不同过渡层对DLC薄膜力学性能和摩擦学性能的影响

薄膜与基体间的界面结合性能是决定薄膜性能发挥的关键要素。针对类金刚石薄膜(DLC)在硬质合金上结合力差的问题,采用线性阳极离子束复合磁控溅射技术在硬质合金YG8基体上设计制备了单层W过渡层、WC过渡层、双层W过渡层和三层W过渡层4种不同W过渡层的DLC薄膜,探讨了不同过渡层对DLC薄膜力学和摩擦学性能的影响。结果表明:不同过渡层结构的DLC薄膜结构致密,界面柱状生长随着层数增加及过渡层厚度的降低而打断,有利于改善薄膜的韧性。当为三层W过渡层时,DLC薄膜的断裂韧性达到最大值6.44 MPa·m1/2;与单层W过渡层相比,薄膜硬度有小幅下降,但薄膜内应力降低了55%,且膜/基匹配性更佳,结合强度高达85N,此时薄膜具有较低的摩擦因数和磨损率,表现出比较优异的抗磨减摩性能。     

Cr基过渡层对钛合金表面类金刚石薄膜摩擦学性能的影响

采用磁控溅射技术在钛合金(Ti6Al4V)表面制备Cr、Cr/Cr N和Cr/Cr N/Cr NC过渡层结构的类金刚石(DLC)薄膜。采用扫描电子显微镜、拉曼光谱仪与原子力显微镜分析薄膜的结构和表面形貌,利用纳米压痕仪、薄膜内应力测试仪、划痕测试仪、摩擦试验机和二维轮廓仪研究薄膜的硬度、内应力、结合力和摩擦磨损性能。结果表明:随着Cr基梯度过渡层的引入,DLC薄膜的内应力逐渐下降,结合力逐渐上升。Cr/Cr N/Cr NC/DLC薄膜具有优异减摩抗磨性能,摩擦因数和磨损率低至0.09±0.02和(1.89±0.15)×10-7 mm3/N·m。试验结果对钛合金表面高性能DLC薄膜制备及应用具有一定的参考价值和指导意义。     

线性离子束制备DLC薄膜的结构和性能

为研究线性离子束技术在不同基体材料上沉积DLC薄膜的结构和性能,分别在YG6硬质合金、SKD11不锈钢和T7451铝合金表面沉积DLC(类金刚石)薄膜,并采用Cr作为过渡层,缓解膜基不匹配性。通过原子力显微镜、台阶仪和Raman光谱研究薄膜的表面形貌和微观结构;利用划痕仪和摩擦磨损试验机对薄膜膜基结合强度及耐磨性进行测试。结果表明:采用该技术制备的DLC薄膜均匀光滑,表面粗糙度Ra仅为5.5nm;DLC/Cr/SKD11膜系的ID/IG值低于DLC/Cr/YG6膜系和DLC/Cr/T7451膜系,说明沉积于SKD11表面的DLC含有较多的sp3 C;DLC/Cr/SKD11和DLC/Cr/T7451膜系膜基结合强度为42.2N和23.2N,而DLC/Cr/YG6膜系在120N载荷范围内未有明显破损脱落,结合强度最好;DLC/Cr/YG6膜系摩擦因数(0.09)小于DLC/Cr/SKD11膜系(0.14)和DLC/Cr/T7451膜系(0.32),说明其具有较好耐磨性能。由此看出,不同基体上制备的DLC薄膜结构不同,结合强度和耐磨性也有所差别。     

硬质合金微细刀具多种硬质涂层的研究

不同的刀具涂层具有不同的特性,为了寻找一种综合性能适用于微细刀具表面涂覆的涂层,本文在微细刀具基体材料硬质合金表面涂覆了包括微米金刚石(MCD)、纳米金刚石(NCD)、微纳米金刚石(MNCD)、普通类金刚石(DLC),含氢类金刚石(DLC-H)、四面体非晶碳类金刚石(TaC)薄膜及其复合薄膜在内的16种硬质薄膜。采用扫描电镜、三维白光干涉仪、洛氏硬度计、自制动载荷冲击试验机和摩擦磨损实验机分别表征了薄膜的微观表面和截面形貌、表面粗糙度、静和动载膜基结合强度及干摩擦学性能。实验发现,TaC薄膜虽在静和动载荷作用下,其膜基结合强度逊于DLC和DLC-H薄膜,但其表面光洁度,摩擦学性能明显优于DLC和DLC-H薄膜,可作为优秀的表面涂层。同时,将TaC薄膜与MNCD薄膜相结合,所得的MNCD+TaC薄膜兼具了底层MCD耐磨,中间NCD吸收冲击载荷,表层TaC薄膜光洁的优点,在所有薄膜中具有最低的摩擦系数和磨损率。     

