HiPIMS复合热处理制备高纯Ti2AlC MAX相涂层

Ti₂AlC MAX 相涂层是一类兼具金属和陶瓷特性的具有密排六方结构的高性能陶瓷涂层,在电接触、高温防护、宽温域摩擦等领域具有广阔的应用前景。然而 MAX 相涂层的成相成分窗口窄,性能受杂质相影响大,实现高纯、致密 Ti₂AlC MAX 相涂层的制备目前仍存在挑战。考虑沉积气压与溅射等离子体能量密切相关,采用高功率脉冲复合直流磁控溅射技术在钛合金基体上制备了 TiAl / Ti-Al-C 涂层,经后续热处理退火得到高纯 Ti₂AlC MAX 相涂层,重点研究不同沉积气压对涂层退火前后的成分、微观结构以及力学性能的影响和作用机制。结果表明,随着气压不断增大,沉积态涂层厚度先增加后减少。其中低沉积气压下沉积态涂层退火后,结构中除了 Ti₂AlC MAX 相外,还含有一定量杂质相;而在高气压下沉积态涂层退火后几乎全部转变为 Ti₂AlC MAX 相,呈现高纯、表面光滑致密的 MAX 相涂层特征。相较于沉积态涂层,退火后的涂层硬度变化不大,但由于生成了 Ti₂AlC MAX 相,涂层弹性模量有所提高。     

占空比对脉冲电弧离子镀AlCrSiN涂层热稳定性和抗氧化性的影响

采用脉冲和直流电弧离子镀技术制备AlCrSiN涂层,研究占空比对涂层结构和性能的影响。采用扫描电镜观测涂层的生长形貌和化学成分,利用XRD分析涂层的相组成,结合光电子能谱技术分析涂层中元素化学键价,并通过纳米压痕法检测涂层的硬度和弹性模量。此外,对涂层进行真空退火和氧化处理,以评价涂层的高温结构和力学稳定性以及抗氧化性。结果表明：AlCrSiN涂层均为非晶Si₃N₄包裹纳米晶（Al, Cr）N的纳米复合结构;脉冲电弧沉积可以改善涂层的表面质量、提高组织致密性和硬度。占空比为1%时,AlCrSiN涂层具有最小的表面粗糙度（47 nm）和最高的硬度（31.5 GPa）。AlCrSiN涂层具有良好的热稳定性,950℃退火后其硬度仍高于30 GPa。AlCrSiN涂层的抗氧化温度超过1000℃;占空比的增加涂层的抗氧化性略有提升。     

Ti3AlC2掺杂SPS法制备Ti2AlC/TiAl复合材料的研究

通过2TiC-Ti-1.2Al体系的原位热压反应制备了Ti₃AlC₂陶瓷,然后以59.2Ti-30.8Al-10Ti₃AlC₂(wt%)为反应体系,采用放电等离子烧结技术制备出Ti₂AlC/TiAl基复合材料。借助XRD、SEM分析了产物的相组成和微观结构,并测量了其室温力学性能。结果表明：原位热压烧结产物由Ti₃AlC₂和TiC相组成,Ti₃AlC₂呈典型的层状结构,TiC颗粒分布在其间。SPS法制备的Ti₂AlC/TiAl基复合材料主要由TiAl、Ti₃Al和Ti₂AlC相组成,Ti₂AlC增强相主要分布于基体晶界处,表现为晶界/晶内强化作用。力学性能测试表明：Ti₂AlC/TiAl基复合材料的密度、维氏硬度、断裂韧性和抗弯强度分别为3.85 g/cm₃、5.37 GPa、7.17 MPa?m_1/2和494.85 MPa。     

