辉光合成TiN/TiB2复合渗镀层摩擦性能的研究

利用等离子尖端放电、空心阴极效应和反应气相沉积技术，在碳钢表面形成具有扩散层和沉积层的TiN渗镀层，然后在此渗镀层表面沉积（PVD法）TiB2薄膜，形成TiN／TiB2复合渗镀层。并且将其与在碳钢基体表面直接沉积（PVD法）TiB2薄膜进行表面形貌、硬度、摩擦磨损性能对比。结果表明：TiN／TiB2复合渗镀层厚度可达十几微米，成分和硬度呈梯度分布，与基体是冶金结合，结合力好，无剥落现象。表面是均匀、致密、细小的胞状组织。表面平均硬度HV 2600，平均摩擦因数小，耐磨性好。     

双辉渗镀TiN陶瓷层摩擦磨损性能的研究

采用一种新的制备TiN双层辉光渗金属技术，在钢铁材料表面直接复合而形成超硬耐磨TiN渗镀扩散陶瓷层。用Tapping AFM型原子力显微镜和LEC图像分析仪分析表面形貌；用GDS750型辉光放电光谱分析仪测定渗镀复合层试样成分；用Rigaku／max2500型X射线衍射仪（XRD）测定复合渗镀层的相结构；用WTM-1E可控气氛微型摩擦磨损试验仪对复合渗镀层的摩擦磨损性能进行研究。结果表明：这种制备TiN新工艺方法合成的渗镀TiN陶瓷层，其表面均匀致密，Ti和N原子由表层向内呈梯度分布，与一般表面沉积的TiN层不同，属于冶金扩散层结合；渗镀层厚度可达8μm以上，TiN层择优取向为（200）晶面；渗镀层硬度较高，达到HV0.1 2200，在干滑动摩擦磨损试验条件下具有较低的摩擦因数和优异的耐磨性能。     

电流作用方式对纳米TiN/Ni复合镀层组织与力学性能的影响

采用添加了纳米TiN的氨基磺酸镍系镀液,利用超声电沉积方法在45钢基体上制备了纳米TiN/Ni复合镀层,对比研究了直流、单脉冲、正负脉冲等3种电流作用方式对镀层表面形貌、纳米TiN含量及分布、界面结合力、显微硬度和摩擦磨损性能的影响。结果表明:与直流电沉积相比,脉冲电沉积镀层的晶粒细小、表面平整、表面裂纹少、界面结合力高,且正负脉冲电沉积的界面结合力高于单脉冲电沉积的;脉冲电沉积更易沉积纳米TiN粒子,且正负脉冲电沉积TiN的沉积速率大于单脉冲的;正负脉冲电沉积镀层的显微硬度最高,摩擦磨损性能最佳,直流电沉积的最差。     

氮化钛镀层技术的引进及应用

一、什么是工具氮化钛镀层技术工具氮化钛镀层技术是用物理气相沉积法(简称PVD)或化学气相沉积法(简称CVD),在工具或模具表面上镀上一层2～5μm金黄色的氮化钛(TiN)硬膜层。因为氮化钛硬度高(可达HV2000,相当于HRC80～85)、摩擦系数低,与基体的结合强度好,化学稳定性好、润滑性好、耐高温、能承受一定程度的弹性变形,故工具经氮化钛镀复后,寿命可提高3～10     

C离子注入对硬质合金刀具TiN涂层性能的影响

在硬质合金刀具上沉积了PVD—TiN涂层,并采用C离子注入技术对其进行表面改性处理。对涂层截面的微观形貌、显微硬度以及与基体附着力的测试结果表明,C离子注入可使TiN涂层的显微组织细密均匀化,并能明显提高涂层的显微硬度以及与基体的附着力。     

