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1.
采用热压烧结工艺制备了AIN-TiB,复合材料.通过XRD、SEM和激光导热仪研究了TiB2含量和烧结温度对材料导热性能的影响.结果表明:随着TiB2含量的增加,复合材料的热导率逐渐下降,当TiB2含量增至50%时,热导率由102.9W/(m·K)下降到36.6 W/(m·K).另外,在TiB2含量10%时,随着烧结温度的升高,热导率呈逐渐上升的趋势.并对A1N-TiB2的相组成和显微结构进行了观察分析. 相似文献
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采用热压烧结工艺制备了AlN-TiB2复合材料。通过XRD、SEM和激光导热仪研究了TiB2含量和烧结温度对材料导热性能的影响。结果表明:随着TiB2含量的增加,复合材料的热导率逐渐下降,当TiB2含量增至50%时,热导率由102.9 W/(m.K)下降到36.6 W/(m.K)。另外,在TiB2含量10%时,随着烧结温度的升高,热导率呈逐渐上升的趋势。并对A1N-TiB2的相组成和显微结构进行了观察分析。 相似文献
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研究了影响Sialon结合BN材料致密化的工艺参数.试验结果表明:BN含量是影响合成材料致密化的主要因素,BN含量越高,合成材料越难致密化;添加Y2O3可以显著地促进合成材料的致密化,合适的Y2O3加入量是材料中ω(Y2O3)达到4%~5%. 相似文献
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黄泽培 《粉末冶金材料科学与工程》1998,(3)
系统地讨论了两种不同的烧结方法对(α+β)-Sialon系统相形成、显微结构及性能的影响。实验结果表明:同样的烧结参数,热压烧结制备的(α+β)-Sialon具有较好的显微结构和强度,这是由于外加推动力加速了材料的烧结过程,提高了致密度,因而提高了材料性能。讨论了温度、时间和加热速率的影响。结果表明:最适宜的无压烧结和热压烧结温度分别为1750~1800℃和1700~1750℃,烧结时间分别为120 min和60 min。两种烧结方法的最佳升温速率均为15~20℃/min。 相似文献
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以原位还原所得超细WC-6%Co复合粉为原料,研究了热压烧结制备硬质合金材料的工艺过程,并分析了材料的物理性能及力学性能。结果表明:将平均粒径约300nm的超细WC-Co复合粉在热压炉中于1 370℃烧结1.5h,可得到平均晶粒度为600nm、相对密度99%且具有良好综合力学性能的亚微米WC-Co硬质合金。 相似文献
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通过真空热压烧结制备30%(体积分数)SiCp/2024Al复合材料,采用分离式霍普金森压杆(SHPB)对其进行动态压缩实验,得到应变速率为1 600~3 800 s-1的动态应力-应变曲线.结果表明:在一定的高应变率范围内承受动态载荷时,30%SiCp/2024Al复合材料在不同应变率下,应力-应变曲线趋势变化不大,... 相似文献
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采用热等静压法制备铝基碳化硼复合材料(Al-B4C)板材,测试板材的密度和抗拉强度,并观察复合材料的微观组织和拉伸断口形貌。结果表明,Al-31%B4C(质量分数)板材的尺寸为3 mm×200 mm×5000 mm;Al-31%B4C复合材料的相对密度大于99.69%,抗拉强度大于300 MPa,断后延伸率大于3%,B4C颗粒均匀分布在基体中,并与基体紧密结合;Al-B4C复合材料板材的力学性能符合工程用中子吸收材料的要求。比较含不同质量分数B4C颗粒(10%、15%、20%、25%、30%、31%、35%、40%)的Al-B4C复合材料性能,当B4C质量分数为10%~40%时,随基体中B4C颗粒含量的增加,Al-B4C复合材料的密度和相对密度均逐渐降低;当B4C质量分数为10%~35%时,随基体中B4C颗粒含量的增加,Al-B4C复合材料的抗拉强度逐渐增大,断后延伸率逐渐降低。 相似文献
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L. R. Vishnyakov A. V. Maznaya L. N. Pereselentseva B. N. Sinaiskii 《Powder Metallurgy and Metal Ceramics》2006,45(5-6):239-243
The structure and physicomechanical properties of composite materials based on boron nitride within which new phases (mullite
and sialon) form during hot compaction are studied. It is established that the microstructure of composites is specified by
their texture formation caused by the crystal morphology of boron nitride particles and it is almost independent of composite
phase composition. It is shown that the main factor that affects strength is porosity. The dependence of strength on porosity
is exponential in character. The strength of boron nitride-mullite and boron nitride-sialon composites is 110–140 MPa and
at 20–1200°C it is almost unchanged.
