等离子渗氮与喷丸强化复合改进钛合金抗微动损伤性能

利用直流脉冲等离子电源装置对Ti6A14V钛合金表面渗氮处理,研究了渗氮层的相组成、硬度分布、韧度及摩擦学性能,采用喷丸形变强化(SP)对渗氮层进行后处理,以达到联合提高钛合金微动疲劳(FF)抗力的目的.研究结果表明:脉冲电源等离子技术可在钛合金表面获得由TiN、Ti2N、Ti2A1N等相组成的渗氮层,该改性层能够显著地提高钛合金常规磨损和微动磨损(FW)抗力,但降低了基材的FF抗力.渗氮层的减摩和抗磨性能与SP引入的表面残余压应力协同作用,使钛合金FF抗力超过了SP单独作用.提高渗氮层韧度对改善钛合金FF和FW性能均十分重要.     

Ti6Al4V合金表面Ti(C,N)改性层的摩擦性能

利用双层辉光等离子表面冶金技术,以石墨为源极,Ti6Al4V为阴极,一定比例的氮气和氩气为载气,在其表面形成Ti(C,N)改性层。观察分析了改性层的成分、显微组织及相结构,评价了其纳米硬度和室温干滑动磨损条件下的摩擦磨损性能。结果表明:改性层主要组成相为Ti(C0.3N0.7);碳、氮元素分布由表及里呈梯度分布;改性层纳米硬度高达41 GPa,较基体明显提高;在室温干摩擦磨损条件下,改性层与基体相比,摩擦因数由0.45降低到0.28,比磨损率也大大下降,表现出优异的耐磨减摩性能。     

Tribological properties of 2024 aluminum alloy plasma-based ion implanted with nitrogen then titanium

1　INTRODUCTIONOwingtolowdensityandhighspecificstrength ,aluminumanditsalloysareextensivelyusedinmanyfields ,especiallyinaviationandspaceindustry .Butlowhardnessandlowwearresistanceoftenlimittheirengineeringapplications .Surfacemodificationforalu minumanditsalloysbyionimplantationoffersthepossibilityofwideningtheirapplicationswherehighwearresistanceandlowdensityarerequired[15] .Sincenitrogenionisconvenienttoobtainandeasytocontrol,andAlNhasexcellentmechanicalproperties ,nitrogenionimplant…     

Wear and transfer characteristics of carbon fiber reinforced polymer composites under water lubrication

The tribological characteristics of carbon fiber reinforced polymer composites under distilled-water-lubricated-sliding and dry-sliding against stainless steel were comparatively investigated. Scanning electron microscopy (SEM) was utilized to examine composite microstructures and modes of failure. The typical chemical states of elements of the transfer film on the stainless steel were examined with X-ray photoelectron spectroscopy (XPS). Wear testing and SEM analysis show that all the composites hold the lowered friction coefficient and show much better wear resistance under water lubricated sliding against stainless steel than those under dry sliding. The wear of composites is characterized by plastic deformation, scuffing, micro cracking, and spalling under both dry-sliding and water lubricated conditions. Plastic deformation, scuffing, micro cracking, and spalling, however, are significantly abated under water-lubricated condition. XPS analysis conforms that none of the materials produces transfer films on the stainless steel counterface with the type familiar from dry sliding, and the transfer of composites onto the counterpart ring surface is significantly hindered while the oxidation of the stainless steel is speeded under water lubrication. The composites hinder transfer onto the steel surface and the boundary lubricating action of water accounts for the much smaller wear rate under water lubrication compared with that under dry sliding. The easier transfer of the composite onto the counterpart steel surface accounts for the larger wear rate of the polymer composite under dry sliding.     

Ceramic Conversion Treatment of Titanium Aluminide for Improved Tribological Properties

GAMMA based titanium aluminides have greatpotential for high temperature applications,such as jetengine components and exhaust valves in car engines,owing to their high specific strength,high stiffness andgood creep resistance at elevated temperatures[1,2,3].For some of the proposed applications,e.g.,valves in acar engine involving tribo-contact,tribologicalproperties could be thus one of the crucial factors indetermining the life and performance of a titaniumaluminide part.A few studies have…     

Effects of Micro-Arc Oxidation of Ti6Al4V Alloy on Adhesion Property to Electroless Ni-P-ZrO2 Composite Platings and Their Wear Resistance

在Ti6Al4V合金微弧氧化膜表面制备Ni-P-ZrO2化学复合镀层,微弧氧化处理时间分别为15、30、60、90 min。采用扫描电镜/能谱仪、划痕试验、热震试验、显微硬度计和球盘式摩擦磨损试验机研究了微弧氧化膜结构对Ni-P-ZrO2化学复合镀层的结合性能与摩擦性能的影响。结果表明：随着微弧氧化时间的增加,复合镀层的结合性能显著提高,原因是微弧氧化膜的多孔性结构及其机械锁合效应。与Ti6Al4V合金相比,微弧氧化+化学复合镀处理后的试样硬度和耐磨性显著提高,Ti6Al4V合金表现为是严重的黏着磨损,而Ni-P-ZrO2复合镀层以磨砺磨损为主     

