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《材料热处理学报》2015,(12)
采用放电等离子烧结制备了GNP(石墨烯)/3Y-TZP复合陶瓷材料。研究了石墨烯含量对GNP/3Y-TZP复合材料微观结构与性能的影响规律。结果表明,石墨烯经过高温高压烧结后仍保持原有结构,并且复合材料断口处有明显的石墨烯片层拔出;石墨烯增强相与氧化锆基体之间形成了适中的界面结合强度。当石墨烯含量增加至1%时,材料断裂韧性从7.4 MPa·m~(1/2)提高到8.6 MPa·m~(1/2);当石墨烯含量达到1.5%时,过多石墨烯导致复合陶瓷中孔隙增加,使复合材料韧性下降。对GNP/3Y-TZP复合材料进行老化试验表明,石墨烯引入可有效抑制GNP/3Y-TZP复合材料中四方氧化锆到单斜氧化锆的相变。 相似文献
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In this work, 60 wt.% NiCrSiB–40 wt.% Al2O3 composite coating was produced on AISI 304 substrate material using the atmospheric plasma spraying technique. The coating surface has been characterised using a scanning electron microscope (SEM), optical microscope and X-ray diffractometer (XRD). The microhardness, porosity, density and surface roughness of the coating were measured. The adhesion strength of the coating was measured using pull off adhesion tester. The erosion behaviour of plasma sprayed coating was studied at 450 °C using hot air jet erosion testing machine. The erosion rate of coated and uncoated samples was evaluated at 30° and 90° erodent impact angles. The SEM images of the eroded samples were taken to analyse the erosion mechanism. The test results reveal that the coating protects the substrate at both 30° and 90° impact angles. 相似文献
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Al2O3–10TiC composite was synthesized by high energy ball milling followed by spark plasma sintering (SPS) process. Microstructure of the sintered composite samples reveals homogeneous distribution of the TiC particles in Al2O3 matrix. Effect of sintering temperature on the microstructure and mechanical properties was studied. The sample sintered at 1500 °C shows a measured density of 99.97% of their theoretical density and hardness of 1892 Hv with very high scratch resistance. These results demonstrate that powder metallurgy combined with spark plasma sintering is a suitable method for the production of Al2O3–10TiC composites. 相似文献
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放电等离子烧结制备超细WC基硬质合金 总被引:1,自引:0,他引:1
采用纳米碳化钒(V8C7)粉末作为晶粒抑制剂及放电等离子烧结(SPS)方式制备超细WC基硬质合金.X射线衍射结果表明:超细WC基硬质合金主要由WC和Co3C两相组成,随着温度的升高,WC的衍射峰逐渐向小角度偏移.扫描电镜结果表明:SPS和纳米V8C7粉末对超细WC基硬质合金的微观组织具有重要影响.SPS使超细WC基硬质合金在较低温度下(1200℃)实现致密化;纳米V8C7粉末可以有效抑制超细WC基硬质合金中WC的晶粒长大,1200℃时WC的晶粒尺寸约500 nm.力学性能结果表明:1200℃时超细WC基硬质合金具有较高的性能(相对密度99.5%,洛氏硬度93.2,断裂韧性12.5 MPa·m1/2). 相似文献
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SiC/MoSi2 composites were synthesized at different temperatures by spark plasma sintering using Mo, Si and SiC powders as raw materials. The phase composition, microstructure and mechanical properties of the as-prepared composites were investigated and the sintering behavior was also discussed. Results show that SiC/MoSi2 composites are composed of MoSi2, SiC and trace amount of Mo4.8Si3C0.6 phase and exhibit a fine-grain texture. During the synthesis process, there was an evolution from solid phase sintering to liquid phase sintering. When sintered at 1600 °C, the SiC/MoSi2 composites present the most favorable mechanical properties, the Vickers hardness, bending strength and fracture toughness are 13.4 GPa, 674 MPa and 5.1 MPa·m1/2, respectively, higher 44%, 171%, 82% than those of monolithic MoSi2. SiC can withstand the applied stress as hard phase and retard the rapid propagation of cracks as second phase, which are beneficial to the improved mechanical properties of SiC/MoSi2 composites. 相似文献
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Microstructure and mechanical properties of Al2O3/TiAl composite 总被引:4,自引:1,他引:4