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。     

钛合金表面百微米级Ti/TiN多层复合涂层性能研究

目的提高TiN硬质涂层的厚度及各项力学性能。方法采用等离子增强PVD技术在钛合金(TC4)基体表面制备多层复合Ti/TiN涂层,对涂层进行扫描电镜(SEM)分析,采用划痕法表征涂层的结合强度,用维氏显微硬度计测试涂层的显微硬度,利用销盘式摩擦磨损试验仪评价涂层的摩擦磨损性能。结果制备的多层复合Ti/TiN涂层厚度最高可达100μm,且未发生剥落等失效,结合强度相对于单层TiN提高了近3倍。由于Ti、TiN的多层复合调制作用,制备的Ti/TiN显微硬度测试表明复合涂层的显微硬度高达2700 HV0.025,同时,涂层在原有耐磨性能优良的基础上具备自润滑减摩作用,经过近20 000 m的磨损测试,复合涂层的摩擦系数低至0.25左右,且未完全失效。结论多层复合结构能够有效提高TiN硬质涂层的厚度,制备的Ti/TiN多层复合涂层的各项力学性能显著提高。     

掺Ti量对类金刚石薄膜机械性能的影响

采用非平衡磁控溅射技术,通过改变Ti靶溅射电流,在不锈钢衬底表面沉积了不同掺Ti量的类金刚石薄膜(Ti-DLC),研究了掺Ti量对薄膜的显微硬度、弹性模量、膜/基结合强度、断裂韧性及摩擦磨损行为的影响。结果表明:DLC薄膜掺杂Ti后,硬度明显提高,且随着Ti靶溅射电流的增大,薄膜硬度先增加、后降低,Ti靶溅射电流为1.5A时,薄膜硬度最高;掺杂适量的Ti,可以明显改善DLC薄膜的膜/基结合强度和断裂韧性,并能明显降低DLC薄膜的摩擦系数。     

离子辅助沉积TiN/Ti复合膜提高TC17钛合金高温微动疲劳抗力

为提高钛合金高温微动疲劳抗力,利用离子辅助电弧沉积技术在TC17钛合金表面制各了TiN/Ti复合膜层,研究了膜层的剖面成分分布、膜基结合强度、膜层显微硬度、韧性、常规摩擦学性能以及抗高温微动疲劳性能.结果表明:利用离子辅助电弧沉积技术可以获得硬度高、韧性好、膜基结合强度和承载能力优异的TiN/Ti复合膜层,该膜层具有良好的抗磨和减摩性能,能够显著地提高TC17钛合金在350℃高温环境下的常规磨损和微动疲劳抗力.然而,TC17钛合金表面喷丸强化后进行离子辅助沉积TiN/Ti复合膜,由于喷丸层残余压应力的显著松弛以及膜层易于开裂和脱落的缘故,微动疲劳抗力则不及喷丸强化或TiN/Ti复合膜单独作用.     

PVD涂层技术制备类金刚石薄膜及性能研究综述

介绍了采用物理气相沉积(PVD)技术制备类金刚石涂层的方法,进而论述了涂层的摩擦磨损和结合力等性能的研究现状和发展前景。分析并综述了类金刚石涂层的技术发展,以及制备类金刚石薄膜的方法和影响其性能的多种要素。表面涂有类金刚石薄膜的工件具有较高的硬度、良好的热传导率、极低的摩擦系数、优异的电绝缘性能等。类金刚石薄膜(DLC Films)是近年来兴起的一种以sp3和sp2键的形式结合生成的亚稳态材料,因其优异的减摩和抗磨性能,在摩擦学领域获得了广泛应用,是一种与金刚石涂层性能相似的新型薄膜材料。DLC涂层的性能研究大多集中在它的摩擦学特性和结合力性能,并且作为优质的涂层材料已被广泛应用于汽车、模具、刀具等领域。     

WC基硬质合金CVD涂层的组织与性能

利用X射线衍射研究了CP3型硬质合金涂覆 5层 (TiC TiNC TiC TiCN TiN)硬质层的组织 ,用扫描电镜观察了涂层的断口形貌 ,用划痕法测定了涂层与基体的结合力 ,用三点弯曲方法测定了涂覆前后硬质合金的抗弯强度 ,并用Weibull统计方法对其进行了分析。结果表明 :涂层组织由TiC ,TiC0 .2 N0 .8和TiN组成 ,涂层中无发达的柱状晶 ,涂层与基体结合良好 ,涂覆后硬质合金的抗弯强度有所下降 ,但分散性却减小     

