陶瓷膜对牙轮钻头滑动轴承摩擦磨损性能的影响

采用化学气相沉积（CVD）和物理气相沉积（PVD）工艺,分别选用高铝钛及TiC+ Ti(C, N) +TiN复合的金属陶瓷在滑动轴承表面制备金属陶瓷膜层。采用金相显微镜（OM）、体视显微镜和显微硬度计对不同金属陶瓷膜的表面形貌、组织结构及厚度进行测量和观察,并在MMW-1型万能摩擦磨损试验机对涂层材料进行摩擦磨损试验,通过测量磨损量与摩擦因数随时间的变化规律,观察摩擦副表面磨损形貌,分析了不同陶瓷膜层的耐磨性和摩擦磨损机理。结果表明,涂镀复合陶瓷膜（TiC/Ti(C, N)/TiN）的销试件硬度高、磨损极其轻微、表面质地均匀且光滑,复合陶瓷膜（淬火）更适用于牙轮钻头滑动轴承表面涂层材料。     

抛光涂层硬质合金刀片加工钛合金的耐用度分析

目的提高涂层硬质合金刀具加工钛合金的切削性能及加工效率。方法采用化学机械抛光(Chemical Mechanical Polishing,CMP)对经过磨削加工的YG8硬质合金车削刀片前刀面进行抛光预处理,并使用CVD与PVD涂层工艺制备涂层。运用单因素试验法,对抛光涂层硬质合金刀片进行切削TC4钛合金的刀片耐用度试验,分析钛合金加工过程中刀具种类及切削参数变化对刀片耐用度的影响规律。采用扫描电子显微镜(SEM)和能谱仪(EDS)分析刀片的磨损机理。结果经过化学机械抛光处理后,硬质合金刀片的平均粗糙度由87 nm降低为19 nm,降低幅度达78.2%。相同切削参数时,抛光CVD硬质合金刀片的耐用度最大程度上比磨削CVD硬质合金刀片提高了75%,抛光PVD硬质合金刀片的耐用度最大程度上比磨削PVD硬质合金刀片提高了8.3%。可见采用化学机械抛光对硬质合金刀片进行加工是提高刀片表面平整度及耐用度的重要途径。结论抛光CVD硬质合金刀片的耐用度优于磨削CVD硬质合金刀片,抛光PVD硬质合金刀片的耐用度优于磨削PVD硬质合金刀片。     

镍基金属陶瓷涂层在人工海水中的摩擦学性能

目的探讨镍基金属陶瓷涂层在海水中的耐腐蚀磨损性能。方法采用激光熔覆技术在45钢表面制备了1.1 mm厚的镍基金属陶瓷涂层。采用电化学测试系统,对比分析了涂层的耐蚀性。采用往复式摩擦磨损试验机,测量了涂层在干摩擦及海水环境下的摩擦系数。采用扫描电镜等手段分析了涂层和磨痕的表面形貌。结果镍基金属陶瓷涂层的表面硬度约为基体的3倍,且硬度较均匀。在结合区开始,硬度剧烈下降,直至降为基体硬度。在3.5%Na Cl溶液中,镍基金属陶瓷涂层的腐蚀倾向低于316L不锈钢及316L堆焊层,而腐蚀速率介于两者之间。干摩擦条件下,镍基金属陶瓷涂层明显降低了基体的摩擦系数(从0.58降低至0.49)和磨损量(降低了50%)。与干摩擦实验相比,人工海水明显降低了镍基金属陶瓷涂层的摩擦系数(从0.49降低至0.37)和磨损量(降低了40%)。结论由于具有良好的耐蚀性和较高的硬度,镍基金属陶瓷涂层在人工海水中表现出了良好的耐磨耐蚀性能。磨损过程中,人工海水的冷却、润滑作用和其中盐类的隔离作用,有效改善了摩擦界面的接触状态,提高了镍基金属陶瓷涂层的耐磨性。     

