TiB_2陶瓷粉末纳米化改性及其增强环氧复合涂层的制备与表征（英文）

低温条件下,以钛酸丁酯为原料,采用胶溶-回流方法在Ti B_2粉体表面包覆纳米Ti O_2颗粒。通过SEM、XRD、BET等分析检测方法对复合颗粒的表观形貌、包覆层相成分、比表面积等进行表征。结果显示,纳米Ti O_2颗粒均匀离散地包覆在Ti B_2粉体表面,包覆层主要为锐钛矿型相,Ti B_2粉体纳米化改性后复合颗粒的表面粗糙度显著增加,比表面积较包覆前提高35倍以上。将包覆后的Ti B_2粉体引入环氧树脂制备耐磨复合涂层,测得其磨损失重仅为包覆前复合耐磨涂层的50%,其耐磨性显著提高,并初步分析了复合耐磨涂层的摩擦磨损性能、磨损形貌及耐磨机理。     

TiO2/膨润土复合光催化材料的常温制备及性能研究

采用改进的溶胶-凝胶法,在以水为主要溶剂的反应体系中,控制钛酸四丁酯充分水解、缓慢聚合,在 常压、低温(70℃)的温和条件下制备出稳定的TiO₂纳米晶溶胶,并利用TiO₂纳米晶溶胶在膨润土表面负载,获得TiO₂/膨润土复合光催化材料。采用 X 射线衍射、扫描电镜、比表面积测定等研究手段对样品的结构形貌进行了表征,并考察了其光催化活性。结果表明：较高的水用量有利于TiO₂晶体形成,当去离子水:钛酸四丁酯摩尔比大于167:1时,在溶胶体系中出现了锐钛矿型TiO₂纳米晶体;TiO₂纳米晶主要负载于膨润土表面,并未嵌入到膨润土层间结构,但相对于单一膨润土,TiO₂负载显著提高了材料比表面积;当去离子水:钛酸四丁酯摩尔比=192:1时,在紫外光照射下,复合光催化材料表现出最高的光催化活性,对亚甲基蓝的降解率达到93.8%。     

压力烧结制备二氧化钛包覆的石墨烯增强铝基复合材料

使用压力烧结方法制备了石墨烯纳米片（GNP）增强的7075铝基纳米复合材料,提出了一种通过在GNP的表面涂覆二氧化钛（TiO₂）来优化界面结合的新工艺,并比对了原石墨烯及具有包覆层石墨烯对铝基纳米复合材料的力学性能和微观结构的影响。结果表明,与添加纯GNP相比,添加具有TiO₂涂层的GNP的纳米复合材料的力学性能提高。相比于基体,TiO₂包覆GNP增强的纳米复合材料的屈服强度、抗拉强度和显微硬度分别增加了38.9%、34.4%和20.1%。性能的进一步改善是由于TiO₂涂层优化了增强相与基体之间的界面结合,从而提高了载荷传递的有效性。     

等离子喷涂 NiCoCrAlY / Al2 O3 涂层的制备及摩擦性能研究

目的制备等离子喷涂NiCoCrAlY/Al2O3高温固体润滑耐磨涂层,并研究该涂层的摩擦性能和磨损机理。方法采用喷雾造粒、化工冶金包覆和固相合金化技术制备NiCoCrAlY/Al2O3复合粉体,用等离子喷涂技术在45#钢表面制备NiCoCrAlY/Al2O3复合涂层。用SEM和XRD等手段分析粉体和涂层的显微结构和物相组成,研究涂层从室温到800℃的摩擦磨损性能,探讨NiCoCrAlY/Al2O3复合涂层在室温和高温下的磨损机理。结果 Al2O3颗粒表面均匀包覆着一层致密的NiCoCrAlY合金,包覆层厚度大约为3~5μm;等离子喷涂NiCoCrAlY/Al2O3复合涂层呈典型的层状结构,涂层各层间结合良好,涂层中孔隙率约为2.84%,主晶相为Ni Cr Al合金相和Al2O3相。涂层的摩擦系数随温度的升高逐渐降低,在室温下约为0.64,800℃时在0.4以下。高温下,金属氧化物的形成是摩擦系数降低的主要原因。涂层的磨损率随温度的升高先升高后降低。涂层在低温下为脆性断裂和磨粒磨损,高温下为氧化磨损、磨粒磨损、塑性变形和金属氧化物的转移。结论等离子喷涂NiCoCrAlY/Al2O3复合涂层是一种性能优良的高温固体润滑耐磨涂层。     