基体偏压对磁控溅射制备CrAlN薄膜摩擦学性能的影响

通过分析不同基体偏压下磁控溅射(PVD)CrAlN薄膜的结构特征、硬度规律及磨痕形貌,研究基体偏压对CrAlN薄膜的结构、硬度及摩擦磨损性能的影响。借助扫描电子显微镜(SEM)和原子力显微镜(AFM)观察CrAlN薄膜的表面形貌及三维形貌。采用纳米压痕仪对CrAlN薄膜的硬度进行测定。利用球盘式摩擦磨损试验机测定CrAlN薄膜的摩擦系数,并观察薄膜的磨痕形貌,分析薄膜的磨损机理。结果表明:当基体偏压低于150V时,薄膜表面颗粒的平均尺寸随偏压增大而逐渐减小;当基体偏压超过150V时,薄膜表面出现有明显的缺陷。随着基体偏压的增大,薄膜的硬度呈先升高后降低的趋势,并在基体偏压约为150V时达到最大值为27.5GPa;薄膜的摩擦系数呈先减小后增大的趋势,并在基体偏压约为150V时达到最小值0.25;磨痕呈不同程度的犁沟状,在基体偏压为150V时磨痕形貌平整且犁沟最小。当基体偏压为150V时,CrAlN薄膜的表面缺陷最小、硬度最大、摩擦系数低和综合性能最好,薄膜的磨损机理为磨粒磨损。     

电流密度对氨基磺酸盐镀液电沉积纳米TiN/Ni复合镀层性能的影响

以添加有纳米TiN颗粒的氨基磺酸盐镀液为基础镀液,采用超声-脉冲电沉积的方法在45钢表面制备了纳米TiN/Ni复合镀层,分析了电流密度对其微观形貌、显微硬度以及表面TiN含量及分布的影响。结果表明:当电流密度在2~5A·dm~(-2)时,复合镀层结构致密且厚度均匀,其厚度随电流密度的增大而增加;随着电流密度的增大,复合镀层表面晶粒先细化后长大,显微硬度先提高后降低,当电流密度为4A·dm~(-2)时,镀层表面平整,表面和截面硬度均达到最大,分别为677,763HV;复合镀层表面TiN的含量随电流密度的增大先增加后减少,当电流密度为4A·dm~(-2)时,其含量最高且分散均匀。     

物理气相沉积TiN薄膜疲劳磨损形貌的AFM观测

采用物理气相沉积工艺在高速钢表面沉积TiN薄膜,研究了TiN薄膜的疲劳磨损过程。采用原子力显微镜(AFM)观测分析了表面疲劳点蚀的形貌特征。试验结果表明:较厚TiN薄膜具有较低的疲劳磨损寿命,而较薄的TiN膜层具有较高的疲劳磨损寿命。在试验的初始阶段,磨损轨迹上都出现大量显微凹坑,AFM观测分析可知显微凹坑起源于薄膜表面,呈菱形状。随试验的进行,较薄的TiN薄膜出现典型的疲劳麻坑,而较厚的TiN薄膜在薄膜与基体的界面处形成疲劳裂纹,并出现严重的剥层和断裂。     

不同方式电沉积纳米TiN/Ni复合镀层的组织和耐磨损性能

采用直流电沉积、脉冲电沉积和超声-脉冲电沉积三种方式在45钢表面制备了纳米TiN/Ni复合镀层,分析了复合镀层的组织、显微硬度以及镀层中TiN的含量,并对复合镀层的耐磨损性能进行了研究。结果表明:直流电沉积复合镀层的晶粒最粗大,超声-脉冲电沉积复合镀层的晶粒尺寸最细小;直流电沉积复合镀层、脉冲电沉积复合镀层和超声-脉冲电沉积复合镀层的显微硬度以及镀层中TiN的含量依次增大;超声-脉冲电沉积复合镀层具有最佳的耐磨损性能,其磨损量为直流电沉积复合镀层的46%,显微硬度为604.72HV,镀层中TiN的质量分数为2.27%。     

化学复合镀Ni-P-SiC-MoS2镀层的研究

利用化学镀的方法在GCr15钢的基体上沉积了N i-P-SiC-MoS2复合镀层,借助于扫描电镜、X衍射分析仪、显微硬度计、M-2000型磨损试验机等设备对复合镀层的表面形貌、成分、结构、硬度及其耐磨性等作了综合分析。结果表明,SiC、MoS22种粒子同时加入N i-P合金基质中所得到的N i-P-SiC-MoS2复合镀层镀态时为非晶态结构,且复合镀层的硬度低于N i-P-SiC而高于N i-P-MoS2镀层;N i-P-SiC-MoS2复合镀层摩擦磨损性能最好,是一种具有良好耐磨性及自润滑性的复合镀层。     