钛合金表面大气压等离子体枪制备类金刚石薄膜

在大气下,采用大气压介质阻挡放电(DBD)等离子体枪在低温下(350℃),以甲烷为单体,氩气为工作气体,在Ti6Al4V钛合金表面制备一层类金刚石薄膜(DLC),以期改善钛合金表面摩擦学性能。利用激光拉曼(Raman)光谱和X射线光电子能谱(XPS)分析了所制备DLC薄膜的结构;利用扫描电子显微镜(SEM)观察DLC薄膜的表面形貌;利用划痕仪测量了DLC薄膜与基体的结合力;利用球-盘摩擦磨损实验仪对DLC薄膜的耐磨性能进行了研究。结果表明:在本实验工艺条件下沉积的类金刚石薄膜厚度约为1.0μm,薄膜均匀且致密,表面粗糙度Ra为13.23nm。类金刚石薄膜与基体结合力的临界载荷达到31.0N。DLC薄膜具有优良的减摩性,Ti6Al4V表面沉积DLC薄膜后摩擦系数为0.15,较Ti6Al4V基体的摩擦系数0.50明显减小,耐磨性能得到提高。     

Ti6Al4V合金干滑动磨损过程中摩擦层及摩擦氧化物的作用

目的分析Ti6Al4V合金在不同滑动速度下的干滑动磨损行为及磨损特征,研究钛合金的磨损机理,并探讨干滑动磨损过程中摩擦层及摩擦氧化物的作用。方法采用销盘式摩擦磨损试验机,对Ti6Al4V合金在不同滑动速度下进行干滑动磨损实验。采用磨损率和摩擦系数表征钛合金的磨损行为,采用SEM、EDS及XRD分析磨损表面及摩擦层的形貌及成分,采用数字显微硬度仪表征摩擦层的力学性能。结果滑动速度在0.5～4 m/s范围内变化,Ti6Al4V合金的磨损率发生显著变化,尤其是在高载条件下。0.5～1.5 m/s速度范围内,磨损率较低,2.68m/s速度下,磨损率达到最高值,4m/s速度下,磨损率达到最低值。0.75m/s速度下,粘着磨损和磨粒磨损为主要磨损机理,氧化磨损为次要磨损机理;2.68 m/s和4 m/s速度下的磨损机理分别为剥层磨损和氧化轻微磨损。2.68m/s速度下的高磨损率与硬度较低的无氧化物摩擦层对应,而4 m/s速度下的低磨损率与高硬度的多氧化物摩擦层对应。结论试验条件改变,Ti6Al4V合金的磨损行为及磨损机理发生变化。不同试验条件下的磨损行为与不同的摩擦层特征相对应,当摩擦层中包含一定量的摩擦氧化物时,这种陶瓷性的摩擦层具有比基体更高的硬度,能有效保护基体,降低磨损率。     

Structure and tribological properties of modified layer on 2024 aluminum alloy by plasma-based ion implantation with nitrogen/titanium/carbon

1　INTRODUCTIONGoodmachinability ,lowdensityandhighspecif icstrengthmakealuminumanditsalloysextensivelybeusedinmanyindustries ,especiallyinaviationandspaceflightindustry .Howeverlowsurfacehardnessandlowwearresistanceoftenlimittheirengineeringapplications .Nitrogenionimplantationintoalu minumanditsalloysoffersthepossibilityofapplica tionswherebothhighwearresistanceandlowdensityarerequired[15] .Moreover ,ourpreviousinvestiga tion[6 ,7] presentedthatwhenaluminumalloywasim plantedwithnitrogen…     

Ti13Nb13Zr 合金离子氮化层的摩擦磨损性能研究

目的提高医用钛合金的耐磨损性能。方法应用等离子渗氮技术在Ti13Nb13Zr基材上制备改性层,并对改性层组织、成分及硬度进行测试。利用往复磨损试验机研究改性层在干摩擦条件下的摩擦磨损性能,并与未处理的基材进行对比。结果 Ti13Nb13Zr合金表面经渗氮后形成致密均匀的改性层,硬度高达1110HV0.025,改性层的磨损体积约为基材的1/23。结论等离子渗氮技术有效地改善了Ti13Nb13Zr合金的摩擦磨损性能。     

The Tribological Performance of Surface Treated Ti6A14V as Sliding Against Si<Subscript>3</Subscript>N<Subscript>4</Subscript> Ball and 316L Stainless Steel Cylinder