Improvement of the wear resistance of Ti-based coating sliding against copper alloy

The multilayer coating, Ti10%-C:H/TiC/TiCN/TiN, was deposited on cemented tungsten carbide (WC-Co) substrate by an unbalanced magnetron sputtering system. Tribological characteristics of this coating were compared with the coatings of TiN, TiCN, and TiC/TiCN/TiN deposited on WC-Co substrates and the WC -Co substrate itself. The coating displayed excellent tribological properties, i.e., both low value and smooth curve of friction coefficient, and also, compared with the other tested materials, yielded the lowest wear depth when sliding against bronze under dry conditions. The coating thus protects against the high wear experienced when Ti-based coatings rub against copper alloy.     

Triode plasma nitriding and PVD coating: A successful pre-treatment combination to improve the wear resistance of DLC coatings on Ti6Al4V alloy

Diamond-like carbon (DLC) coatings have found great applicability in the automotive industry because of their low friction coefficient and high wear resistance. Nevertheless, their tribological performance can be greatly reduced on soft substrates such as titanium alloys. The hard DLC coating cannot usually follow elastic and plastic deformation of the substrate without failing. In order to overcome this property mismatch between hard coating and soft substrate, triode plasma nitriding was applied as a pre-treatment to improve the mechanical properties of the Ti6Al4V alloy and further enhance the load support for the DLC coating. DLC and multilayered TiN/DLC, CrN/DLC CrAlN/DLC coatings were deposited onto “standard” and plasma nitrided Ti6Al4V substrates. Triode plasma nitriding increased the load-bearing capacity of the coating/substrate system, as higher critical adhesion loads were recorded for DLC coatings on plasma nitrided Ti6Al4V substrates. This treatment also reduced the wear rate of the DLC coating/substrate. Further load support and lower wear rates were achieved by using TiN, CrN and CrAlN as intermediate layers on plasma nitrided Ti6Al4V substrates.     

Effect of micro-blasting on the tribological properties of TiN/MT-TiCN/Al2O3/TiCNO coatings deposited by CVD

The effect of micro-blasting on the tribological properties of TiN/MT-TiCN/Al₂O₃/TiCNO coatings was studied. The multilayer coatings were deposited on cemented carbides by chemical vapor deposition. The microstructure, mechanical and tribological properties were investigated using X-ray diffraction, scanning electron microscopy (SEM), nano-mechanical testing system, scratch tester and reciprocating tribometer. The results show that micro-blasting significantly reduces the surface roughness and converts the residual tensile stress of Ti(C,N,O) top-layer and Al₂O₃ layer into compressive stress. Affected by the residual compressive stress, the hardness and adhesion strength are increased. More importantly, the friction coefficient is decreased attributed to the decreased surface roughness and improved hardness. Also, the wear resistance of micro-blasted TiN/MT-TiCN/Al₂O₃/TiCNO is superior due to higher hardness of Ti(C,N,O) top-layer, Al₂O₃ layer and adhesion strength of coatings. Especially for the total sliding time of 2 h, the wear volume and wear rate of micro-blasted coatings are 69.4% of as-deposited coatings, because micro-blasting helps to increase the adhesion strength and micro-cracking resistance, which play important roles in the improvement of wear resistance. Micro-blasting has a positive effect on the friction and wear properties of TiN/MT-TiCN/Al₂O₃/TiCNO multilayer coatings since the adverse impact of top-layer thinning is offset.     

TiAlN,TiAlSiN涂层的制备及其切削性能

目的研究TiAlN及TiAlSiN涂层的微观结构及力学性能,以及硬质合金涂层刀具切削SUS304不锈钢的切削性能及磨损行为。方法采用阴极电弧离子镀技术在硬质合金试片及铣刀上分别制备纳微米TiAlN及TiAlSiN涂层。通过X射线荧光测量系统测量涂层的厚度,用扫描电镜(SEM)观察涂层表面形貌,用能谱仪(EDAX)分析涂层元素成分,用X射线衍射(XRD)分析涂层晶相结构,用纳米压痕仪表征涂层硬度,用洛氏硬度计定性测量涂层结合力,通过高速铣削试验探究涂层刀具的切削性能及磨损行为。结果 TiAlN及TiAlSiN涂层的厚度分别为3.32μm和3.35μm,表面致密、光滑,高分辨率(20 000×)下观察到涂层表面有液滴、针孔及凹坑存在。Si元素促进了Ti N(200)晶相的生长,晶粒尺寸减小,硬度增加。TiAlN及TiAlSiN涂层的显微硬度分别为29.6 GPa及37.7 GPa,结合力分别满足VDI-3198工业标准的HF3和HF1等级。在130 m/min的高速切削条件下,TiAlSiN涂层刀具寿命约为未涂层刀具的5倍,TiAlN涂层刀具的1.5倍。结论 Si掺杂制备的TiAlSiN涂层具有高的硬度及良好的抗粘附性,更适用于不锈钢材料的高速切削加工。     