Tribological evaluation of TiN and TiAlN coated PM-HSS gear cutter when machining 19MnCr5 steel

Two PVD coated powder metallurgy high speed steel (PM-HSS) gear cutters were investigated when machining helical gears made from AISI 19MnCr5 steel with hardness between 140 and 180 HV. Machining trials were carried out with gear cutters coated with TiAlN (nano layers) and TiN (mono layer). Crater and flank wears were measured and analysed after all the machining trials. Analyses of the worn tools show that the TiAlN coated gear cutter performed better than the TiN coated gear cutter. This can be attributed to its nano layers and the higher hardness of the TiAlN coating. The dominant tool wear mechanisms were adhesion, abrasion, delaminating of the coating layer and chipping of the cutting edge.     

复合氮化合物薄膜的研究

采用多源PVD技术在YG8硬质合金基体上分别沉积了Ti N和Ti NX薄膜,利用X射线衍射仪、扫描电子显微镜以及多功能材料表面试验仪,研究了多种元素的添加对Ti N涂层微观结构、断口和表面形貌的影响。结果表明:添加多种元素可使Ti N涂层的微观结构发生明显变化,能有效控制膜的结晶和生长模式,改变传统的(111)面的单一取向,从原来的(111)的择优取向,转变为(200)、(111)、(220)共同取向;Ti NX涂层的断口呈非柱状结构,表面粗糙度小于Ti N,具有更为均匀致密的结晶结构和光整的表面形貌,趋于Ti Al N薄膜的显微硬度,一致的结晶组织结构、有效的沉积效率、良好的膜基结合力有利于厚膜Ti N的制备;相对于Ti N,寿命可提高50%-100%。     

Abrasive Wear of DLC/PVD Multilayer Coatings: AFM Studies

The tribological behaviour of multilayered coatings deposited on plain carbon steel was investigated by microscale abrasion tests (MSATs). The multilayered coatings consisted of an outer diamond‐like carbon (DLC) layer, a physical vapour deposition (PVD) nitride‐based interlayer, and an inner electroless Ni‐P layer. PVD TiN‐ and Ti(C,N)‐coated samples with and without the DLC outer layer were studied in order to evaluate the influence of each layer on the tribological behaviour of the multilayer‐coated system. The MSATs were carried out using a device based on ball‐cratering geometry: a hard steel sphere was rotated against the coated specimen in the presence of an aqueous suspension of SiC particles. The wear coefficients of the multilayers were calculated from the diameter of the wear craters. The morphology of the wear scars produced by the MSATs was studied by atomic force microscopy (AFM). The wear damage was described by measuring the r.m.s. roughness (S_q) on the sides of the wear craters. Roughness values were related to the wear coefficients (k_c) for the different multilayers on the basis of mathematical elaboration typical of the ‘design of experiment’ (DOE) statistical technique. The presence of the DLC outer layer reduced the roughness of the crater sides and significantly increased the wear resistance of the multilayer only in the case of the PVD TiN sublayer.     

A comparative study on performance of multilayer coated and uncoated carbide inserts when turning AISI D2 steel under dry environment

The present work deals with a comparative study on flank wear, surface roughness, tool life, volume of chip removal and economical feasibility in turning high carbon high chromium AISI D2 steel with multilayer MTCVD coated [TiN/TiCN/Al₂O₃/TiN] and uncoated carbide inserts under dry cutting environment. Higher micro hardness of TiN coated carbide samples (1880 HV) compared to uncoated carbide (1430 HV) is observed and depicts better resistance against abrasion. The low erosion rate was observed in TiN coated insert compared to uncoated carbide. The tool life of TiN coated insert is found to be approximately 30 times higher than the uncoated carbide insert under similar cutting conditions and produced lower surface roughness compared to uncoated carbide insert. The dominant wear mechanism was found to be abrasion and progression of wear was steady using multilayer TiN coated carbide insert. The developed regression model shows high determination coefficient i.e. R² = 0.977 for flank wear and 0.94 for surface roughness and accurately explains the relationship between the responses and the independent variable. The machining cost per part for uncoated carbide insert is found to be 10.5 times higher than the multilayer TiN coated carbide inserts. This indicates 90.5% cost savings using multilayer TiN coated inserts by the adoption of a cutting speed of 200 m/min coupled with a tool feed rate of 0.21 mm/rev and depth of cut of 0.4 mm. Thus, TiN coated carbide tools are capable of reducing machining costs and performs better than uncoated carbide inserts in machining D2 steel.     

