无氢DLC涂层的摩擦学性能

为了探究轮胎模具无氢类金刚石(DLC)涂层的摩擦学特性,增强轮胎模具的易脱模、防粘、自清洁性能以及提高轮胎质量与服役寿命,以轮胎模具常用的35钢为基体,利用电弧离子镀在基体试样上制备无氢DLC涂层,对涂层Raman光谱、表面粗糙度、表面微观形貌、纳米硬度、结合力和摩擦系数进行了分析,着重研究涂层摩擦前后表面微观形貌的变化以及摩擦磨损机理。结果表明:通过改变表面粗糙度可以有效降低涂层的摩擦系数,涂层摩擦系数随粗糙度减小而显著降低;在140℃高温条件下,摩擦系数最小低至0.363 4,且涂层纳米硬度可达32.45 GPa,弹性模量高达348.94 GPa。无氢DLC涂层完全满足轮胎模具减摩耐磨和自清洁性的使用要求,为制造高性能轮胎模具提供了一种可行的工艺选择。     

轮胎模具DLC涂层的制备及性能

为探究高性能轮胎模具类金刚石(DLC)涂层的应用前景,提高模具花纹块内表面的疏水性及耐磨减摩性,采用等离子体增强化学气相沉积法在35钢基体上制备DLC涂层,并对所制备的DLC涂层的表面形貌、粗糙度、疏水性、表面元素组成、纳米硬度、摩擦系数等关键指标进行了测定.结果表明:DLC涂层具有优良的表面完整性,水接触角可达19.62°,乙醇接触角达20.37°,纳米硬度可达19.62 GPa,摩擦系数低至0.405 8,DLC涂层有望替代Teflon涂层,用于高性能轮胎模具.     

轮胎模具F-DLC涂层的制备及性能

为探究高性能轮胎模具F-DLC涂层的应用前景,提高轮胎模具内表面的疏水性、耐磨减摩性,采用等离子体增强化学气相沉积法在35钢基体上制备F-DLC涂层.利用Raman光谱仪与原子力显微镜对其结构与表面形貌进行了表征;利用接触角测量仪测量涂层的疏水角;另外,利用端面摩擦磨损试验机对涂层摩擦磨损性能进行了研究.结果表明:涂层内应力小、表面平整、颗粒均匀;涂层疏水角为98.54°,疏水性好;在140℃的试验温度下,摩擦系数低至0.271;纳米硬度为15.85 GPa,弹性模量为110.5 GPa.F-DLC涂层优异的性能可以有效提高轮胎模具脱模、抗粘胶的工作性能,为制造高质量的轮胎模具提供了一种可行的方案.     

DLC、Teflon涂层形貌及性能参数对比研究

为探究类金刚石(DLC)涂层替代Teflon涂层应用于轮胎模具的可能性,解决Teflon涂层耐磨性差、寿命短、清洗复杂的问题,对DLC与Teflon涂层的形貌(表面形貌、断面结构)及性能参数(疏水性、结合力、硬度、坯胎-涂层摩擦系数)进行对比试验。结果表明,在疏水性与摩擦系数方面,DLC涂层与Teflon涂层基本相当;在表面硬度与其他方面,DLC涂层优于Teflon涂层。从对比试验结果而言,DLC涂层替代Teflon涂层应用于轮胎模具具有可行性。     

轮胎模具DLC涂层应用的可行性分析

为了探究类金刚石(DLC)涂层在轮胎模具上应用的可行性,以35钢为基体,采用等离子辅助增强化学气相沉积(PECVD)的方法分别制备出了含氢类金刚石(DLC)涂层和氟化类金刚石(F-DLC)涂层,并对涂层表面形貌、Raman光谱、表面粗糙度、结合强度、力学性能、摩擦磨损性能进行了研究分析。结果表明:所制备的含氢DLC涂层和F-DLC涂层表面粗糙度分别为53.2 nm和54.6 nm,表面光滑,致密性好;涂层接触角分别为81.2°和98.5°,符合脱模要求;纳米硬度分别为23.9 GPa和14.3 GPa,弹性模量分别为177.0 GPa和118.5 GPa,拥有较高的结合强度和力学性能;在140℃下进行摩擦磨损试验时的摩擦系数分别为0.448 7和0.263 1,磨损不明显,具有良好的抗磨减摩特性。采用该工艺方法来制备轮胎模具DLC涂层具有应用的可行性。     