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.     

Ti6Al4V合金激光熔覆NiMoSi复合涂层的高温抗氧化性能

为提高Ti6Al4V合金的高温抗氧化性能,以Ni-48%Mo-32%Si混合粉末为原料,采用激光熔覆技术在Ti6Al4V合金表面制备复合涂层,分析涂层物相、组织结构、高温抗氧化性能及抗磨损性能,并讨论相关机理。结果表明：复合涂层中无裂纹,与基体实现了良好的冶金结合;硬质相Ti₅Si₃、MoSi₂和Mo₅Si₃均匀分布于基体α-Ti、NiTi中。经恒温800 ℃氧化100 h后,复合涂层的氧化膜主要由TiO₂、SiO₂和NiO组成,结构连续致密,表现出较好的高温抗氧化性能。而Ti6Al4V合金氧化膜主要为疏松TiO₂,表面氧化严重;氧化后,复合涂层和基体的单位面积增重分别为1.31和23.38 mg/cm²;复合涂层和基体的摩擦因数分为0.44和0.52、磨损率分别为16.2×10^-5和22.6×10^-5mm³/Nm,复合涂层的摩擦学性能亦有明显提高。     

等离子喷涂 NiCoCrAlY / Al2 O3 高温固体润滑耐磨涂层的抗氧化性能研究

目的研究等离子喷涂NiCoCrAlY/Al2O3高温固体润滑耐磨涂层在850℃时的高温抗氧化性能和抗氧化机理。方法采用喷雾造粒、化工冶金包覆技术制备NiCoCrAlY/Al2O3复合粉体,并采用等离子喷涂技术在45#钢表面制备NiCoCrAlY/Al2O3复合涂层。采用SEM和XRD研究粉体和涂层的显微结构和物相组成,并采用马弗炉研究复合涂层在850℃的恒温氧化动力学曲线,通过研究氧化96 h以后涂层表面的组织形貌,探讨NiCoCrAlY/Al2O3复合涂层的抗氧化机理。结果 NiCoCrAlY合金层均匀致密地包覆在Al2O3颗粒的表面,包覆层厚度约为3~5μm。复合粉体的主要组成为Al2O3相和NiCoCrAlY合金相,没有其他杂质相的存在。等离子喷涂NiCoCrAlY/Al2O3复合涂层氧化动力学曲线分为大斜率直线、抛物线和系数几乎为0的抛物线等3个阶段。氧化96 h以后,涂层的氧化质量增量为4.9 mg/cm2左右,表面形成了一层连续的氧化物保护膜,经EDX分析,氧化膜层主要由Al,O,Cr和Ni组成。结论等离子喷涂NiCoCrAlY/Al2O3复合涂层具有良好的高温抗氧化性能,涂层中Ni,Cr,Al的氧化以及硬质相Al2O3的加入是涂层抗氧化的主要原因。     