双层辉光等离子渗金属技术制备TiN渗层及其耐NaOH溶液腐蚀性能

采用双层辉光等离子渗金属技术在Q235钢表面上制备了TiN渗层;对渗层的组织、硬度、成分和相结构及其耐NaOH溶液腐蚀性能进行了研究.结果表明:该渗层是由TiN颗粒均匀分布的扩散层及表面TiN沉积层组成的梯度结构;渗层表面形貌为胞状组织,颗粒致密均匀,表面为金黄色,渗层厚度可达16μm,与基体实现了冶金结合;渗层表面钛...     

The abrasive wear of steels in South African soils

A high carbon steel was heat treated to produce a range of microstructures and mechanical properties. These steels were subjected to abrasion testing in stony, clay, and sandy soils. Wear rates were found to be twenty times higher in stony soil than in sandy soil and seven times greater than in clay. It was found that the relative wear resistance increased in sandy and clay soils with increase in steel hardness. In stony soils the relative wear resistance of all steels was found to be similar. An explanation for such behaviour was formulated on the basis of surface temperature heating and work hardening effects. The aggressive nature of abrasion found in stony soils was also found to give rise to the appearance of very hard white layers on the steel surfaces.     

Wear resistance and anti-sticking properties of duplex treated forming tool steel

The aim of this work was to investigate the potential of using hard physical vapour deposition (PVD) coatings on forming tools, as well as to determine the influence of plasma nitriding on the load-carrying capacity and wear resistance of coated tool surfaces. A load-scanning test rig was used for evaluation, where duplex treated cold work tool steel samples were loaded against soft austenitic stainless steel and hardened ball bearing steel, respectively. Four different coatings (TiN, TiB₂, TaC and DLC) and two substrate treatments (hardening and plasma nitriding in two different gas mixtures) were included.Plasma nitriding alone significantly improved the friction, wear, and anti-sticking properties of the tool steel. PVD coating, and especially PVD coating of nitrided tool steel further improved the performance. Therefore, from the point of view of tool life as well as work peace surface quality, the DLC coating with its excellent anti-sticking properties and sufficiently good wear resistance represent the best solution for forming tool applications of austenitic stainless steel.     

TiN、CrN的环境摩擦磨损对比研究

采用直流叠加脉冲偏压电弧离子镀技术在45钢表面沉积了TiN、CrN薄膜。用显微硬度计测试了薄膜的硬度,用划痕仪测量了薄膜的膜基结合力,用球-盘式摩擦磨损试验机评价了不同介质条件下（干摩擦、水润滑、油润滑）TiN、CrN薄膜的摩擦学特性,用表面轮廓仪测试了薄膜磨痕处的磨损轮廓,用扫描电镜（SEM）观察了薄膜磨痕形貌。结果表明,相对于干摩擦条件下,在水润滑和油润滑条件下TiN和CrN薄膜的摩擦因数和磨痕深度都有所降低。在相同的介质条件下,CrN薄膜的摩擦因数和磨痕深度始终小于TiN薄膜。     

A comparative study on the microstructure and tribological properties of Si3N4 and TiN films produced by the IBED method

The tribological properties of Si₃N₄ and TiN thin films produced by ion beam enhanced deposition (IBED) were compared on a SRV friction and wear testing machine. The friction coefficient of all thin films shows a descending tendency with increase in load, and is lower than that of 52100 steel. All the IBED films show a much better wear resistance than 52100 steel, especially in the higher load and frequency ranges; it can reach six times that of the latter. In order to understand the reasons for their excellent properties, the microstructure, microhardness and bonding strength with the substrate were analysed by SEM, X-ray diffraction, Knoop hardness and scratching test methods separately. The results show that the TiN(1) film exhibits the best tribological properties, which are closely related with its greater hardness and bonding strength.