Closed field unbalanced magnetron sputtering was used to deposit diamond-like carbon (Ti-C:H) coatings on Ti6Al4V alloy and gas nitrided Ti6Al4V alloy. Four different specimens were prepared, namely untreated Ti6Al4V alloy (Ti6Al4V), gas nitrided Ti6Al4V alloy (N-Ti6Al4V), Ti-C:H-coated Ti6Al4V alloy (Ti-C:H/Ti6Al4V) and Ti-C:H-coated gas nitrided Ti6Al4V alloy (Ti-C:H/N-Ti6Al4V). The tribological properties of the four specimens were evaluated using a reciprocating wear tester sliding against a Si₃N₄ ball (point contact mode) and 316L stainless steel cylinder (line contact mode). The wear tests were performed in a 0.89 wt.% NaCl solution. The results showed that the nitriding treatment increased the surface roughness and hardness of the Ti6Al4V alloy and improved the wear resistance as a result. In addition, the Ti-C:H coating also improved the tribological performance of Ti6Al4V. For example, compared to the untreated Ti6Al4V sample, the Ti-C:H coating reduced the wear depth and friction coefficient by 340 times and 10 times, respectively, in the point contact wear mode, and 151 times and 9 times, respectively, in the line contact wear mode. It is thus inferred that diamond-like carbon coatings are of significant benefit in extending the service life of artificial biomedical implants.     

Wear properties of nonhydrogenated,hydrogenated,and dehydrogenated Ti6A14V alloy

Wear properties of the nonhydrogenated,hydrogenated 0.5 wt% and dehydrogenated Ti6 A14 V alloys were studied through dry sliding wear tests using an M-200 type pin-on-disk wear testing machine in ambient air at room temperature to reveal the effects of hydrogen on wear properties of Ti6 A14 V alloy. Morphology and chemical element of worn surface were investigated by means of scanning electron microscope(SEM) and energy dispersive spectroscopy(EDS). Results show that hydrogen decreases the wear resistance of Ti6 A14 V alloy. Wear rate of the Ti6 A14 V alloy increases after hydrogenation. Wear rate increases by 244.3 % when 0.5 wt% hydrogen is introduced into a Ti6 A14 V alloy. Wear rate of the dehydrogenated Ti6 A14 V alloy recovers. Wear mechanisms of the nonhydrogenated, hydrogenated, and dehydrogenated Ti6 A14 V alloys are determined. The nonhydrogenated Ti6 A14 V alloy is controlled by oxidative wear. The hydrogenated Ti6 A14 V alloy is dominated by abrasive wear. Wear mechanism of the dehydrogenated Ti6 A14 V alloys is a mixture of oxidative wear and abrasive wear.     

Surface engineering techniques used for improving the mechanical and tribological properties of the Ti6A14V alloy

The microstructure, mechanical and tribological properties of composite intermetallic layers of the Ti-Al system were investigated. The layers on the two-phase (α + β) Ti6Al4V titanium alloy were obtained using the hybrid method, which consist of two stages. First, the titanium alloy was covered with aluminum layer by magnetron sputtering. In the second stage, coated specimens were treated under glow discharge conditions. The surface treatment makes it possible to obtain the diffusional composite layers which considerably improve the mechanical and wear resistance properties of the material. These properties cannot be achieved using simple methods of surface engineering. The chemical and phase composition of the composite intermetallic layers was investigated. It has been shown that the hybrid method significantly increases the hardness and wear resistance of the titanium alloy and can widen the range of application of the material. Because of the diffusional character of the intermetallic layers they possess good adhesion to the titanium substrate.     

激光熔覆 CBN 膜层的形态特征及性能研究

目的提高钛合金的表面硬度和耐磨性能。方法采用激光熔覆工艺,在TC11钛合金表面制备80%CBN+20%Ti(均为质量分数)熔覆层,分析熔覆层的显微组织、硬度和耐磨性能。结果熔覆层的显微组织沿层深方向分为熔覆区、结合区和过渡区三个区域,区域之间没有明显的裂纹和断层。CBN膜层的显微硬度最高达到950HV0.2,耐磨性比纯Ti熔覆层提高了近14倍。结论在钛合金表面激光熔覆CBN抗磨涂层,不仅耐磨损性能良好,而且表面硬度得到了有效提高。     

钛合金Ti6Al4V表面渗钼层的摩擦磨损性能

利用双层辉光离子渗金属技术在钛合金Ti6Al4V表面进行合金化，形成均匀、致密、厚度为9．4μm的钛钼合金渗层。表面硬度提高3倍左右，达到1050Hκ。采用球盘磨损试验机考察了钛合金Ti6Al4V表面渗钼层和Ti6Al4V钛合金的摩擦性能，得出该合金表面渗Mo后虽然摩擦因数略微增大，但耐磨性提高100余倍；通过对磨损形貌的分析可知，表面渗Mo合金层磨损机制主要表现为粘着及少量微切削。     