微波原位制备作为锂离子电池电极材料的石墨烯/TiO2 纳米复合物

通过改造的家用微波炉,实现了原位高效制备石墨烯/TiO₂纳米复合物。结果表明：微波辅助法能够在商用锐钛矿型TiO₂纳米颗粒表面均匀制备石墨烯纳米片,通过SiO₂/Si的剧烈电晕放电,其制备时间仅需数分钟（最短3 min）。石墨烯纳米片的尺寸大约为50 nm且缺陷很少。TiO₂晶体结构仍为锐钛矿型,主要归功于极短的制备周期和较低的反应温度（600~700 ℃）。石墨烯具有优异的电导率,可以提升锂离子扩散速率、提高电子传输速率并降低接触电阻。在1 C（170 mA·g^-1）条件下石墨烯/TiO₂纳米复合物的电池放电比容量提高了2倍。与商业化锐钛矿型TiO₂纳米颗粒相比,在1 C到5 C的不同充放电倍率下,石墨烯/TiO₂纳米复合物的比容量差距显著扩大。     

Ti 元素对B4C/Al复合材料力学性能的改善作用研究

B₄C/Al复合材料是目前最理想的中子吸收材料,广泛用于乏燃料储存。本文利用液态搅拌法制备B₄C/Al复合材料,通过添加Ti元素,探讨了界面反应对材料的界面结构和力学性能的影响。研究发现,Ti元素通过参与界面反应,改变了界面结构,在B₄C颗粒表面形成了紧密结合的纳米TiB₂界面层;Ti的添加消除了界面微裂纹、微孔、分离等缺陷。随着界面反应程度的加强,材料强度提高,尤其反应脱落的纳米TiB₂颗粒作为原位第二强化相进一步增强基体。B₄C/Al复合材料断裂过程表现为韧窝延性断裂;TiB₂界面层增强了B₄C颗粒与基体的结合,断裂行为从B₄C-Al界面脱落转变为B₄C颗粒断裂;但过渡的界面反应会形成微韧窝,引起材料延伸率下降。     

γ-TiAl合金表面Al2O3/Al复合涂层的抗高温熔盐腐蚀性能研究

采用磁控溅射技术于γ-TiAl合金表面制备Al₂O₃/Al复合涂层。在850 °C下、 100 wt.% Na₂SO₄熔盐中观测Al₂O₃/Al复合涂层的高温腐蚀行为。结果表明,Al₂O₃/Al复合涂层具备由Al₂O₃表层、富Al中间层以及互扩散层组成的梯度结构,因而有效地提高了基体γ-TiAl合金的抗高温腐蚀性能。在腐蚀实验后,涂层试样表面相结构为Al₂O₃,TiO₂和TiAl₃。致密的Al₂O₃/Al复合涂层有效地抑制了O_2-,S_-和Na₊对基体γ-TiAl合金的侵蚀。并且,Al₂O₃/Al复合涂层的梯度结构亦使其表现出了优异的抗开裂和抗剥落性能。     

大气等离子喷涂TiB2-316L不锈钢基复合涂层及其耐磨性能

分别采用高能球磨制备了TiB2含量(质量分数)为10%的316L不锈钢基复合粉,高能球磨与喷雾干燥造粒工艺制备了TiB2含量(质量分数)为40%的316L不锈钢基复合粉,大气等离子喷涂制备相应的TiB2-316L不锈钢基金属陶瓷涂层与316L不锈钢涂层.室温下采用高速环块磨损试验研究TiB2-316L不锈钢基金属陶瓷涂层的磨损特性.采用X射线衍射分析涂层物相,扫描电镜分析喷涂粉末、涂层结构和摩擦副磨损表面形貌.结果表明,大气等离子喷涂两种制粉工艺获得的316L不锈钢基TiB2复合粉能获得较耐磨的316L不锈钢基TiB2复合涂层,耐磨性高于316L不锈钢涂层,且TiB2在复合涂层中增强涂层耐磨性的原因是TiB2颗粒在涂层316L韧性基体中充当强化相,且TiB2在摩擦接触处摩擦氧化形成的氧化产物具有自润滑特性,能减少涂层的磨损量.     