不同双层结构AlCrN/AlCrVN多层涂层的力学和磨损性能

采用电弧离子镀的方法制备了不同数目（1、2、4、6）双层结构的AlCrN/AlCrVN多层涂层,并研究了多层结构对涂层微观结构、力学、摩擦学和切削性能的影响。结果显示,沉积态AlCrN/AlCrVN多层涂层主要由固溶(Al,Cr)N组成,优先生长方向为[111]晶向。与其他多层涂层相比,具有6层双层结构的AlCrN/AlCrVN涂层在高温下表现出较低的摩擦系数（约0.46）和磨损率（0.15×10^-11 m³/N·m）,以及较高的硬度（HK_0.05=38 000 MPa）和膜-基结合强度（L_C2=53±1 N）。多层涂层相邻层之间形成了较多的界面,有助于提高多层涂层的硬度和耐磨性。切削试验结果显示,当切削磨损标准VB=0.2时,AlCrN/AlCrVN-6涂层具有较高的硬度和耐磨性,最长的切削长度为7.4 m。     

氩弧熔敷原位合成TiC-TiB2/Ti基复合涂层组织及性能分析

利用氩弧熔敷技术,在TC4合金表面原位合成了TiC-TiB₂增强镍基复合材料涂层,利用SEM和XRD等方法分析了涂层的显微组织并测试了涂层的显微硬度.结果表明,熔敷组织主要由TiC,TiB₂和Ti(Ni,Cr)组成,TiB₂主要以棒状形式存在;在所形成的TiC-TiB₂/Ti复合材料层中,TiC和TiB₂颗粒分布均匀且尺寸细小;熔敷涂层由表及里组织不同;熔敷层与基体呈冶金结合,无气孔、裂纹等缺陷;涂层的显微硬度达到13.8 GPa,较基体提高了4.5倍.     

O2/Ar流量比及退火对氧化锆薄膜结构及摩擦学性能的影响

采用多弧离子镀(MAIP)方法在 Inconel 718 高温合金基体上沉积了氧化锆(ZrO_x )薄膜,并对该薄膜进行了 800 ℃退火处理;研究了 O₂ / Ar 两种气体流量比 R_{O2/ Ar}(0. 25、0. 43、0. 67、1. 00、1. 50)及退火处理对沉积态薄膜的微观结构、力学性能及摩擦学性能的影响。 结果表明:随着 R_{O2/ Ar} 从 0. 25 升高到 1. 50,沉积态薄膜的主要物相组成由不稳定的锆的氧化物(h-ZrO_{0. 35} 、h-ZrO₂ 、h-Zr₃O)逐渐转变为稳定的 m-ZrO₂ ,薄膜截面结构由起初疏松的柱状晶逐渐转变为排列致密的柱状晶,薄膜硬度逐渐升高,O₂ / Ar 比为 1. 50 时最大为 16. 7 GPa。 低 R_{O2/ Ar} 下沉积的薄膜摩擦学性能很差,很快磨穿失效。 当 R_{O2/ Ar} 超过 0. 67 时,薄膜的摩擦寿命显著提高,R_{O2/ Ar} 为 1. 50 时薄膜磨损率最低为 1. 45×10^-6 mm³ / (N·m)。 沉积态薄膜经过退火处理后主要物相转变为 m-ZrO₂ ,薄膜表面变得更加光滑致密,薄膜硬度、弹性模量以及摩擦学性能均较退火前明显改善。     

激光重熔Al2O3-TiO2涂层的强韧性能

采用等离子喷涂和激光重熔复合工艺在Ti-6Al-4V基体上制备了Al₂O₃-TiO₂涂层,通过X射线衍射(XRD)、扫描电镜(SEM)、显微硬度试验和压痕试验等方法研究了激光重熔对涂层的组织及强韧性能的影响.结果表明,等离子喷涂Al₂O₃-TiO₂涂层中的主相为γ-Al₂O₃,而相应重熔涂层中的主相为α-Al₂O₃.激光重熔可消除喷涂态涂层内部的孔隙、微裂纹和层状堆垛等微观缺陷,获得致密化的组织,并使涂层与基体形成良好冶金结合.重熔涂层的硬度比相应喷涂态涂层约提高了50%,裂纹扩展抗力相比喷涂态涂层提高了近两倍.激光重熔纳米涂层中的未熔增强颗粒和纳米结构特性等对涂层起到了协同强化和韧化作用.     

