高功率脉冲和脉冲直流磁控共溅射CrAlN薄膜的研究

目的通过掺杂适量Al元素来固溶强化Cr N薄膜,从而提高薄膜的抗氧化性能和热稳定性。方法采用高功率脉冲磁控溅射和脉冲直流磁控溅射复合镀膜技术制备了Cr Al N薄膜,利用XRD、纳米压痕仪、应力仪、摩擦磨损试验机系统地研究了不同基体偏压对CrAlN涂层结构和力学性能的影响。结果所有CrAlN涂层均以fcc-(Cr,Al)N相为主,且随着基体偏压的增加,沿(111)晶面生长的衍射峰逐渐减弱,并向小角度偏移;薄膜压应力显著增加,最大值为-2.68GPa;薄膜硬度先上升后下降,在基体偏压为-30V时,硬度达到最大值22.3 GPa;H/E值和H~3/E~(*2)值随着基体偏压的增加,近似线性增大,当偏压为-120 V时,均达最大值0.11、0.21 GPa,同时摩擦系数和磨损率逐渐减小。结论当基体偏压为-120 V时,CrAlN薄膜具有最佳的耐磨性能,H/E和H~3/E~(*2)在一定程度上可评价涂层的耐磨性。     

基底偏压对磁控溅射TiAlSiN涂层微观结构、力学性能及摩擦学性能的影响

采用直流非平衡磁控溅射方法在M42高速钢表面沉积Ti/TiN/TiAlSiN多层薄膜,研究基底偏压对TiAlSiN的晶体结构、微观组织、力学及摩擦学性能的影响。结果表明:基体负偏压从40 V增加到80 V,TiAlSiN由致密的粗大柱状晶向致密纤维状细晶过渡、晶粒宽度由180 nm减小至60 nm;当负偏压大于60 V时,TiAlSiN层由fcc TiN+fcc AlN双相结构转变为fcc TiAlN单相结构;涂层硬度和弹性模量随偏压增大呈现上升趋势,当负偏压为80 V时,涂层的硬度和弹性模量分别为34.1 GPa和378 GPa;涂层的摩擦学性能随偏压的增大而先增强后降低,当负偏压为40 V时,涂层磨损率为5.0×10~(-6)mm~3/Nm,当负偏压为50 V时,涂层则降低至5.0×10~(-6)mm~3/Nm,为最低值,随着负偏压增加到80 V时,磨损率较高,约9.0×10~(-6)mm~3/Nm。     

车用316L不锈钢表面脉冲磁控溅射CrAlN涂层组织和摩擦性能分析

采用高功率脉冲与脉冲直流磁控溅射相结合的方法,在车用316L不锈钢表面制备得到CrAlN涂层,分析了各基体偏压状态下CrAlN涂层的化学成分及其组织和性能的变化。结果表明:当基体偏压提高后,涂层的(111)晶面衍射峰发生了小角度偏移的变化。随着偏压由0V逐渐增大至-25V时,得到的CrAlN涂层硬度和弹性模量分别升到最大值23.2GPa和228GPa。当基体偏压上升后,涂层厚度发生了先增大再降低的变化现象,最小涂层厚度约1.41μm。并且当偏压增大后CrAlN涂层也达到了更大的内应力,最大值出现于-100V,等于2.52GPa。当基体偏压提高后,得到的CrAlN涂层摩擦系数不断降低,从0.49减小为0.31,在0V下达到了最大的磨损率。可以发现,当基体偏压升高后,涂层的磨损作用降低,并且磨痕宽度也变小。     

PCrNi3Mo钢表面磁控溅射CrN涂层工艺优化及性能

采用磁控溅射技术在PCrNi3Mo钢表面沉积了CrN涂层。利用激光共聚焦显微镜、扫描电镜(SEM)、纳米压痕仪、X射线衍射仪(XRD)对涂层的形貌、硬度与弹性模量和相结构进行了表征,研究了基体负偏压、溅射电流和N2/Ar流量比对溅射涂层结构和力学性能的影响。结果表明:在基体负偏压为100 V、溅射电流为0.2 A、N2/Ar流量比为1时溅射的CrN涂层质量最佳,其硬度和弹性模量分别为21.38 GPa和272.71 GPa,较PCrNi3Mo钢基体的硬度(5.57 GPa)与弹性模量(258 GPa)明显提高。     