钛合金表面辉光离子渗Mo合金化层在航空煤油环境中的摩擦学行为(英文)

为改善钛合金在航空煤油中的摩擦学性能,采用辉光离子渗技术在Ti6Al4V合金表面制备Mo合金化层。分析合金化层的表面形貌和微观结构,测试合金化层的显微硬度和元素沿层深的分布,对比研究钛合金基体、渗Mo合金化层和5CrMnMo工具钢在航空煤油中分别与GCr15钢及QSn4-3铜合金配副对磨时的耐磨性能,并探讨渗Mo合金化层的表面粗糙度对摩擦磨损行为的影响。结果表明:经表面抛光处理后,钛合金表面辉光离子渗Mo合金化层不仅显著降低了钛合金的摩擦因数,而且有效增强了摩擦配副的耐磨性。渗Mo合金化层的摩擦性能优于5CrMnMo工具钢。实验还发现铜合金配副的磨损体积损失与Mo合金化层的表面粗糙度成正比,这主要是由合金化层与配副表面之间微凸体的磨粒磨损作用决定的。     

TC21钛合金表面无氢渗碳层耐磨性分析

将经过预处理的TC21钛合金试样置入真空渗碳炉中进行渗碳。分别用X射线衍射(XRD)、扫描电子显微镜(SEM)及显微维氏(HV)硬度仪、摩擦磨损试验机,对渗碳层的物相结构、组织形貌、硬度和耐磨性进行分析。结果表明:经渗碳处理后,通过渗层组织可判定没有氢化物,XRD未检测发现氢化物及含H相,出现了Ti C等碳化物相,表面硬度提高了2.66倍。渗碳前Ti/Ti对磨的摩擦系数约为0.6,渗碳后Ti C/Ti C的摩擦系数约为0.23,渗碳体与原始表面的摩擦系数介于二者之间。TC21钛合金对磨两方经渗碳处理,改善了摩擦性能;如Ti/Ti部件对磨时,渗碳方可提高耐磨性,非渗碳件在与渗碳件对磨中,加剧了非渗碳件的磨损。渗碳也改变了TC21钛合金部件之间的摩擦状态,TC21基体由Ti基/Ti球之间的粘着磨损变为Ti基/Ti C球磨粒磨损+剥层磨损。     

钛合金双层辉光离子无氢碳氮共渗摩擦性能研究

利用双层辉光离子渗金属原理改善钛合金Ti6Al4V的耐摩擦性。使用蜂窝状高纯度固体石墨作为源极，钛合金Ti6Al4V做阴极，一定比例的氩气、氮气作为载气。依靠辉光放电空心阴极效应，溅射出原子、离子状的碳元素，碳、氮元素混合形成等离子体，靠阴极负偏压把碳、氮吸引到Ti6Al4V的表面，依靠轰击和扩散在Ti6Al4V材料表面形成具有特殊物理、化学性能的合金层。X射线衍射检测显示渗层内形成了包含TiC，TiN的硬度相；辉光放电光谱（GDS）检测结果显示，在渗层内碳、氮元素分们呈梯度形式；硬度测试显示渗层硬度由表及里呈现梯度下降，表面硬度提高两倍以上；摩擦磨损检测表明Ti6Al4V材料经无氢碳氮共渗处理后，其粘着现象明显降低，摩擦系数降低一半多，耐磨性大大提高。     

钛合金圆环工件表面合金化及其滚动摩擦性能研究

采用等离子表面合金化技术在Ti6Al4V合金圆环工件表面制备Mo渗镀改性层,将其与未渗Mo处理的Ti6Al4V合金在模拟实际工况条件下进行油润滑的滚动摩擦对比试验,比较二者的磨损情况,并分析磨损机理。结果表明,Ti6Al4V合金表面进行渗Mo处理后,形成了均匀、致密且高硬度的Mo基改性层。Ti6Al4V合金表面渗Mo后,硬度由渗层到基体呈梯度分布。滚动摩擦试验表明,渗Mo处理后表面无减摩效果,但磨损量大大减小,耐磨性得到有效改进。通过对磨损形貌的分析可知,表面渗Mo处理后磨损机理主要以磨粒磨损为主,而基材是磨粒磨损和粘着磨损。     

钛合金辉光离子渗硫与摩擦学特性研究

对Ti-6Al-4V合金表面进行辉光离子渗硫处理后的显微组织、摩擦学特性进行了研究.结果表明:合金经离子渗硫处理后,渗层主要由TiS2、TiS、TiS3、Ti2S等硫化物组成;对处理前后试样的摩擦学性能研究显示,渗硫后试样在干摩擦纯滑动的情况下表现出良好的减摩性能,并对减摩机理进行了探讨.