多弧离子镀制备Cr/CrN多层厚膜的微观结构和力学性能

通过多弧离子镀（MAIP）在室温下将具有不同调制比（1:2、1:3、1:5）的多层Cr/CrN厚涂层沉积在A100钢基底上。腔室温度在沉积过程中由室温逐渐升高到160~170 ℃。设计调制结构是为了使膜/基结合强度和机械性能最大化。调制比为1:2的Cr/CrN多层涂层表现出最高的膜/基结合强度（L_c=63.8 N）,这可能归因于最高的材料硬度(H)/弹性模量(E)和H³/E²数值比（分别为0.083和0.138）。Cr层越厚,多层Cr/CrN厚涂层的塑性和摩擦学性能越好。干摩擦试验表明,与单层CrN相比,Cr/CrN多层涂层的平均摩擦系数和比磨损率分别最高降低了24%和94%。随着Cr层变厚,磨损机理从表面疲劳磨损转变为磨料磨损,这种现象可归因于硬度和塑性的协调变化。     

激光辅助热喷涂NiCoCrAlYTa/ZrO2/BaF2·CaF2涂层的组织及性能∗

高温耐磨涂层是航空发动机关键摩擦副可靠使用的重要保障,鉴于其服役环境日益严苛复杂,进一步提高涂层的高温耐磨性能是十分必要的。利用激光辅助热喷涂技术制备 NiCoCrAlYTa / ZrO₂ / BaF₂·CaF₂ 高温耐磨涂层,利用 SEM、EDS 分析高温耐磨涂层的横截面微观组织及化学成分,研究 ZrO₂ / BaF₂·CaF₂质量分数、激光功率及扫描速度对耐磨涂层微观组织、力学性能及高温耐磨性能的影响。结果表明：激光辅助处理可以诱导耐磨涂层表面形成具有树枝状结构的 ZrO₂陶瓷层; 当激光功率为 80 W,扫描速度为 8 mm / s,喷涂粉末为 75 wt.% NiCoCrAlYTa+25 wt.% ZrO₂ / BaF₂·CaF₂时,制备涂层的微观组织、综合力学性能及高温耐磨性能达到最好;在此工艺参数下,涂层顶部的 ZrO₂ 陶瓷层最为致密均匀,其平均纳米硬度为 13.6 GPa,平均弹性模量为 182.5 GPa,800 ℃时的磨损率为 2.7×10^?5 mm³ ·N^?1 ·m^?1 。将高温耐磨涂层的组分设计与激光辅助热喷涂工艺相结合,可为提高涂层综合性能的提供解决途径。     

部分MAX相在NaOH、H2SO4和HCl中的电化学性质

用热压的方法合成了若干MAX相化合物,包括相（Ti₂AlC和Ti₂AlN）和312相（Ti₃SiC₂和Ti3AlC2）;研究了它们在1 mol/L HCl、1 mol/L NaOH和1 mol/L H₂SO₄中的电化学性质及其结构与其稳定性的关系.结果表明:在所有溶液中,312型MAX相比211相更稳定;Ti₃SiC₂ 和Ti₃AlC₂几乎在所有溶液里都发生钝化,而Ti₂AlC和Ti₂AlN在1 mol/L HCl中活跃地溶解,还伴有大量气泡产生;Ti₃SiC₂比Ti₂AlC、Ti₂AlN 和Ti₃AlC₂更稳定.     

