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纯铜热化学反应热喷涂陶瓷/渗铝复合涂层耐蚀性研究 总被引:1,自引:1,他引:0
采用火焰喷涂技术在铜基体表面先后喷涂渗铝层和陶瓷涂层,并加热保温,制备成铜基陶瓷/渗铝复合涂层。用XRD和SEM对涂层进行组织结构分析和形貌观察,并测试涂层的硬度、抗热震性和耐蚀性。结果表明,复合涂层中有Cu9Al4、Cu5Zn8、Cu3Ti等新相生成;渗铝层部分有γ2相(Cu9Al4)析出且涂层与基体结合紧密;复合涂层的硬度为82~87 HRE,其耐热震次数可达50次以上;复合涂层封孔后的耐酸蚀能力提高到基体的16倍,耐盐蚀能力提高到基体的25倍;极化试验表明,复合涂层抗电化学腐蚀能力显著增强,其耐蚀性能远优于纯铜渗铝层和单纯陶瓷涂层。 相似文献
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AZ31B镁合金表面SHS反应热喷涂复相陶瓷涂层的制备及性能 总被引:1,自引:1,他引:0
采用SHS反应火焰喷涂技术,把Al-TiO2-B2O3铝热反应剂引入喷涂材料中,采用机械球磨和聚乙烯醇(PVA)造粒制成喷涂复合粉末,在镁合金AZ31B表面制备Al2O3基复相陶瓷涂层.利用XRD和SEM分析了喷涂复合粉末和复合陶瓷涂层的组成及形貌,并对涂层的热震性能、致密性、显微硬度和耐磨性进行测试.结果表明:复合粉末经12 h球磨后发生铝热反应,粉末呈球形及少量片状,造粒后形成相互包覆的球形结构.涂层中生成TiB2、MgAl2O4等新相.该复合涂层熔化较充分,涂层与基体结合紧密,界面处Mg元素有扩散.复合涂层热震次数可达45次,清漆封孔后,孔隙率为0%,致密性很好,最大显微硬度值达1224 HV0.1,耐磨性比镁合金基体提高8倍以上.涂层热震性能、致密性、显微硬度和耐磨性明显优于普通热喷涂陶瓷涂层. 相似文献
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采用相同的陶瓷骨料和热喷涂工艺,放热体系分别为Al/CuO和Al-TiO2-B2O3,制备热喷涂陶瓷涂层,通过对涂层表面形貌观察、物相分析、孔隙率,耐酸性(5%醋酸),耐盐性(3.5%NaCl)测试比较放热体系对陶瓷涂层耐蚀性能影响。结果表明:与基体AZ31B相比,采用Al-CuO为放热体系的陶瓷涂层耐酸性提高23.37倍,耐盐性提高16.33倍,Al-TiO2-B2O3放热体系陶瓷涂层的耐酸性提高12.91倍,耐盐性提高7.46倍,Al-CuO放热体系陶瓷涂层耐蚀性优于Al-TiO2-B2O3放热体系陶瓷涂层。 相似文献
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选用常规微米尺度Al2O3粉体和纳米结构Al2O3-TiO2粉体作为硬质颗粒,采用等离子喷涂方法在45钢基体上制备了Al2O3/Al2O3-TiO2颗粒增强铝基复合涂层,采用扫描电镜(SEM)、X射线衍射仪(XRD)和维氏硬度计观察和测试涂层的形貌、物相及显微硬度,通过滑动摩擦磨损试验分析涂层的摩擦学性能。结果显示,Al/Al2O3涂层的表面形貌和纯铝涂层非常相似,Al/Al2O3-TiO2涂层表面可以看到未熔、半熔和全熔的增强相存在。Al/Al2O3涂层的主要物相为Al和α-Al2O3,Al/Al2O3-TiO2涂层的主要物相为Al、α-Al2O3和TiO。随着增强相加入量的提高,Al/Al2O3涂层和Al/Al2O3-TiO2涂层的硬度不断提高;当添加量为30%时,硬度分别比未加增强相时提高了67%和76%。加入增强相的涂层的平均摩擦因数都有较大幅度的减小,加入30%Al2O3的Al/Al2O3涂层的磨损量比未加入增强相涂层的磨损量下降85.6%,Al/Al2O3-TiO2涂层的磨损量比未加入增强相涂层的磨损量下降74%左右,表明硬质颗粒Al2O3和Al2O3-TiO2的加入,可显著提高涂层的耐磨性。 相似文献
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热喷涂合成Fe3Al基涂层的高温摩擦学特性 总被引:2,自引:0,他引:2
采用自制的新型热喷涂粉芯丝材和高速电弧喷涂技术成功制备出Fe3Al金属化合物基合金涂层,对涂层的组织、成分和相结构进行了初步分析,并测试了涂层在室温至650℃的摩擦学特性。结果表明:Fe3Al涂层的基体相由含29%Al(摩尔分数)的Fe3Al和FeAl二相混合物组成,Fe3Al/WC涂层基体为Fe-26%Al(摩尔分数)合金;添加少量WC硬质相的Fe3Al/WC涂层具有良好的高温减摩特性和耐磨性,450℃和650℃其相对耐磨性分别比20g钢高1.92倍和9.23倍;WC/W2C硬质相对Fe3Al基体的强化作用,以及涂层表面形成具有自保护作用的高硬度致密氧化膜是Fe3Al/WC涂层高温耐磨性提高的主要原因。 相似文献
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采用膏剂法及加热扩散在纯铜表面制备铜基陶瓷/渗铝复合涂层。观察分析了复合涂层的形貌和结构,并研究了该复合涂层的抗热震性能、涂层硬度、耐磨性。结果表明:纯铜膏剂法热化学反应陶瓷/渗铝复合涂层中有Na7Al3O8、Cu3TiO4、Cu9Al4等新相生成;复合涂层在700℃条件下热震次数可达40次以上;复合涂层的硬度可达83.8 HRE,耐磨性实验中,复合陶瓷涂层的相对耐磨性是基体的5.40倍;复合陶瓷涂层的黏着磨损(干摩擦)相对耐磨性是基体的5.64倍;复合陶瓷涂层的黏着磨损(油摩擦)相对耐磨性是基体的10.14倍。 相似文献
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采用热化学反应法在MB2镁合金表面制备了含纳米Al2O3粒子的陶瓷涂层,研究了涂层的耐磨性、测试了涂层的耐热冲击性,并采用XRD分析其相结构.结果表明,含纳米Al2O3粒子陶瓷涂层的耐热冲击性优异,耐磨性相对于基体显著提高;含纳米Al2O3粒子的涂层中含有新相Mg2SiO4和Al2SiO5、ZnAl2O4及MgMnSiO4. 相似文献