TiN-TiB2 composite coatings reactively produced by electrothermally exploded powder spray

Composite coatings composed of titanium nitride, TiN, and diboride, TiB₂, were reactively produced by the electrothermally exploded powder spray technique, in which feedstock powder was prepared from titanium and boron nitride particles. The microstructure of the coating was composed of titanium-ceramic particles the size of which were on the order of several nanometers to a few hundred nanometers. Such reactive thermal spraying brought base-metal saturation into a coating layer at the early stages of coating formation. The ceramic composite spray using feedstock of TiN and TiB₂ particles preferentially brought a new phase of cubic titanium boronitride together with TiN and TiB₂ into a coating. On comparing such a coating to one produced by the conventional method, the reactive thermal spray coating was richer in TiN and TiB₂ due to the excess nitrogen in the feedstock.     

激光原位合成TiB2-TiC颗粒增强铁基涂层

采用B4C,TiO2,石墨以及铁基粉末为激光熔覆材料,利用激光多道搭接熔覆技术在碳钢基体上制备TiB2-TiC颗粒增强铁基复合涂层．利用XRD,SEM对涂层的相结构和显微组织进行了研究．采用显微硬度计和滑动磨损试验机分别测试了涂层的硬度和耐磨性能．结果表明,激光熔覆过程B4C,TiO2和石墨反应生成了TiB2和TiC颗粒,并均匀分布在基体中．随着激光功率密度增加,涂层中TiC含量减少,甚至出现FeB脆性相．TiB2-TiC颗粒增强的涂层其硬度和耐磨性能优于基材45钢．     

TIG熔覆原位自生TiC-TiB2/Fe复合涂层

利用氩弧作为热源,以G302铁基合金粉、FeTi70粉和B₄C粉作为原料粉末,在Q235表面原位生成TiC-TiB₂增强的铁基复合涂层. 采用一系列的分析测试方法对涂层进行了表征,结果表明,氩弧熔覆过程冶金反应充分,熔覆层中生成了TiC,TiB₂和M₇C₃等硬质增强相;熔覆层组织呈现出由母材界面到熔覆层表面硬质相逐渐增多的梯度分布特征. 增加FeTi70和B₄C粉末比例提高了熔覆层硬度,质量比为G302:FeTi70:B₄C=6:3:1时,试样最大硬度达到976 HV0.1,是母材硬度的5倍左右. 在与GCr15钢对磨时,熔覆试样磨损量仅为Q235钢的1/30左右,熔覆层磨损表面基本无塑性变形痕迹,涂层中坚硬的TiC,TiB₂陶瓷相起到阻磨作用.     

Self‐healing properties of TiO2 particle–polymer composite coatings for protection of aluminum alloys against corrosion in seawater

TiO₂ particle–polymer composite coatings were applied to the surface of a 5083 aluminum alloy. After using a knife to create an artificial defect, polarization resistance was monitored in artificial seawater at a temperature of 30 °C. The polarization resistance of the specimen coated with the composite polymer containing 3 vol% TiO₂ particles increased significantly over time, suggesting that the composite coating had self‐healing properties. A carbon‐containing 2‐µm thick film was found on the coated aluminum substrate at the site of the artificial defect. The formation of the film was related to the dissolution of bisphenol A (BPA), which is a chemical precursor of the polymer coating that behaved as an inhibiting agent.     

TiB2陶瓷颗粒增强的金属基复合涂层

采用电弧喷涂制备TiB2陶瓷颗粒增强的NiCr-TiB2,NiCr-TiB2/Al2O3和304L-TiB2及304L-TiB2/Al2O3四种金属基复合涂层.采用光学显微镜、扫描电子显微镜(SEM)结合透射电子显微镜(TEM)观察和详细分析了TiB2陶瓷颗粒增强复合涂层的显微组织及微观结构,探讨涂层的形成机理.结果表...     