梯度基体负偏压真空多弧离子镀沉积TiN涂层及其力学性能

目的通过梯度基体负偏压沉积工艺,获得综合性能优良的Ti N涂层。方法采用多弧离子镀工艺,在0~-180 V连续变化的梯度基体负偏压参数下沉积梯度Ti N涂层。通过X射线衍射仪和扫描电子显微镜对涂层的物相结构和形貌进行分析,通过纳米压痕和纳米划痕对涂层的力学性能进行系统研究。结果与无梯度沉积的涂层相比,梯度基体负偏压沉积Ti N涂层的(111)晶面衍射峰减小,厚度增加,表明涂层的沉积速率增大。经测试,梯度涂层的断裂临界载荷L_(c2)=215.21 m N,硬度值H=31.2GPa,弹性模量E=498 GPa,塑性变形临界载荷L_y=81.65 m N;无梯度沉积涂层的L_(c2)=248.63 m N,H=29.6 GPa,E=452 GPa,L_y=23.39 m N。二者相比之下,梯度涂层虽然断裂临界载荷有所减小,但硬度值和弹性模量均有所增大,并且塑性增大,塑性变形临界载荷大幅增加,综合力学性能提高。结论梯度基体负偏压沉积工艺改变了常规的单一参数设置,在沉积过程中,基体负偏压对涂层生长的影响不断改变,获得的涂层具有结构上的梯度变化,从而力学性能得到了改善。     

基体偏压对TiAlN涂层性能的影响

基体偏压是多弧离子镀沉积TiAlN涂层工艺中的一个重要参数,它对涂层的结构以及涂层生长速度有重要影响.通过改变沉积过程中的基体偏压,发现TiAlN涂层表面熔滴的密度和直径随基体负偏压的增加而减小,涂层的显微硬度随着基体负偏压的增加而增加,孔隙率随着基体负偏压的升高而降低.     

电热线爆定向喷涂制备stellite/WC复合涂层的特性

利用电热线爆定向喷涂方法在45钢基体上制备了stellite/WC复合涂层,运用扫描电镜及能谱分析对复合涂层的形貌、微观结构以及涂层的基体结合机理进行了分析,利用纳米硬度计测量了复合涂层的硬度和弹性模量.结果表明:涂层致密,无层状结构出现;喷涂过程中涂层颗粒在基体上的快速凝固使得涂层晶粒细小均匀,晶粒为200～500 nm;涂层与基体界面发生了元素扩散现象,为扩散-冶金结合;涂层硬度的最大值为18.6 GPa,模量的最大值为310 GPa,硬度和模量沿横截面都呈现先增加而后减小的变化趋势.     

基体负偏压对四面体非晶碳膜结构和性能的影响

采用自主研制的45°单弯曲磁过滤阴极电弧沉积系统于Si基体表面制备了四面体非晶碳(ta–C)膜,研究了基体负偏压对薄膜沉积速率、成分、力学性能及摩擦学性能的影响规律。结果表明,随基体负偏压升高,ta–C膜sp3键含量呈先增后减的变化趋势,在-50 V时达到最大值（约64%）;其硬度和弹性模量呈相似的变化规律,在-50 V偏压下获得最大值(48.22 GPa和388.52 GPa)。ta–C薄膜的摩擦学性能与其sp3碳杂化键的含量密切相关,在-50 V偏压下制备的薄膜具有最小平均摩擦系数值（0.10）。可见,采用单弯曲磁过滤阴极弧电弧制备ta–C薄膜的力学和摩擦学特性主要受薄膜中sp3键含量的制约。     