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This study investigates how the partial replacement of Co with Al2O3 ceramic binder has an effect on the sintering behaviour, microstructure, and final mechanical properties of WC-Co cermets via spark plasma sintering. To examine this, three batches (WC-6 wt%Co, WC-3 wt%Co-3 wt%Al2O3, and WC-6 wt%Al2O3) were mixed through high energy ball mill, and sintering was carried out at temperatures of 1350 °C and 1600 °C. The results showed nearly full dense WC-Co cermets at different temperatures. It was shown that WC-6 wt%Al2O3, in comparison to reference WC-6 wt%Co cermet, not only led to the rise in sintering temperature from 1350 °C to 1600 °C, but also reduced its strength and toughness. But replacing some part of Co with alumina (WC-3 wt%Co-3 wt%Al2O3) exhibited the combination of high strength (1095 MPa), hardness (17.62 GPa), and fracture toughness (19.46 MPa·m1/2). 相似文献
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等离子电火花烧结TiAl-Nb复合材料的显微组织与断裂韧性(英文) 总被引:1,自引:0,他引:1
将钛铝预合金粉末和铌粉按照摩尔比9:1混合均匀,再采用等离子电火花烧结技术在1250°C、50MPa下烧结5min制备细晶钛铝基复合材料。采用X射线衍射、电子扫描、透射以及电子探针探讨烧结样品中显微组织、相成分的分布及晶粒度。结果表明:合金的显微组织主要由大量的层片γ相、O相、Nbss(Nb固溶相)以及B2相组成;室温烧结样品的断裂韧性高达28.7MPa·m1/2,韧性铌固溶相在裂纹尖端以塑性延伸的方式吸收断裂能,从而提高了合金的断裂韧性;B2相以也会促进裂纹的侨联和分叉。对合金各相的显微硬度也进行了测试。 相似文献
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Spark plasma sintering (SPS) is one of the methods used to achieve the low-temperature densification of refractory metal materials. In this study, powder prepared through a wet chemical method was consolidated via SPS at 1100 °C, 1200 °C, 1350 °C, 1600 °C, and 1800 °C to obtain a high-performance W-TiC-Y2O3 composite material. Densification was studied by analyzing the densification curve and changes in the microstructure of the samples. This process could be divided into three stages: the bonding stage, the sintering neck growth stage, and the shrinkage and spherification stage of closed pores. Surface diffusion and grain boundary diffusion played different roles in densification. The density, grain size, and Vickers hardness of the tungsten material increased significantly as temperature increased. This study evaluated the sintering process and provided a basis for obtaining high-performance tungsten materials through SPS. 相似文献
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采用放电等离子体烧结(SPS)工艺在610℃制备30%~50%(质量分数)纳米石墨片(GNF)/6061Al基复合材料,研究烧结压力及GNF含量对复合材料显微组织和力学、热学性能的影响.结果表明,SPS有效抑制GNFs/6061Al基复合材料中Al4C3等界面反应产物的生成.随着GNF含量的增加,GNFs团聚程度增加,... 相似文献
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B4C-TiB2 composite ceramic was prepared by reactive spark plasma sintering, using amorphous B, Ti, and graphite as the raw materials. The reaction process and the phase composition in the process of sintering were studied. The effects of the ratio of raw materials and sintering process on the microstructure and mechanical properties of B4C-TiB2 composite ceramic were investigated. The composition of the sintered sample was B4C, TiB2, and bits of residual unreacted graphite. B and Ti preferentially reacted to form TiB2 at 800 °C, and then B and graphite reacted to form B4C at 1250 °C. The 75 vol% B4C-25 vol% TiB2 composite ceramic synthesized with 60.6 wt% B, 25.8 wt% Ti, and 13.6 wt% graphite and sintered at 1900 °C for 15 min resulted in nearly full densification and optimal mechanical properties. The relative density, Vickers hardness, fracture toughness, and flexural strength were 98.6 ± 0.01%, 26.6 ± 0.01 GPa, 5.9 ± 0.13 MPa·m1/2, and 605 MPa, respectively. 相似文献