Fabrication and Properties of Thermal Sprayed AlSi-Based Coatings from Nanocomposite Powders

AlSi-based nanocomposite powders (where nanoparticles were TiO₂, ZrO₂, and Al₂O₃ and the amount of reinforcement was 2.5, 5, and 10 wt.%) were made by ball milling and then thermal sprayed using low velocity oxy-fuel technique. The AlSi-based nanocomposite powders had nanosized ceramic reinforcement adhered to the surface of the powders after ball milling. The AlSi-based coatings had the typical thermal spray microstructure where lamellae, oxide layers, unmelted particles, and pores could be seen. Submicron second phase in the form of agglomerates, molten splats, or unmelted particles between AlSi lamellae could be observed as well. Hardness and porosity of the coatings increased when more ceramic second phase particles (harder than AlSi) were added. Sliding wear tests were carried out in pin-on-disk geometry. The wear tracks of AlSi and AlSi-based coatings show plastic deformation as the main material removal mechanism during the sliding wear test. The sliding wear rate of the coatings decreased as more second phase ceramic particles were added. It was due to an increase in the hardness and a decrease in the friction coefficient of the coatings.     

Performance evaluation of laser surface alloyed hard nanostructured Al2O3-TiB2-TiN composite coatings with in-situ and ex-situ reinforcements

Hard and wear resistant Al₂O₃-TiB₂-TiN composite coatings have been developed on low carbon steel (AISI 1025) substrate by following two different routes involving laser surface treatment. In the first (termed ‘in-situ’ process), reinforcing phases TiB₂ and TiN, as well as the matrix Al₂O₃ of the composite are synthesized in-situ by laser-triggered self-propagating high temperature synthesis (SHS) from a mixture of Al, TiO₂ and h-BN and coated onto the substrate surface by laser surface alloying (LSA). In the second (termed ‘ex-situ’ process), the constituents Al₂O₃, TiB₂ and TiN of the coating are provided directly as a pre-placed precursor powder mix and laser surface alloyed onto the substrate. Of these two laser assisted manufacturing procedures, it is of interest to determine the one that is more appropriate for the development of a hard, wear resistant coating. In the present work, investigation of the comparative merits and demerits of Al₂O₃-TiB₂-TiN coatings produced by in-situ and ex-situ processes is attempted through analysis of microstructure and evaluation of mechanical and tribological properties.     

The study of NiAl-TiB2 coatings prepared by electro-thermal explosion ultrahigh speed spraying technology

NiAl-TiB₂ composite coatings with 0, 10 and 20 wt.% TiB₂ were synthesized on the Ni-based superalloy substrate using electro-thermal explosion ultrahigh speed spraying technology. The microstructure analysis shows that the coatings consist of submicron grains. The bond between coatings and substrate is metallic cohesion. TiB₂ as a powerful reinforcement is doped in NiAl for increasing its hardness. The isothermal oxidation test is carried out for the composite coatings at 1100 °C in air. The result shows that the oxidation resistance of NiAl coating is higher than that of NiAl-10TiB₂ and NiAl-20TiB₂ coatings. The phases of oxides on the coatings during the process at high temperature have been analyzed by X-ray diffraction. The results show that Al₂O₃ and Cr₂O₃ coexistence on surface of NiAl coating, while Al₂O₃, Cr₂O₃, TiO₂ and a small amount of NiO form on surface of NiAl-10TiB₂ and NiAl-20TiB₂ coatings after oxidation for 4 h.     

激光熔覆B4C-TiO2-Al粉末制备原位TiB2+TiC/Fe复合涂层（英文）

采用B4C、TiO2、Al以及Fe基自熔合金粉末为前驱体,利用激光熔覆技术在钢基体上制备TiB2+TiC颗粒增强Fe基复合涂层。结果表明,激光熔覆过程通过B4C-TiO2-Al反应生成了均匀分布于基体的TiB2-TiC复合陶瓷相。TiB2颗粒呈长条块状,TiC以不规则形状分布于基体中。涂层具有比基材1045钢更好的耐磨性能,但涂层的摩擦因数小。