真空退火对多弧离子镀Ti-Al-N涂层的影响

采用多弧离子镀技术和后续的真空退火工艺在06Cr19Ni10不锈钢基体上制备了Ti2AlN涂层;研究了多弧离子镀工艺及退火处理对涂层的成分、相组成以及摩擦系数等性能的影响。结果表明,沉积时氮气通量以及退火温度的选择是Ti2AlN相形成的关键因素,在氮气通量40 nm3/h、负偏压400 V、靶电流75 A、占空比90%的条件下镀制的涂层经700℃真空退火获得了纯度较高的Ti2AlN涂层,其硬度为7.2 GPa,摩擦系数仅为0.18。     

脉冲磁控溅射MoS2涂层的组织结构及摩擦学性能

采用单极性脉冲磁控溅射技术在A286基体表面制备MoS₂低摩擦系数涂层(LFC)。利用XRD、SEM等手段表征涂层的成分与微观组织;采用原位纳米力学测试系统、球-盘式摩擦磨损试验机分析涂层的力学和摩擦学性能,并探讨了脉冲偏压对涂层结构、力学和摩擦学性能的影响。结果表明,脉冲偏压由300V增加到600V,MoS₂涂层择优取向发生了(002)向(100)转变,当脉冲偏压增至800V时又恢复(002)择优取向,;随着脉冲偏压的增加,涂层的硬度及弹性模量出现先减少后增大趋势,摩擦系数在0.065~0.076范围内波动,呈现出先增加后减小趋势;偏压为800V的涂层摩擦学性能最佳,其磨损率仅为基体的13.5%。     

Mechanical and tribological properties of multi-element (AlCrTaTiZr)N coatings

Multi-element (AlCrTaTiZr)N coatings are deposited onto Si and cemented carbide substrates by reactive RF magnetron sputtering in an Ar + N₂ mixture. The influence of substrate bias voltage, ranging from 0 to − 200 V, on the microstructural, mechanical and tribological properties of these nitride coatings is studied. A reduction in concentration of N and Al is observed with increasing substrate biases. The (AlCrTaTiZr)N coatings show the face-centered-cubic crystal structure (B1-NaCl type). The use of substrate bias changes the microstructure of the (AlCrTaTiZr)N coating from the columns with microvoids in boundaries to the dense and less identified columns. The compressive macrostress increases from − 0.9 GPa to − 3.6 GPa with an increase of substrate bias. The hardness and adhesion increase to peak values of 36.9 GPa and 60.7 N at the bias voltage of − 150 V, respectively. The tribological properties of the (AlCrTaTiZr)N coatings against 100Cr6 steel balls are evaluated by a ball-on-disc tribometer with a 10 N applied load. With an increase of substrate bias, the wear rate reduces while the friction coefficient almost keeps constant at 0.75. The lowest wear rate of 3.65 × 10^− 6 mm³/Nm is obtained for the (AlCrTaTiZr)N coating deposited at the bias voltage of − 150 V.     

Structure and properties of selected (Cr–Al–N,TiC–C,Cr–B–N) nanostructured tribological coatings

The paper will present the state-of-art in the process, structure and properties of nanostructured multifunctional tribological coatings used in different industrial applications that require high hardness, toughness, wear resistance and thermal stability. The optimization of these coating systems by means of tailoring the structure (graded, superlattice and nanocomposite systems), composition optimization, and energetic ion bombardment from substrate bias voltage control to provide improved mechanical and tribological properties will be assessed for a range of coating systems, including nanocrystalline graded Cr_1−xAl_xN coatings, superlattice CrN/AlN coatings and nanocomposite Cr–B–N and TiC/a-C coatings. The results showed that the superlattice CrN/AlN coating exhibited a super hardness of 45 GPa when the bilayer period Λ was about 3.0 nm. Improved toughness and wear resistance have been achieved in the CrN/AlN multilayer and graded CrAlN coatings as compared to the homogeneous CrAlN coating. For the TiC/a-C coatings, increasing the substrate bias increased the hardness of TiC/a-C coatings up to 34 GPa (at −150 V) but also led to a decrease in the coating toughness and wear resistance. The TiC/a-C coating deposited at a −50 V bias voltage exhibited an optimized high hardness of 28 GPa, a low coefficient of friction of 0.19 and a wear rate of 2.37 × 10⁻⁷ mm³ N⁻¹ m⁻¹. The Cr–B–N coating system consists of nanocrystalline CrB₂ embedded in an amorphous BN phase when the N content is low. With an increase in the N content, a decrease in the CrB₂ phase and an increase in the amorphous BN phase were identified. The resulting structure changes led to both decreases in the hardness and wear resistance of Cr–B–N coatings.     