TiN/TiAlN涂层Ti(C,N)基金属陶瓷刀具的切削性能

采用多弧离子镀技术在Ti(C,N)基金属陶瓷基体上沉积了TiN/TiAlN多层涂层,通过扫描电镜、涂层附着力自动划痕仪对其显微组织形貌和涂层的结合强度进行了分析,并对涂层和未涂层金属陶瓷铣刀以及硬质合金铣刀进行了切削0Cr18Ni9钢的试验.结果表明,多弧离子镀TiN/TiAlN涂层均匀,TiN/TiAlN多层涂层与金属陶瓷之间的结合强度高达57.52 N.TiN/TiAlN涂层金属陶瓷的切削性能明显优于未涂层金属陶瓷和硬质合会YW2,其平均寿命为硬质合金刀具的2倍.TiN/TiAlN涂层金属陶瓷刀具的失效形式主要是磨损和崩刃,没有涂层剥落现象,TiN/TiAlN涂层与基体的结合强度很好.未涂层金属陶瓷刀具的磨损形式主要是磨损和粘着.     

PVD涂层刀具高速铣削CoCrMo合金的性能研究

目的为了提高涂层硬质合金刀具的切削性能,研究了物理气相沉积PVD法制备的涂层硬质合金铣刀在高速干式环境下的铣削性能。方法采用阴极电弧技术制备了TiN、TiAlN以及TiAlSiN涂层硬质合金铣刀刀头,通过一同沉积涂层的硬质合金圆片,间接测量得出涂层的显微硬度、厚度和平均摩擦系数,并以CoCrMo合金为切削对象,进行了PVD涂层与无涂层刀具高速铣削下的对比试验。结果TiAlSiN显微硬度最高达3800HV,摩擦系数达0.3,TiAlN涂层平均膜厚为2μm,间接测得TiN、TiAlN以及TiAlSiN涂层的结合力依次为60、58、42N。在三者的切削性能中,TiAlSiN涂层的切削性能比TiAlN和TiN涂层的好,同等切削参数时,TiN刀具的高速铣削时间最短,TiAlSiN涂层的平均磨损值为0.1895,TiN的平均磨损值为0.3047。结论涂层中添加Al、Si,极大地提高了刀具的使用性能,改善了刀具切削过程中的耐磨性、红硬性,极大地延长了刀具的使用寿命。TiAlSiN涂层的硬度高,耐磨损性好,切削性能好,适合高速铣削加工。     

大气等离子喷涂TiB2-316L不锈钢基复合涂层及其耐磨性能

分别采用高能球磨制备了TiB2含量(质量分数)为10%的316L不锈钢基复合粉,高能球磨与喷雾干燥造粒工艺制备了TiB2含量(质量分数)为40%的316L不锈钢基复合粉,大气等离子喷涂制备相应的TiB2-316L不锈钢基金属陶瓷涂层与316L不锈钢涂层.室温下采用高速环块磨损试验研究TiB2-316L不锈钢基金属陶瓷涂层的磨损特性.采用X射线衍射分析涂层物相,扫描电镜分析喷涂粉末、涂层结构和摩擦副磨损表面形貌.结果表明,大气等离子喷涂两种制粉工艺获得的316L不锈钢基TiB2复合粉能获得较耐磨的316L不锈钢基TiB2复合涂层,耐磨性高于316L不锈钢涂层,且TiB2在复合涂层中增强涂层耐磨性的原因是TiB2颗粒在涂层316L韧性基体中充当强化相,且TiB2在摩擦接触处摩擦氧化形成的氧化产物具有自润滑特性,能减少涂层的磨损量.     