Evaluation offing surfaces with several coatings for friction, wear and scuffing life

Friction and wear of the sliding components in an automobile cause an increase in both fuel consumption and emission. Many engine components involved with sliding contact are all susceptible to scuffing failure at some points during their operating period. Therefore, it is important to evaluate the effects of various surface coatings on the tribological characteristics of the piston ring and cylinder block surface of a diesel engine. Wear and scuffing tests were conducted using a friction and wear measurement of the piston ring and cylinder block in a low friction diesel engine. The frictional forces, wear amounts and cycles to scuffing in the boundary lubricated sliding condition were measured using the reciprocating wear tester. The tester used a piece of the cylinder block as the reciprocating specimen and a segment of the piston ring material as the fixed pin. Several coatings on the ring specimen were used, such as DLC, TiN, Cr-ceramic and TiAlN, in order to improve the tribological characteristics of the ring. The coefficients of friction were monitored during the tests, and the wear volumes of the piston ring surfaces with various coatings were compared. Test results show that the DLC coating exhibits better tribological properties than the other coatings. The graphite structure of this coating is responsible for the low friction and wear of the DLC film. The TiN and DLC coatings show better scuffing resistance than the other coatings. The TiN and Cr-ceramic coated rings show good wear resistance and high friction.     

不同掺杂设计对类金刚石涂层海水环境摩擦学性能的影响

采用UDP650型闭合场非平衡磁控溅射系统在硅片及316不锈钢基底表面制备了不同掺杂设计的类金刚石涂层(DLC、Cr/DLC和WC/DLC),通过SEM、Raman、硬度仪和划痕仪研究了涂层的结构及力学性能,利用多功能摩擦试验机考察了涂层在大气及海水环境下的摩擦学性能。结果表明,Cr或WC掺杂能显著促进DLC涂层的石墨化,同时提高涂层的结合力及韧性。在摩擦磨损试验中,由于海水的润滑作用,3种涂层在海水环境下的摩擦因数及磨损率均低于大气环境。同时,WC/DLC在3种涂层中表现出最佳的摩擦学性能,这取决于其高的石墨化程度,良好的结合力及优异的韧性。     

Wear of PVD Ti/TiN multilayer coatings

The wear characteristics of PVD Ti/TiN multilayer coatings subjected to two-body abrasion and particle erosion have been studied using diamond slurry and silicon carbide particles as abrasive medium and erodant, respectively. The abrasive wear rate of the Ti/TiN multilayer coatings was found to increase with the relative amount of metallic Ti in the coatings. In erosion, the lowest wear rate was recorded for the homogeneous TiN coating. For the Ti/TiN multilayer coatings the erosion rate was found to decrease with an increasing relative amount of metallic Ti in the coatings. It is concluded that the concept of multilayered coatings offers a potent means to tailor the properties of tribological coatings. In particular, demands of different applications can be met by adjusting the relative thickness of metallic Ti in Ti/TiN coatings. The amount of metallic Ti can, for example, be used to control the coating residual stress state. Multilayered Ti/TiN coatings seem promising for combined wear and corrosion protection.     

Friction and wear behavior of the PVD (Zr,Ti)N coated cemented carbide against 40Cr hardened steel

(Zr,Ti)N hard coatings were deposited on WC/TiC/Co cemented carbide by multi arc ion plating. Friction and wear behavior of the (Zr,Ti)N coatings against 40Cr hardened steel were evaluated using a ball-on-disk tribometer. The friction coefficients and wear rates were measured with varying applied loads and sliding speeds. The results showed that the friction coefficient increased with the increase of the applied load, and decreased with the increase of sliding speed. The wear rate decreased with both increasing applied load and sliding speed. The wear mechanism of the coatings at low friction loads was mild abrasive wear and flake while brittle fracture and flake at high applied loads. The wear mode of the (Zr,Ti)N coatings changed from adhesive wear and brittle fracture to mild abrasive wear as the sliding speed increased. The EGC coating which presents a graded distribution of coefficient of thermal expansion shows best wear resistant properties, in particular at high load and sliding speed conditions. Cracks, flakes and delamination fracture of the coatings were observed. The major failure mechanisms of the coatings are flaking and delamination.