偏压对MPP制备AlTiSiN纳米复合涂层结构及性能的影响

目的实现对AlTiSiN纳米复合涂层微观组织结构的调控及力学性能优化。方法利用可调控脉冲磁控溅射技术,通过调控基体偏压(-50～-250 V)制备了不同偏压条件下的AlTiSiN纳米复合涂层。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、能量色散谱仪(EDS)、原子力显微镜(AFM)、薄膜综合性能测试仪及球盘摩擦试验仪,测试了涂层的微观组织结构、组成成分、表面形貌、力学性能及摩擦学性能。结果偏压对涂层元素组成影响不大。微观组织结构方面,不同偏压条件下制备AlTiSiN纳米复合涂层的晶面衍射峰宽化现象明显,呈现纳米晶组织结构。-200V条件下制备的涂层的晶面衍射峰呈"馒头峰"形态,表明涂层结晶性能出现明显下降,呈类非晶组织结构;偏压升至-250V时,高能离子对涂层生长表面的持续轰击作用,使得涂层生长表面升温明显,导致结晶性能出现明显改善。涂层表面光滑致密,表面粗糙度最低可达1.753nm。力学性能方面,随基体偏压的升高,涂层硬度在取得最大值后逐渐下降,最高硬度可达25.9 GPa,H/E*系数可达0.13。摩擦学性能方面,偏压为-200 V时,涂层磨损率取得最小值4.7×10~(-15) m~3/(N×m)。结论改变基体偏压,成功实现了涂层微观组织结构的调控生长,进而达到了优化涂层组织结构、力学性能及摩擦学性能的目的。     

不同气氛下电火花沉积钛合金涂层的组织性能

分别在氮气、氩气和空气3种气氛下,在45钢上电火花沉积制备TC4钛合金涂层。利用OM、SEM、EDS、XRD、XPS等对钛合金沉积层的微观形貌、组织结构进行分析;利用纳米力学探针仪测试对比沉积层的力学性能;采用CETR摩擦磨损仪测试涂层的耐磨性。结果表明:氮气下电火花沉积生成含TiN及少量TiO和TiO2的陶瓷增强层。氮气中制取的涂层微裂纹较明显,但几无坑蚀和微孔,表面形貌优于氩气和空气下的沉积层。纳米硬度高达15.18GPa,无需增加沉积层厚度,即可获得较高硬度和抗变形能力。其摩擦因数为0.41,磨损量为2.2mg,均远低于45钢,也低于空气和氩气下制备的普通的钛合金涂层,并且改善了钛合金涂层的粘着磨损。     

温度对WC-WB-CoCr涂层高温摩擦磨损性能的影响

采用超音速火焰喷涂(HVOF)制备了WC-WB-CoCr涂层,研究了温度对WC-WB-CoCr涂层高温摩擦磨损性能的影响。通过SEM、XRD和显微硬度仪对涂层的微观组织、相结构和力学性能进行表征。通过摩擦磨损试验机和拉曼光谱仪研究了WC-WB-CoCr涂层的高温摩擦学性能和氧化产物,采用台阶仪扫描磨痕形貌并计算WC-WB-CoCr涂层的磨损率。结果表明：WC-WB-Co-Cr涂层主要由WC和CoW₂B₂组成,涂层结构致密,与基体结合紧密;随着磨损试验温度升高,涂层的摩擦系数从0.66降低到0.57,涂层的磨损率随着温度的升高而升高,但是其磨损率增长程度随着温度的升高而降低。在高温磨损过程中,磨痕表面的氧化膜主要由WO₃和CoWO₄组成,且CoWO₄比WO₃表现出更好的耐高温磨损性能。涂层的主要磨损机制为氧化磨损、疲劳磨损和粘着磨损。     