面向石墨模具精密加工的金刚石涂层结构及性能

金刚石涂层具有接近天然金刚石的超高硬度及耐磨性,被认为是精密加工石墨模具的理想刀具涂层材料.金刚石涂层与刀具基体间的结合力及涂层表面状态是高速干式切削加工质量及效率的关键,金刚石涂层前处理过程控制及涂层工艺是影响金刚石涂层刀具综合性能的重要因素.本工作基于热丝化学气相沉积技术,采用酸-碱-酸三步法对硬质合金材料进行前处理,在涂层沉积过程中采用大气流量及高炉压沉积工艺在刀具基体表面沉积金刚石涂层.采用扫描电镜(SEM)、原子力显微镜(AFM)、拉曼光谱(Raman)、X射线衍射光谱(XRD)对涂层微观结构及物相结构进行分析表征,利用纳米压痕仪对金刚石涂层硬度进行测试,利用喷砂试验测试金刚石涂层的抗冲刷性能,利 用石墨模具切削试验表征金刚石涂层刀具的切削性能.结果表明,金刚石涂层呈典型八面体结构,涂层与基体紧密结合、无明显孔隙,金刚石涂层刀具表面粗糙度为157 nm,sp3键含量大于98％,(涂层硬度大于90 GPa),涂层沿(111)面择优生长,抗冲刷时间大于150 s(0.5 MPa,120目),涂层刀具高速切削石墨模具2 h后,被加工面表面粗糙度小于1 μm,达到进口刀具水平.切削完成后刀具前刀面出现少量崩缺,前刀面磨损是此类刀具加工石墨模具的主要磨损形式.     

TiN与DLC涂层在船用低速柴油机柱塞上的应用研究

为提高船用低速柴油机柱塞的耐磨性和柱塞偶件使用寿命,采用离子镀技术与多弧磁控耦合镀膜技术分别在柱塞上涂覆了TiN涂层和DLC涂层。利用扫描电镜（SEM）、轮廓仪和X射线衍射仪（XRD）技术表征了TiN与DLC涂层的微观形貌、表面粗糙度及物相组成,采用纳米压痕仪检测了TiN与DLC涂层的纳米硬度及弹性模量;运用划痕法和压痕法测试了TiN和DLC涂层的结合力,通过往复磨损试验考察了这2种涂层在空气中与在重柴油环境下的摩擦系数,同时结合光学显微镜定性评判TiN和DLC涂层磨损程度,通过台架试验评价了TiN涂层与DLC涂层柱塞的实际磨损情况。结果表明：这2种涂层晶体生长良好、结构连续致密,均未出现分层、开裂及剥离的现象,DLC涂层相对光滑,粗糙度R_a为0.10μm,而TiN涂层R_a为0.16μm; DLC涂层表面纳米硬度、弹性模量及泊松比均高于TiN涂层;无论在空气中还是重油环境下,TiN涂层摩擦系数均高于DLC涂层,耐磨性低于DLC涂层;台架试验后TiN涂层柱塞表面出现比较明显的平行状沟槽磨痕,而且整体磨损比较严重,而DLC涂层柱塞表面的磨痕非常窄...     

溶胶-凝胶法超疏水含氟硅聚氨酯丙烯酸酯/SiO2杂化涂层的制备

以正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES)为前驱体,在含氟硅聚氨酯丙烯酸酯(FSiPUA)复合乳液中采用溶胶-凝胶法制备了超疏水杂化涂层。考察了MTES/TEOS的摩尔比和FSiPUA复合乳液用量等对涂层表面粗糙度、疏水性、成膜性等表面性能的影响。通过扫描电镜和接触角仪表征了涂层的微观结构及疏水性,利用马尔文粒度分析仪和傅里叶红外光谱仪分析了二氧化硅(SiO2)的平均粒径和化学结构。结果表明,随着MTES/TEOS摩尔比增加,杂化涂层的表面粗糙度逐渐下降,疏水性先增大后减小;随着FSiPUA复合乳液用量增加,涂层的成膜性逐渐变好;当(TEOS+MTES)∶C2H5OH∶NH3·H2O∶AMP-95的摩尔比为1∶6.67∶1.83∶0.24,MTES/TEOS摩尔比值为5,FSiPUA复合乳液用量为20%时,涂层具有超疏水特性,其水接触角(WCA)和滚动角(SA)分别为161.5°和2.8°,涂层表面对水滴具有优异的不粘附性。     

化学镀铜前碳纤维预处理的研究

碳纤维具有疏水性和表面惰性,很难直接镀铜.为此,研究了碳纤维表面的预处理工艺、条件等技术参数.结果表明:高温灼烧除胶、过硫酸铵氧化、氯化银活化较好地改善了碳纤维的疏水性,大大提高了碳纤维表面的粗糙度,使碳纤维表面具有了催化活性.预处理后的碳纤维进行化学镀铜,其镀层光亮、均匀、致密,与基体的结合力较好.     