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Helmi Abdelkefi Hamadi Khemakhem Annie Simon Jacques Darriet 《Journal of Alloys and Compounds》2008,463(1-2):423-427
The Ba0.985Na0.015Ti0.985Nb0.015O3, Ba0.6Na0.4Ti0.6Nb0.4O3 and Ba0.3Na0.7Ti0.3Nb0.7O3 compositions of the (1 − x) BaTiO3–xNaNbO3 (BTNNx) system have been studied by X-ray diffraction and by measurements of dielectric properties. The specimens with composition BTNN (x = 0.015, 0.40 and 0.70) have been refined by the JANA program from X-ray powder diffraction data. Ceramic samples with composition (1 − x) BaTiO3 + xNaNbO3 (where x = 0.015, 0.40 and 0.70) were prepared by calcinations from appropriate mixture of BaCO3, TiO2, Na2CO3 and Nb2O5. The calcined powder was sintered at temperature range 1200–1400 °C. As the composition x increased from 0.015 (and 0.70), the ferroelectric ceramics (x = 0.015, FE) with tetragonal phase changed to the ferroelectric relaxors (RFE, x = 0.40). RFE ceramics showed a peculiar diffuse phase transition and dielectric relaxation at the low temperature (down to 180 K) due to a frustration between RFE and FE state. These ceramics present the classical ferroelectric character when 0 ≤ x < 0.075 and 0.55 < x ≤ 1 and relaxor character when 0.075 ≤ x ≤ 0.55. 相似文献
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Z. Stok?osa J. RasekP. Kwapuliński G. BaduraG. Haneczok L. Paj?kJ. Lel?tko A. Kolano-Burian 《Journal of Alloys and Compounds》2011,509(37):9050-9054
Influence of 1 h annealing in vacuum on magnetic, electrical and plastic properties of Fe76Nb2Si13B9, Fe75Ag1Nb2Si13B9 and Fe75Cu1Nb2Si13B9 melt spun ribbons were carefully investigated. It was shown that in all cases soft magnetic properties can be significantly enhanced by applying 1-h annealing at characteristic temperatures Top. This optimization annealing causes that permeability increases more than 15-times and magnetic losses (tangent of loss angle) achieves a minimum in relation to the as quenched state. Using structural examinations (X-ray and HRTEM) it was shown that for the Fe75Cu1Nb2Si13B9 alloy the optimized microstructure corresponds to a nanocrystalline αFe(Si) phase whereas in other alloys to a relaxed amorphous phase free of iron nanograins. As a consequence of this fact the Fe76Nb2Si13B9 and Fe75Ag1Nb2Si13B9 alloys show higher plasticity in comparison to the nanocrystalline Fe75Cu1Nb2Si13B9 alloy. Temperatures of the first stage of crystallization, and related diffusion parameters were determined using measurements of resistivity versus temperature with different heating rates. 相似文献