等离子体增强磁控溅射CrSiN涂层摩擦磨损行为

目的基于细晶强化理论,借助新型涂层制备技术获得综合性能优良的CrSiN涂层,研究Si含量对涂层微观结构、力学性能及耐磨性能的影响规律。方法采用等离子体增强磁控溅射技术,制备四种含有不同Si含量的Cr Si N涂层。使用X射线能谱仪(EDS)、X射线衍射仪(XRD)、场发射扫描电子显微镜(FE-SEM)和原子力显微镜(AFM),分析涂层的化学成分、晶体结构、微观形貌和表面粗糙度。使用纳米压痕/划痕仪测试涂层的显微硬度、杨氏模量和结合力。使用摩擦磨损试验仪考察涂层的摩擦磨损行为。结果 Cr Si N涂层中Si含量随着Si靶功率的增加而增加。所有涂层中均未检测到含Si物相,主要由Cr N相组成。随着Si含量的增加,CrN(111)衍射峰逐渐减弱直至消失,涂层由疏松的三角锥结构逐渐变为致密平整的CrN纳米晶和Si3N4非晶共存的复合结构,涂层表面粗糙度显著降低,涂层的显微硬度、杨氏模量、结合力及耐磨性能均呈现先增后降的趋势。结论 Si含量为18.5%的Cr Si N涂层具有最佳的耐磨性能,此时涂层的硬度、杨氏模量、结合力和平均摩擦系数分别约为27 GPa、327 GPa、30 N和0.289。     

直流基体偏压对Al-Cr-Si-N涂层结构和力学性能的影响

采用电弧离子镀技术在不同直流偏压下沉积Al-Cr-Si-N涂层,研究基体偏压对涂层成分、微观结构和性能的影响。结果表明:Al-Cr-Si-N涂层以密排六方结构和面心立方结构的AlN相为主,随着基体负偏压增加,涂层的衍射峰整体向小角度方向偏移:涂层内残余压应力逐渐增加,最大值为-0.77 GPa;涂层硬度和摩擦系数变化不明显。当基体负偏压为-40V时,Al-Cr-Si-N涂层的特征参数H/E和H~3/E~(*2)均达最大值,分别为0.15和0.37GPa,此时涂层具有最佳的耐磨性能,摩擦系数亦最低。     

Depth profile analyses of nc-TiC/a-C:H coating prepared by balanced magnetron sputtering

Nanocrystalline titanium carbide embedded in an hydrogenated amorphous carbon matrix (nc-TiC/a-C:H) shows high hardness and Young's modulus together with low wear and low friction coefficient. In this paper, we report on the preparation of well adherent nc-TiC/a-C:H coatings ~ 5 μm thick on stainless steel substrates using a well balanced magnetic field configuration and only very low power RF bias on the substrate. Hardness and Young's modulus of these coatings are 43 GPa and 380 GPa, respectively. The mechanical properties – hardness and Young's modulus – measured from the coating's top reach the values obtained at optimized experiments where the unbalanced magnetic field configuration was used. A simple method of depth profiling suitable for evaluation of mechanical properties of several micrometers thick coatings is developed and employed. The paper reports on the depth profile analyses of the coating hardness, Young's modulus, composition and morphology.     

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.     

MAX/金属基自润滑复合涂层研究现状与展望*

MAX / 金属基自润滑复合涂层具有优异的力学性能和摩擦学性能,MAX 相的加入拓宽了金属基复合涂层的研究和应用范围。首先分析 MAX / 金属基复合涂层在摩擦磨损过程中自润滑特性是如何起作用的,分别从 MAX 相的本质结构说明自润滑性能的存在,摩擦过程中润滑膜的生成说明提高减摩润滑性能的原因。随后阐述近年常见几种 MAX 相涂层以及 MAX / 金属基复合涂层的制备和特性,包括 Ti₂AlC、Cr₂AlC 涂层、高低温金属基体下的 MAX 复合涂层。最后归纳总结 MAX / 金属基复合涂层常见应用领域和表面防护效果,并对 MAX / 金属基复合涂层目前存在的问题和涂层质量的提升进行展望,为 MAX / 金属基自润滑复合涂层的推广应用提供参考。     