飞机发动机风扇叶片CuNiIn涂层等离子喷涂的工艺优化

为了给国内航空发动机风扇叶片Cu Ni In涂层制备提供相关技术支持,利用等离子喷涂技术在Ti6Al4V基体材料上制备Cu Ni In涂层,观察涂层微观结构,分析涂层孔隙率、界面污染物等,研究喷涂功率、喷涂距离及基体表面粗糙度对涂层结合强度、显微硬度等的影响。结果表明:喷涂功率的增加会导致Cu Ni In涂层显微硬度增加,结合强度降低;喷涂距离增加,涂层显微硬度和结合强度都呈现先增后减的趋势;基体表面粗糙度增加,涂层结合强度增加,但粉末沉积率降低;优化工艺为喷涂功率32.3 k W,喷涂距离85 mm,采用36目白刚玉喷砂(基体表面粗糙度6.3μm);优化工艺制备的涂层结合强度达到45.83 MPa,显微硬度达到159.2 HV,孔隙率为0.578%,可为国内风扇叶片Cu Ni In涂层制备提供相关技术支持。     

Failure of Nickel Coating on a Copper Mold of a Slab Caster

Copper molds are critical components in the continuous casting of steel. Surface condition of the mold directly affects product quality, and premature failure/low wear life affects the output of the continuous casting plant. This paper presents the failure analysis of a nickel coating on a copper plate during a plant trial using in situ ultrasonic testing for coating thickness evaluation and in situ testing to confirm the loss of coating. The failure analysis indicated maximum coating wear near the bottom corners of the mold. More wear was found on the wide end face compared with that observed on the narrow face. On top portion of the mold, wear was almost negligible. Based on the wear profile obtained during trial, it was recommended that the coating on the bottom portion of the mold have a higher hardness to improve mold life.     

非平衡磁控溅射技术制备用于红外减反射的无氢碳膜

红外减反射保护膜具有特定的厚度要求,如能进一步减小无氢类金刚石膜(DLC)的光学吸收,就能使其在较大厚度时不过分损失光通量而得以广泛应用.从这点来讲,无氢类金刚石膜是一种极具开发潜力的材料.本文采用非平衡磁控溅射技术(UBMS)制备了无氢类金刚石膜,并研究了其厚度均匀性.研究结果表明:该非平衡磁控溅射装置有能力获得大于φ150 mm的均匀性范围.对DLC膜红外透射谱的分析表明,分别在Si和Ge基底表面单面制备的DLC薄膜,其峰值透射率在波数2983/cm时分别为68.83%和63.05%,这一结果接近无吸收碳材料理论上所能达到的值.同时,在5000到800/cm范围内,未发现明显的吸收峰.这些优良的光学特性表明,采用非平衡磁控溅射技术制备的无氢DLC膜可以作为窗口的红外增透保护膜使用.     

MAO层厚度对MAO/DLC复合膜层力学性能与摩擦学特性的影响

借助直流脉冲微弧氧化(MAO)电源,采用恒压模式在AZ80镁合金表面制备四种不同厚度MgO陶瓷层,并以此为基,采用离子束复合磁控溅射技术沉积类金刚石碳(DLC)膜,对比研究了四种膜层体系(MAO-1min/DLC、MAO-3min/DLC、MAO-5min/DLC及MAO-10min/DLC)的表面结构特征、力学性能以及摩擦学性能差异。结果表明:随MAO层厚度增加,复合膜层表面微孔的孔径增大,表面粗糙度增加,且表层DLC膜具有颗粒特征,表现为MAO-3min/DLC及MAO-10min/DLC复合膜层具有较高的纳米硬度和弹性模量,且在磨损过程中对应的摩擦系数与磨痕宽度较小,其抗磨损性能优异;各复合膜层体系在磨损过程中摩擦系数均有波动,产生高温氧化,磨痕表面形成了Fe的转移层;MAO层可提高基体对DLC膜的支撑强度,表层DLC膜对磨损界面具有的润滑作用是复合膜层改善镁基体抗磨损性能之原因所在。     