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针对草酸盐配位共沉淀热分解还原法制备超细铁镍合金粉过程中Fe2+-Ni2+-NH3-NH4+-C2O42--H2O体系的溶液平衡建立热力学分析模型,并根据模型进行相关计算,揭示反应体系中各物质随pH值、氨及草酸浓度的变化关系。结果表明:溶液中的Fe主要以[Fe(C2O4)n]2 2n络合物形式存在,而铁氨络合物含量很低。当氨含量较低时,溶液中的Ni主要以[Ni(C2O4)n]2 2n存在;氨含量较高时,在酸性条件下,溶液中的Ni主要以[Ni(C2O4)n]2 2n存在,在碱性条件下,则主要以[Ni(NH3)n]2+存在。低pH值下,Ni的沉淀率较Fe的高,而高pH值下,Ni的沉淀率则较Fe的低。 相似文献
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采用溶胶-凝胶法和低温燃烧技术制备Ce1-xSmxO2(x=0,0.1,0.2,0.3)和掺杂Sm和(2%-8%)Al2O3的二氧化铈;研究其合成、结构、致密化、导电性和热膨胀等性能,并利用XRD研究其结构和相组成。结果表明,于1300°C烧结球团,获得致密的陶瓷,于1250°C在Ce0.8Sm0.2O0.2中加入2%和4%的Al2O3以促进烧结。利用扫描电子显微镜观察烧结后球团的表面形貌,使用双探针交流阻抗谱研究总离子电导率。 相似文献
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G. Q. Liu L. Wen G. Y. Liu H. Z. Luo B. Y. Ma Q. Y. Wu Y. W. Tian 《Metals and Materials International》2011,17(4):661-664
Spinel compound LiNi0.4Mn1.5Cr0.1O4 (LNMCO) and Li4Ti5O12 (LTO) were synthesized by the sol-gel method and the solid-state method, respectively. The particle sizes of the products
LiNi0.4Mn1.5Cr0.1O4 and Li4Ti5O12 were 0.5 to 2 um and 0.5 to 0.8 um, respectively. All samples exhibited excellent electrochemical properties. A LiNi0.4Mn1.5Cr0.1O4/Li4Ti5O12 (LNMCO/LTO) cell was fabricated and was demonstrated to exhibit good electrochemical properties at the high current rate
of 1 C. When the specific capacity was determined based on the mass of the LNMCO cathode, the LNMCO/LTO cell delivered 125
mAh g−1 at 1 C and 77 mAh g−1 at 5 C. The capacity retentions after 30 cycles were 94.4 % and 83.1 %, respectively. 相似文献
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Sinterability and dielectric properties of Ba0.55Sr0.4Ca0.05TiO3-CaTiSiO5-Mg2TiO4 composite ceramics
Qianqian JiaHuiming Ji Xiaolei LiShan Liu Zhengguo Jin 《Journal of Alloys and Compounds》2011,509(41):10155-10160
The composite ceramics of Ba0.55Sr0.4Ca0.05TiO3-CaTiSiO5-Mg2TiO4 (BSCT-CTS-MT) were prepared by the conventional solid-state route. The sintering performance, phase structures, morphologies, and dielectric properties of the composite ceramics were investigated. The BSCT-CTS-MT ceramics were sintered at 1100 °C and possessed dense microstructure. The dielectric constant was tailored from 1196 to 141 as the amount of Mg2TiO4 increased from 0 to 50 wt%. The dielectric constant and dielectric loss of 40 wt% Ba0.55Sr0.4Ca0.05TiO3-10 wt% CaTiSiO5-50 wt% Mg2TiO4 was 141 and 0.0020, respectively, and the tunability was 8.64% under a DC electric field of 8.0 kV/cm. The Curie peaks were broadened and depressed after the addition of CaTiSiO5. The optimistic dielectric properties made it a promising candidate for the application of tunable capacitors and phase shifters. 相似文献