CVD金刚石涂层刀具在石材铣削中的磨损特性研究

为了揭示CVD金刚石薄膜涂层刀具在硬脆材料切削中的刀具切削性能与磨损机理,利用不同沉积参数下的金刚石涂层刀具对天然石材进行了高效铣削实验。针对金刚石涂层刀具和未涂层硬质合金刀具的磨损周期和切削性能,分析刀具切削力和工件表面粗糙度随后刀面磨损面积的变化规律,总结刀具磨损机理。实验结果表明:金刚石涂层刀具切削寿命高于未涂层硬质合金刀具;金刚石刀具的磨损周期可以分为初始磨损区、稳定磨损区和加剧磨损区3个阶段,其中甲烷浓度为1%的金刚石涂层刀具寿命较长,切削性能稳定;金刚石涂层刀具的磨损机理主要包括裂纹作用下的涂层剥落、涂层内部晶间断裂和粘结磨损,其中裂纹作用下的膜-基涂层剥落磨损为刀具失效的主要磨损机制。     

TiAlN涂层与Al_2O_3复合涂层刀具高温合金切削性能研究

为提升高温合金加工刀具的加工质量与效率,设计制备了用于金属陶瓷刀具的TiN/Al_2O_3/TiC/TiCN复合涂层(Al_2O_3复合涂层)与用于硬质合金刀具的TiAlN涂层。开展了进给量为单因素变量的切削实验,并从切削力变化、刀具磨损情况及被加工表面质量三方面验证对比刀具的切削性能。试验表明,涂层刀具的刃口钝化处理导致了其加工过程切削力的升高,其中TiAlN涂层硬质合金刀具切削力变化较平稳;Al_2O_3复合涂层刀具加工过程中出现了涂层剥落现象,而TiAlN涂层刀具磨损较小;TiAlN涂层硬质合金刀具获得的加工表面质量优于Al_2O_3复合涂层刀具。TiAlN涂层硬质合金刀具在耐磨性、涂层粘着力及加工质量三方面均优于Al_2O_3复合涂层金属陶瓷刀具。     

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。     

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。     

Assessment of 3D printed steels and composites intended for wear applications in abrasive,dry or slurry erosive conditions

The design of earth cutting and machining tools generally requires the application of several types of materials with different wear resistance: (1) base metal with low wear resistance, (2) extremely resistant cutting inserts made of ceramics (or even diamond), cemented carbides or cermets and (3) thick coatings with average wear resistance to protect base metal or thin (PVD or CVD) coatings to improve wear resistance of inserts. The production of such tools is complicated, tedious and not very efficient (tool life depends on the interface bonding, brazed inserts can be severely damaged after impact, base material wear, etc.). The novel approach is to exclude the steps of brazing or coating and to produce steels or composites with similar wear resistance as that of inserts or coatings using the promising approach of additive manufacturing (AM i.e. 3D printing). Moreover, benefits of AM like near net shape part building with complex internal features (internal cooling channels) are desired for cutting tools. The aim of the current research is to assess novel commercially available 3D printed steels and composites in several relevant tribological conditions where these materials could be applied. The comparison with conventional Hardox 400 wear resistant steel and AISI 316 stainless steel is provided. Results report significant improvement in the wear resistance of AM produced steels and composites against reference materials. The performance of 3D printed materials lie between WC- based bulk cemented carbides and hardfacings. The characteristic features of wear mechanisms are presented and discussion is supported by Scanning Electron Microscope images.     

MILLING PERFORMANCE OF COATED INSERTS WITH VARIABLE COATING THICKNESS ON THEIR RAKE AND FLANK

During the Physical Vapour Deposition of coatings, the orientation of cemented carbides insert surfaces to the plasma flux direction affects the occurring film thickness distribution on the rake and flank, which in turn might influence the wear propagation in cutting processes. In the present paper the cutting performance in milling of PVD coated cemented carbides inserts with variable film thickness on the rake and flank is introduced and with the aid of FEM-supported calculations explained. The investigation results revealed that a thicker film on the tool rake in comparison to the existing one on the flank and moreover a thick and uniformly deposited film in the cutting wedge region significantly enhances the cutting performance in milling.     