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Small amounts of nanocrystalline Al2O3 particles were doped in WC-Co nanocrystalline powders to study their reinforcing effects, and spark plasma sintering technique was used to fabricate the WC-Co-Al2O3 nanocomposites. Experimental results show that the use of Al2O3 nanoparticles as dispersions to reinforce WC-Co composites can increase the hardness, especially the transverse rupture strength of the WC-Co hardmetal. With addition of 0.5%(mass fraction) Al2O3 nanoparticles, the spark plasma sintered WC-TCo-0. 5Al2O3 nanocomposites exhibit hardness of 21.22 GPa and transverse rupture strength of 3 548 MPa. The fracture surface of the WC-TCo-0.5Al2O3 nanocomposites mainly fracture with transcrystalline rupture mode. The reinforcing mechanism is maybe related to the hindrance effect of microcracks propagation and the pinning effect for the dislocations movement, as well as the residual compressive strength due to the Al2O3 nanoparticles doped. 相似文献
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In the present study, the reciprocating wear behavior of 7075Al/SiC composites and 6061Al/Al2O3 composites that are prepared through liquid metallurgy route is analyzed to find out the effects of weight percentage of reinforcement and load at the fixed number of strokes on a reciprocating wear testing machine. The Metal Matrix Composite (MMC) pins are prepared with different weight percentages (10, 15 and 20%) of SiC and Al2O3 particles with size of 36 μm. Hardness of these composites increases with increase in wt.% of reinforcement. However, the impact strength decreases with increase in reinforcement content. The experimental result shows that the volume loss of MMC specimens is less than that of the matrix alloy. However, the volume loss is greater in 6061Al/Al2O3 composites when compared to 7075Al/SiC composites. The temperature rise near the contact surface of the MMC specimens increases with increase in wt.% of reinforcement and applied load. The coefficient of friction decreases with increase in load in both cases. 相似文献
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JIAXian LINGXiaomei 《稀有金属(英文版)》2004,23(1):59-63
The abrasive wear characteristics of Al2O3/PA1010 composite coatings on the surface of quenched and low-temperature temper steel 45 were tested on the tumplate abrasive wear testing machine and the same uncoated steel 45 was used as a reference material. Experimental results showed that the abrasive wear resistance of Al2O3/PA 1010 composite coatings has a good linear relationship with the volume fraction of Al2O3 particles in Al2O3/PA1010 composite coatings, and the linear correlative coefficient is 0.979. Under the experimental conditions, the size of Al2O3 particles (40.5-161.0μm) has little influence on the abrasive wear resistance of Al2O3/PA1010 composite coatings. By treating the surface of Al2O3 parti-cles with a suitable bonding agent, the distribution of Al2O3 particles in matrix PA1010 is more homogeneous and the bonding state between Al2O3 particles and matrix PA1010 is better. Therefore, the Al2O3 particles in Al2O3/PA1010 compos-ite coatings make the Al2O3/PA1010 composite coatings have better abrasive wear resistance than PA1010 coatings. The wear resistance of Al2O3/PA1010 composite coatings is about 45% compared with that of steel 45. 相似文献
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Peng-Yue Gao Yu-Duo Ma Wen-Wei Sun Yong Yang Chen Zhang Yu-Hang Cui Yan-Wei Wang Yan-Chun Dong 《稀有金属(英文版)》2021,(7):1825-1834
Al2O3-ZrO2-TiO2 coatings were successfully prepared by plasma spraying Al2O3-ZrO2 composite powders with and without TiO2 addition.The effects of TiO2 on the ph... 相似文献
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纳米掺杂Al2O3/ZrO2等离子喷涂涂层的组织及性能 总被引:1,自引:0,他引:1
利用自行研制的纳米掺杂AZ-20热喷涂粉末,采用大气等离子喷涂技术,在35号钢基体上制备A12O3/ZrO2复合材料热障涂层,对涂层的组织结构及性能进行分析。结果表明:制备的涂层是由四方结构的t'=ZrO2与六方结构的α-A12O3构成的,具有纳米晶与微米晶混晶组织;涂层孔隙率为11.2%,孔隙尺度较均匀:涂层硬度HV100为702,抗磨损能力较常规AZ-20涂层高约25%:涂层具有良好的隔热性能。 相似文献