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M. Hoch 《Journal of Phase Equilibria and Diffusion》1996,17(4):290-301
We applied our model to the enthalpy of mixing data of the binary systems Na2O-SiO2, Na2O-GeO2, Na2O-B2O3, Li2O-B2O3, CaO-B2O3, SrO-B2O3, and BaO-B2O3. The most stable composition in the liquid, that is where the enthalpy of mixing is most negative, is with a metal-oxygen
ratio of 4 to 3, for monovalent metals (Na and Li) and 3 to 4 for divalent metals (Ba and Ca) in liquid silicates or borates.
The same applies to the CaO-SiO2, CaO-Al2O3, PbO-B2O3, PbO-SiO2, ZnO-B2O3, and ZnO-SiO2 systems. The oxygen to metal ratio, its constant value in various types of systems, reflects and describes the structure
of the liquid.
Using the analyzed enthalpies of mixing data and the available phase diagrams, we calculated the enthalpies of formation of
the various binary compounds. The results are in excellent agreement with data in the literature that were obtained from direct
solid-solid calorimetry. 相似文献
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Feng Gao Liangliang LiuBei Xu Xiao CaoZhenqi Deng Changsheng Tian 《Journal of Alloys and Compounds》2011,509(20):6049-6055
Plate-like NaNbO3 (NN) particles were used as the raw material to fabricate (1 − x)[0.93 K0.48Na0.52Nb O3-0.07Li(Ta0.5Nb0.5)O3]-xNaNbO3 lead-free piezoelectric ceramics using a conventional ceramic process. The effects of NN on the crystal structure and piezoelectric properties of the ceramics were investigated. The results of X-ray diffraction suggest that the perovskite phase coexists with the K3Li2Nb5O15 phase, and the tilting of the oxygen octahedron is probably responsible for the evolution of the tungsten-bronze-typed K3Li2Nb5O15 phase. The Curie temperature (TC) is shifted to lower temperature with increasing NN content. (1 − x)[0.93 K0.48Na0.52NbO3-0.07Li(Ta0.5Nb0.5)O3]-xNaNbO3 ceramics show obvious dielectric relaxor characteristics for x > 0.03, and the relaxor behavior of ceramics is strengthened by increasing NN content. Both the electromechanical coupling factor (kp) and the piezoelectric constant (d33) decrease with increasing amounts of NN. 0.01-0.03 mol of plate-like NaNbO3 in 0.93 K0.48Na0.52NbO3-0.07Li(Ta0.5Nb0.5)O3 gives the optimum content for preparing textured ceramics by the RTGG method. 相似文献