同步脉冲偏压对HiPIMS技术低温沉积CrN涂层结构及性能影响*

针对高性能 CrN 涂层无法实现低温可控制备的技术瓶颈,利用具备高溅射材料离化率的高功率脉冲磁控溅射技术,调控同步脉冲偏压,改善涂层生长动力学条件,实现 CrN 涂层的低温可控沉积。开展同步脉冲偏压与涂层化学组成、组织结构、 力学、摩擦学及耐腐蚀性能间关联关系研究。同步脉冲偏压在提升沉积离子束流迁移能的同时可显著降低荷能 Ar⁺ 对成膜表面的持续轰击作用,达到改善涂层致密性及膜基结合力的目的。此外,沉积 CrN 涂层晶粒细化显著,硬度及弹性模量明显升高,最高可达 13.8 GPa、236.7 GPa。涂层力学性能优化及致密性提升显著改善了摩擦学与耐腐蚀性能,涂层磨损率最低可达 2.49×10^?15 m³ / (N·m),同时涂层可耐受 120 h 中性盐雾腐蚀环境考核。为实现高性能 CrN 涂层的低温可控制备,扩展其在温度敏感基体领域的适用范围提供了新的设计思路与技术支撑。     

Syntheses and mechanical properties of Cr-Mo-N coatings by a hybrid coating system

Effects of Mo content up to 30.4 at.% on the microstructure and mechanical properties of CrN coatings are reported in this study. Ternary Cr-Mo-N coatings were deposited onto steel substrates (AISI D2) using a hybrid coating method of arc ion plating (AIP) using Cr target and DC magnetron sputtering technique using Mo target in N₂/Ar gaseous mixture. The synthesized Cr-Mo-N coatings formed a substitutional solid solution of (Cr,Mo)N where larger Mo atoms replaced Cr in CrN crystal. The Cr-Mo-N coatings showed increased hardness value of approximately 34 GPa at 21 at.% Mo, compared with 18 GPa for pure CrN. The friction coefficient decreased from 0.49 for pure CrN coating to 0.37 for Cr-Mo-N with 30.4 at.% Mo. This result is believed to be due to tribo-layer formation of MoO₃ which is known to function as a solid lubricant.     

Ti2AlC coatings deposited by High Velocity Oxy-Fuel spraying

High Velocity Oxy-Fuel has been utilized to spray coatings from Ti₂AlC (MAXTHAL 211^®) powders. X-ray diffraction showed that the coatings consist predominantly of Ti₂AlC with inclusions of the phases Ti₃AlC₂, TiC, and Al-Ti alloys. The fraction of Ti₂AlC in coatings sprayed with a powder size of 38 μm was found to increase with decreasing power of the spraying flame as controlled by the total gas flow of H₂ and O₂. A more coarse powder (56 μm) is less sensitive to the total gas flow and retains higher volume fraction of MAX-phase in the coatings, however, at the expense of increasing porosity. X-ray pole figure measurements showed a preferred crystal orientation in the coatings with the Ti₂AlC (000l) planes aligned to the substrate surface. Bending tests show a good adhesion to stainless steel substrates and indentation yields a hardness of 3-5 GPa for the coatings sprayed with a powder size of 38 μm.     

Variation of microstructure and composition of the Cr2AlC coating prepared by sputtering at 370 and 500 °C

Cr₂AlC coating was deposited at 370 and 500 °C by D.C. magnetron sputtering from an as-synthesized bulk Cr₂AlC target. The phase composition and preferential orientation of the coating were investigated using XRD, and the microstructure of the coating was characterized by TEM. Results indicated that Cr₂AlC coating with a strong (110) preferential orientation could be obtained. The coating microstructure was clearly affected by the deposition temperature. At 370 °C, the deposited coating possessed a triple-layered structure with an α-(Cr, Al)₂O₃ inner layer, an amorphous intermediate layer and a crystalline Cr₂AlC outer layer. However, the coating deposited at 500 °C had a single-layered structure consisting of crystalline Cr₂AlC layer. The growth mechanism of the Cr₂AlC coating at different deposition temperatures is discussed.