CrN/CrAlSiN涂层海水环境下的摩擦学性能

为提高海洋装备摩擦零部件的摩擦学性能,采用多弧离子镀技术在316L不锈钢上制备了CrN/CrAlSiN涂层。通过XRD、XPS表征涂层的物相及成分,SEM和TEM表征涂层的形貌和微观结构,并用纳米压痕仪测试其硬度,采用摩擦磨损试验机对涂层在大气和海水环境中的摩擦磨损性能进行测试。结果表明:CrN/CrAlSiN涂层的微观结构主要有CrN相、AlN相以及非晶态Si_3N_4包裹CrN、AlN相,(111)择优取向最为明显;基于微观结构与CrN过渡层的设计,CrAlSiN涂层硬度高达35.5 GPa;较之于316L基底,涂层致密的结构使其在海水环境下表现出更好的耐腐蚀性能;在大气和海水环境下,CrN/CrAlSiN涂层的摩擦因数及磨损率均明显降低,在海水环境下达到最优。     

添加氧化镧的纳米Al2O3-13%TiO2等离子喷涂涂层高速摩擦磨损性能

以添加了少量氧化镧的团聚纳米Al2O3-13%TiO2粉末为原料,利用等离子喷涂技术制备了纳米陶瓷涂层。在MMS-1G型高速摩擦磨损试验机进行了摩擦磨损试验,利用扫描电镜和能谱仪对磨损表面进行了表征。结果表明:涂层组织呈现出典型的层状结构特征,界面结合良好。在高速摩擦磨损试验中,随着载荷的增加,涂层摩擦因数下降,而涂层微裂纹扩展引起涂层剥落,导致磨损率升高。     

Sliding wear characteristics of solid lubricant coating on titanium alloy surface modified by laser texturing and ternary hard coatings

Titanium alloys are poor in wear resistance and it is not suitable under sliding conditions even with lubrication because of its severe adhesive wear tendency. The surface modifications through texturing and surface coating were used to enhance the surface properties of the titanium alloy substrate. Hard and wear resistant coatings such as TiAlN and AlCrN were applied over textured titanium alloy surfaces with chromium as interlayer. To improve the friction and wear resisting performance of hard coatings further, solid lubricant, molybdenum disulphide (MoS2), was deposited on dimples made over hard coatings. Unidirectional sliding wear tests were performed with pin on disc contact geometry, to evaluate the tribological performance of coated substrates. The tests were performed under three different normal loads for a period of 40 min at sliding velocity of 2 m/s. The tribological behaviours of multi-layer coatings such as coating structure, friction coefficient and specific wear rate were investigated and analyzed. The lower friction coefficient of approximately 0.1 was found at the early sliding stage, which reduces the material transfer and increases the wear life. Although, the friction coefficient increased to high values after MoS₂ coating was partially removed, substrate was still protected against wear by underlying hard composite layer.     

脉冲能量对电火花沉积Mo_2FeB_2基金属陶瓷涂层组织与性能的影响

为研究脉冲能量对电火花沉积制备Mo2Fe B2基金属陶瓷涂层组织及性能的影响,在3种脉冲能量(1.35,6.41和17.81 J)下分别制备了沉积涂层。采用扫描电镜(SEM)、X射线衍射仪(XRD)、电子探针(EPMA)、显微硬度计及摩擦磨损实验机对涂层的组织与性能进行研究和表征。结果表明:3种脉冲能量所制备的涂层物相组成均由非晶相、马氏体和Fe3B相组成,脉冲能量17.81 J时涂层的非晶相含量最低;单个沉积点的溅射范围和涂层表面裂纹数随着脉冲能量的增大而增大,涂层厚度随脉冲能量增加到一定厚度后变化不显著;涂层与基体间形成良好的冶金结合。脉冲能量6.41 J时,涂层截面具有最高的峰值显微硬度1 349 HV0.05;同时,该涂层稳定阶段的摩擦因数(0.313)和1 h磨损量(0.7 mg)均为3种涂层中最低,耐磨性最佳。