真空弧源沉积类金刚石薄膜及其性能研究

采用真空弧源沉积技术在钛合金及Si(100)表面合成DLC薄膜．通入不同的氩气．控制DLC薄膜中的SP3／SP2比值。研究表明，薄膜硬度可达96GPa．随着氩气流量的增加，薄膜的硬度先增加．后有明显降低。随着氩气流量的增加，类金刚石薄膜中．SP2键增加，SP3键减少，而血液相容性明显提高。DLC薄膜具有优异的耐磨性，摩擦系数低，与钛合金基体结合牢固。     

Characterization of the Diamond—like Carbon based Functionally Gradient Film

Diamond-like carbon coatings have been used as solid lubricating coatings in vacuum technology for their good physical and chemical properties. In this paper, the hybrid technique of unbalanced magnetron sputtering and plasma immersion ion implantation (Pill) was adopted to fabricate diamond-like carbon-based functionally gradient film, N/TiN/Ti(N,C)/DLC, on the 304 stainless steel substrate. The film was characterized by using Raman spectroscopy and glancing X-ray diffraction (GXRD), and the topography and surface roughness of the film was observed using AFM. The mechanical properties of the film were evaluated by nano-indentation. The results showed that the surface roughness of the film was approximately 0.732 nm. The hardness and elastic modulus, fracture toughness and interfacial fracture toughness of N/TiN/Ti(N,C)/DLC functionally gradient film were about 19.84 GPa, 190.03 GPa, 3.75 MRa.m1/2 and 5.68 MPa-m1/2, respectively. Compared with that of DLC monolayer and C/TiC/DLC multilayer, this DLC grad     

高速硫酸盐镀锌工艺及镀层性能

在高碳钢丝的高速硫酸盐镀锌电镀槽液中,采用硫锌-75作添加剂,以提高电流密度上限、电流效率和镀层质量.SEM、X射线衍射的试验结果表明:镀层结晶细腻,晶面取向优化,镀层柔软,富有延展性.生产实践表明:镀锌钢丝在拉拔过程中的锌层损耗、模具损耗和生产成本降低,产品质量得到了提高.     

Effect of thick DLC coating on fatigue behaviour of magnesium alloy in laboratory air and demineralised water

Rotating bending fatigue tests have been performed using Diamond‐like carbon (DLC) coated specimens of a wrought magnesium alloy, AZ80A, in laboratory air and demineralised water and the effect of DLC coating on fatigue and corrosion fatigue behaviour was studied. Three film thicknesses of 3.5 μm, 13 μm, and 25 μm (two‐layer film) were evaluated and particular attention was paid to the role of thick DLC coating. In laboratory air, the fatigue strengths of the DLC‐coated specimens were higher than that of the substrate specimen and increased with increasing film thickness. This was because hard DLC coating with good adhesion suppressed the crack initiation due to cracking of inclusions or cyclic slip deformation on the substrate surface. In demineralised water, the fatigue strength of the 3.5‐μm DLC‐coated specimen was the same as that of the substrate specimen due to the penetration of the water through pre‐existing film defects, while the 13‐μm and 25‐μm DLC‐coated specimens showed increased corrosion fatigue strength with increasing film thickness and also exhibited nearly the same fatigue strength as in laboratory air except for a few premature failed specimens, indicating a potential of thick DLC coating or two‐layer coating for complete improvement of corrosion fatigue strength in aqueous environments.     

The influence of DLC coating on the mechanical and frictional properties of unpeened and peened Cu-based bimetal under dry sliding conditions

In this study, the influence of a combination of high-frequency ultrasonic peening (HFUP) technique and diamond-like carbon (DLC) coating on the mechanical and frictional properties of Cu-based alloy sintered on steel by a powder metallurgy (P/M) technique was investigated. The frictional behavior of the Cu-based alloy specimens was assessed using a Schwingung Reibung Verschleiss (SRV) pin-on-disk tribometer sliding against a Cr-plated bearing steel pin under dry sliding conditions. The purpose of this study is to develop a thin wear resistant layer for Cu-based alloy and to extend its application in the automotive industry. Results showed that the over-coated DLC coating deposited onto a peened Cu-based alloy specimen had higher mechanical and lower frictional properties compared to that of the over-coated DLC coating deposited onto an unpeened Cu-based alloy specimen, which may be ascribed to the undulated microstructure caused by HFUP technique resulting in good adhesion. It was revealed that the deposited DLC coating was beneficial for improving the mechanical and frictional properties of Cu-based alloy. Hence, it is expected that the results of this investigation can be applied to improve the frictional behavior of an internal combustion engine (ICE) components which are made of bimetals (sintered Cu-based alloy on a steel back).