂层硬质合金刀具的使用范例,指出了目前研究工作的不足之处,提出了下一步研究工作的重点是优化DLC膜的制备工艺、提高膜基结合力和热稳定性以及加强DLC涂层硬质合金刀具的磨损机理研究。     

Cutting Performance and Wear Behavior of AlTiN-and TiAlSiN-Coated Carbide Tools During Dry Milling of Ti-6Al-4V

Machining, especially dry machining of titanium alloys, has been one of the most significant challenges for carbide cutting tools. In this study, aluminum-rich AlTiN coating, as well as TiAlSiN nanocomposite coating, were successfully employed for dry milling of Ti-6Al-4V alloy with high efficiency and long tool life. At the cutting speeds of 150 m/min and 200 m/min, the tool life of the TiAlSiN-coated tool exceeds that of AlTiN-coated tool by 32 and 66%, respectively. The wear modes for both coated tools include the uniform flank wear, smooth wear, chipping, coating and substrate flaking, crater and notch wear, and the wear mechanisms include adhesion, diffusion, oxidation and crack. Among them, the wear mechanism is dominated by the adhesion and oxidation wear. As compared with AlTiN coating, TiAlSiN coating exhibits better mechanical properties and oxidation resistance, which contribute to a better cutting performance, fewer thermal cracks and smaller and uniform workpiece chips during the dry milling of Ti-6Al-4V alloy.     

Cutting performance of PVD-coated carbide and CBN tools in hardmilling

In this study, cutting performance of CBN tools and PVD-coated carbide tools in end-milling of hardened steel was investigated. In high-speed dry hardmilling, two types of CBN tools were applied: the CBN-rich type and an ordinary one. In the case of relatively low-speed milling, on the other hand, a few coated carbide tools were selected where four kinds of coating films, TiN, TiCN, TiAlN and multi-layered TiAlN/AlCrN, were deposited on the K10 and P30 grade carbide. The cutting performance was mainly evaluated by tool wear, cutting temperature, cutting force and surface roughness. In dry cutting of hardened carbon steel with the ordinary CBN tool, the cutting tool temperature rose rapidly with increase in cutting speed; and tool temperature reached approximately 850 °C at the cutting speed of 600 m/min. In the case of the CBN-rich tool, the cutting temperature decreased by 50 °C or more because of its high thermal conductivity. It is remarkable that tool wear or damage on a cutting tool was not observed even when the cutting length was 156 m in both CBN tools. In the case of coated carbide tools, the temperatures of TiN-, TiCN- and TiAlN-coated carbide tools rose as cutting proceeded because of the progress of tool wear, but that of TiAlN/AlCrN-coated carbide tool hardly rose due to little tool wear. When the base material was K10 grade carbide, tool temperature was lower than that of P30 with any coating. The tool flank wear depends considerably on hardness and oxidizing temperature of the coating film.     

金刚石涂层刀具加工石墨的切削性能

为充分对比不同类型金刚石涂层刀具的切削性能,定制几种不同类型金刚石涂层刀具进行等静压石墨切削加工,并与WC硬质合金刀具和TiAlN涂层刀具的切削情况对比,分析不同类型金刚石涂层刀具的涂层形貌、切削寿命、加工后的表面质量以及切削力。结果表明:制备的金刚石涂层刀具的涂层形貌主要为纳米晶和微晶,其寿命是硬质合金和TiAlN涂层刀具的10倍以上,且几种不同类型的金刚石涂层刀具寿命差异较小;金刚石涂层表面的晶粒细化可以降低加工表面的粗糙度和切削力,涂层脱落是金刚石刀具的主要磨损形式。      

Multi-functional nano-multilayered AlTiN/Cu PVD coating for machining of Inconel 718 superalloy

Machining of Ni-based aerospace alloys is one of the major challenges of modern manufacturing. Application of cemented carbide tooling with nano-multilayered AlTiN/Cu PVD coating results in a significant tool life improvement under conditions of turning the hard-to-machine aerospace Ni-based Inconel 718 superalloy. Studies of the structure, properties, tribological and wear performance of the nano-multilayered AlTiN/Cu PVD coating have been performed. The structure of the coating has been investigated using High Resolution Transmission Electron Microscopy. Various properties of the coating including microhardness, thermal conductivity and coefficient of friction vs. temperature were measured.Investigations of the coated tool life, wear behavior and chip formation for cutting tools with nano-multilayered AlTiN/Cu PVD coating were performed. Morphology of the worn tools has been studied using SEM/EDX. AlTiN/Cu coatings present multi-functionality because they combine self-lubricating behavior with reduced thermal conductivity. This beneficial combination of properties results in significant improvement of the coated tool life.     

CVD金刚石涂层刀具切削性能与磨损机理研究

针对普通刀具切削质量差、刀具耐用度低等问题,对CVD涂层刀具制备方法及切削性能进行研究。首先以硬质合金刀具为基体通过CVD方法制备金刚石涂层,分析涂层表面形貌。然后在不同条件下进行铝合金材料的干式切削试验,分析金刚石涂层对切削力、切削温度以及工件表面粗糙度的影响规律。最后,通过对刀具磨损机理的分析,讨论涂层对刀具使用寿命的影响。研究结果表明,所制备的涂层刀具能够降低切削力和切削温度,大大提高刀具的切削性能和工件的表面质量,并能有效提高刀具使用寿命。     

Analysis of the manufacturing chain of CVD diamond coated shaft type cutting tools

Hypereutectic aluminium silicon alloys, e.g. casted AlSi17Cu4Mg, are commonly used in the automotive and aeronautical industries. These alloys consist of hard, abrasive silicon particles in a soft aluminium matrix and thus place high mechanical loads on the tool during machining processes. Polycrystalline Diamond or CVD (chemical vapour deposition) diamond based cutting tools can be used for the high speed machining of these alloys due to their high hardness and wear resistance. Diamond thin film coatings of different film morphologies are commonly applied on cemented carbide tools using Hot Filament CVD. The distinguishing characteristic to other coatings is utmost hardness resulting in high resistance to abrasion, low tendency to adhesion and low friction coefficient. The manufacturing of CVD diamond coated shaft type cutting tools is challenging due to the complex design of the cutting edges and the demanding stress behaviour during tool application. The influencing parameters of substrate type, chemical and mechanical substrate pre-treatment as well as diamond film modification on the tool cutting performance are discussed. The manufacturing route of CVD diamond coated thread milling drills is analysed with the use of material and tribological tests. The complex thread manufacturing tools are then applied in the machining of AlSi17Cu4Mg, whereby the tool performance is characterised with respect to their wear behaviour, the process forces and temperatures as well as the workpiece quality.