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Translated from Poroshkovaya Metallurgiya, Nos. 5–6(449), pp. 33–39, May–June, 2006. 相似文献
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为了改善六方氮化硼(hBN)固体润滑剂和Ni-Cr合金基体之间的润湿性,采用硝酸镍分解-氢还原法制备Ni包覆hBN粉末(即Ni/hBN粉末).分别用Ni/hBN粉末和未包覆的hBN粉末作为固体润滑剂制备(Ni-Cr)/hBN自润滑复合材料,研究hBN粉末表面包覆Ni对该复合材料组织和性能的影响.结果表明:与hBN相比,... 相似文献
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机械球磨与烧结W基材料的组织与性能 总被引:1,自引:0,他引:1
采用机械球磨与热压工艺制备了W-TiC、W-Ni、W-CNTs(碳纳米管)和W-Ni-CNTs 4种W基材料。研究结果表明,机械球磨能显著降低复合粉的晶粒尺寸和增加晶格畸变。经机械球磨后热压的样品中W-TiC的致密度最好,密度达到18.36g/cm3;W-Ni和W-CNTs的密度分别为17.97g/cm3和18.23g/cm3,具有较好的致密性;W-Ni-CNTs样品密度为15.84g/cm3,致密度略低。微观组织分析表明:添加TiC粒子可以显著改善材料的烧结行为,但晶粒较大;添加少量Ni制备的样品,不仅致密度高,而且晶粒较小;添加CNTs可以改善W的烧结行为,同时能够抑制晶粒长大和对W晶界起到强化作用;同时添加Ni和CNTs样品的致密度较低,需要对Ni和CNTs的添加量及烧结工艺条件进一步优化。结合微观组织分析与显微硬度测试结果,发现W烧结体的显微硬度不仅和材料密度有关,而且和W晶粒大小及掺杂相有关。 相似文献
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Hosam ElRakayby 《粉末冶金学》2017,60(4):293-300
Hot isostatic pressing of nickel-based superalloys has important applications for manufacturing near-net shape parts such as turbine disks and jet engine parts, which have to operate at high temperatures. Finite element modelling can be used to predict deformation and densification behaviour of such superalloys. Thus, the cost and time of trial and error to obtain the required geometry of the part can be reduced, such that near-net shape parts can be manufactured more economically. Numerical simulations were carried out by implementing the model of ElRakayby and Kim into Abaqus-FEA. The model parameters (relative density functions f and c) for the nickel-based superalloy were obtained from the creep response and compressive strength of porous and solid powder compacts at high a temperature. The agreement between finite element calculations and the experimental data was good for densification, shape change and density distribution of nickel-based superalloy during hot isostatic pressing. 相似文献
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O. N. Grigor’ev T. V. Dubovik N. D. Bega V. A. Kotenko V. M. Panashenko V. I. Lyashenko A. A. Rogozinskaya L. I. Chernenko 《Powder Metallurgy and Metal Ceramics》2007,46(1-2):46-50
The formation of BN-B4C composite materials by sintering in nitrogen is investigated. Structural, mechanical, and chemical characteristics of these
materials are examined. Excellent dielectric properties, thermal and chemical stability, and erosion resistance in high-intensity
laser beams enable high-temperature application of BN-B4C composite materials.
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Translated from Poroshkovaya Metallurgiya, Vol. 46, No. 1–2(453), pp. 58–63, 2007. 相似文献
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V. G. Kayuk M. S. Koval’chenko I. S. Martsenyuk O. N. Grigor’ev 《Powder Metallurgy and Metal Ceramics》2007,46(5-6):228-235
The paper studies the densification kinetics in hot pressing of mixtures with equimass content (50 ∶ 50) of Cr3C2 and TiN without a binder at 1350, 1470, and 1800°C under 16.2, 21.6, and 35.7 MPa, a mixture of Cr3C2-50 wt.% TiN with 5 wt.% of the Ni-Cr binder at 1300, 1350, and 1370°C under 5 and 10 MPa, and a mixture of Cr3C2-50 wt.% TiN with 20 wt.% of the Ni-Cr binder at 1180, 1220, and 1270 °C under 5 and 10 MPa with isothermal holding for up
to 25 min. The behavior of materials in hot pressing is analyzed using the viscous flow theory for porous body. It is shown
that the compaction of an alloy without a binder and with the Ni-Cr binder in hot pressing is described by a generalized equation
of volume viscous flow of a porous body. It is controlled by non-linear creep with an effective activation energy of 3.2 eV
in materials without a binder and by a viscous flow in alloys with a metal binder. The structure and mechanical properties
of the materials obtained are studied.
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Translated from Poroshkovaya Metallurgiya, Vol. 46, No. 5–6 (455), pp. 29–37, 2007. 相似文献
19.
采用热等静压(HIP)技术成形复杂结构的2A12铝合金粉末零件,基于MSC.MARC软件的Shima模型,使用2A12铝合金材料参数实现成形过程的数值模拟。模拟结果表明,特征结构狭缝处粉末体的相对密度呈现梯度分布,侧面的粉末体相对密度分布均匀;石墨模具基本没有变形。实验结果表明,石墨和铝粉末发生了界面反应,型腔内壁存在凹坑和凸起缺陷;粉末试样的规定塑性延伸强度和抗拉强度分别为179 MPa和316 MPa;断口形貌显示试样断裂起源于粉末界面连接处,由金相显微照片分析材料已经完全致密。 相似文献
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热等静压近净成形工艺具有材料利用率高、坯料组织均匀性好的突出优势,是镍基粉末高温合金、粉末钛合金等复杂形状部件的重要成形工艺。介绍了热等静压近净成形的工艺特点和生产流程、热等静压近净成形技术在国内外的发展和应用以及粉末热等静压致密化的微观模型和宏观模型,通过对比分析不同模型的热等静压数值模拟和试验验证结果,总结了不同模型的优缺点,分析了影响数值模拟准确性的因素。 相似文献