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.     

Effect of number of layers on erosion,corrosion, and wear resistance of multilayer Cr–N/Cr–Al–N coatings on AISI 630 stainless steel

In the present study, multilayered Cr–N/Cr–Al–N coatings were prepared by cathodic arc physical vapor deposition (PVD) with different numbers of layers and the same total thickness on AISI 630 steel in an attempt to improve the wear and erosion–corrosion resistance. Structural analysis of the coatings was performed by field scanning electron microscopy, X-ray diffraction (XRD), and energy-dispersive spectroscopy. Depth profiles and roughness parameters of worn surfaces were calculated after erosion and wear tests. XRD indicated that nitride compounds were formed in multilayer coatings by PVD. The Cr–N/Cr–Al–N coating exhibited superior corrosion resistance compared with AISI 630 substrate. The erosion–corrosion results revealed that the smoothest wear track with the minimum erosion rate and wear depth was obtained for five- and seven-layered coatings. The failure mechanism of the bare substrate was influenced by plastic deformation via cutting and plowing, while the failure mechanism for coated samples was chipping and delamination. According to the wear results, the multilayer coatings showed a lower friction coefficient and better surface morphology that demonstrated their high ability for wear protection.     

Wear mechanisms of PVD ZrN coated tools in machining

Medium-frequency magnetron sputtered PVD ZrN coatings (ZrN, ZrN/Zr) were deposited on YT15 (WC + 15%TiC + 6%Co) cemented carbide. Microstructural and fundamental properties of these ZrN coatings were examined. Dry machining tests on hardened steel were carried out with these coated tools. The wear surface features were examined by scanning electron microscopy. Results showed that deposition of the PVD ZrN coatings onto the YT15 cemented carbide causes great increase in surface hardness. The ZC-1 coated tool (ZrN/YT15 without interlayer) has the highest surface hardness; while the ZC-2 (ZrN/Zr/YT15 with a Zr interlayer) shows the highest adhesion load for the coatings to the substrate. The ZrN coated tools exhibit improved rake and flank wear resistance to that of the YT15 tool. The coated tools with a Zr interlayer (ZC-2) have higher wear resistance over the one without Zr interlayer (ZC-1). The rake wear of the ZrN coated tools at low cutting speed was mainly abrasive wear; while the mechanism responsible for the rake wear at high cutting speed was determined to be adhesion. Extensive abrasive wear accompanied by small adhesive wear were found to be the predominant flank wear mechanisms for the ZrN coated tools.     

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.     

Cutting and wear behaviors of TiC based cermets cutter with nano-TiN modification

1　INTRODUCTIONCermethasbeenwidelyusedasatoolmaterialowingtoitsgoodcomprehensivepropertiessuchashighhardness ,hightransverserupturestrength ,goodchemicalstabilityandexcellentwearresis tance[1] .Inaddition ,TiCbasedcermetsappearedin1930sanddevelopedveryquicklyafter 1980s[2 ] .Ear lyTiCbasedcermetscutterfindlimitedapplicationbecauseofitslowermechanicalproperties .Subse quentinvestigationfindsthatadditionofTiNaidstotheimprovementofmechanicalpropertiesbecauseoftherefiningeffectoftheTiCmatr…     

Characterization and properties of MTCVD Ti(C,N) coated cemented carbide substrates with Fe/Ni binder

Two developments, including the deposition of hard chemical vapour deposition (CVD) coatings on cemented carbides and the use of innovative binders instead of Co for cemented carbides, have attracted worldwide interest. In this paper, ISO grade P30 cemented carbides with Fe/Ni and Co binders are prepared as the substrates, and adherent Ti(C,N) coatings are deposited on them by moderate temperature chemical vapour deposition (MTCVD) technique. The microstructure and properties of both the substrates and coated cemented carbides are studied.