共查询到18条相似文献,搜索用时 78 毫秒
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为了提升高速钢的红硬性及韧性,通过粉末球磨(碳化物及金属粉末)加真空烧结工艺制备了不同含量的NbC颗粒增强ASP2080高速钢复合材料。利用XRD、SEM、EDS、万能拉伸试验机等对NbC/ASP2080高速钢复合材料的微观组织及力学性能进行了表征分析。结果表明:NbC的添加不会改变复合材料的相结构,并且随着NbC含量的增加,热处理态复合材料的基体晶粒尺寸明显减小;热处理能显著提升复合材料的硬度、抗弯强度及冲击韧性;热处理态复合材料的硬度、抗弯强度及冲击韧性随着NbC含量的增加均出现先增大后减小的趋势。NbC含量为4%时的热处理态复合材料拥有最佳的综合性能,其平均晶粒尺寸为6.52μm,硬度、抗弯强度和冲击韧性分别为71.7 HRC、825.3 MPa、6.75 J/cm2。 相似文献
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采用放电等离子烧结法制备了碳纤维增强铜基复合材料CFs/Cu。利用光学显微镜、扫描电镜和万能试验机检测并分析了不同碳纤维长度对复合材料相对密度、显微结构及力学性能的影响。结果表明, 添加质量分数为2.5%不同长度的碳纤维有利于提高CFs/Cu复合材料力学性能; 但随着碳纤维长度增加, CFs/Cu复合材料相对密度下降, 对力学性能的增强效果降低。添加1 mm长度碳纤维的复合材料相对密度和抗弯强度最佳, 分别为99.34%和805.47 MPa, 相较于未添加纤维的材料, 其强度提升了65%; 断口形貌显示为河流状花样和解理台阶特征, 存在较少韧窝, 属于以脆断为主, 伴随少量韧性断裂的混合断裂机制。 相似文献
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采用湿法球磨的方式将质量分数0.10%的多壁碳纳米管(MWCNTs)分散在铜粉中, 干燥后经放电等离子烧结, 获得了CNTs/Cu复合材料的预制体, 采用冷轧方式将预制体轧制为薄片。研究了CNTs/Cu复合材料的物理性能及微观结构随轧制过程的变化规律。结果表明, CNTs/Cu复合材料的硬度、密度随着轧制的进行不断升高, 晶粒被细化。断口形貌为大量韧窝, 属于韧性断裂, 并在断口处发现团聚的CNTs。轧制总压下量为90%时, 薄带的电阻率为0.020 0 μΩ·m, 抗拉强度为410.24 MPa。 相似文献
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铜基复合材料以其优异的电学、耐磨和力学等性能受到了许多学者的重视。近年来,陶瓷颗粒、碳纳米相等因其结构特性和物理性能、力学性能的优异性,已成为铜基复合材料常用的增强相之一。概述了不同增强相(Al2O3、CNTs、MAX)增强铜基复合材料的制备方法和综合性能方面的研究进展;阐述了增强相在铜基体中的分散性以及增强相与基体之间的界面结合对铜基复合材料综合性能的影响及强化机制,旨在阐明通过增强相的结构设计实现综合性能良好的铜基复合材料的设计思路。 相似文献
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采用旋转化学气相沉积法和真空热压烧结工艺原位制备了综合性能优良的石墨烯-铜基复合材料。利用拉曼光谱仪、扫描电子显微镜和光学显微镜等仪器, 并通过测试材料维氏硬度、导电性和导热性, 分析了复合粉体的结构和形貌以及石墨烯添加对复合材料组织和性能的影响。结果表明, 在旋转化学气相沉积过程中, 通过改变甲烷气体的浓度(由0.17%提高到0.67%), 结合真空热压烧结工艺, 成功制备出石墨烯含量为0.015%和0.026%的铜基复合材料。2种复合材料均接近完全致密(≥99.0%); 铜基体晶粒尺寸由于石墨烯的添加而明显细化:纯铜块体材料的平均晶粒直径约为46.8 μm, 而石墨烯含量为0.015%和0.026%的复合材料的平均晶粒直径分别为22.7和17.9 μm; 复合材料的硬度显著提高, 相比纯铜样品均增长了约30%; 随着石墨烯含量增加, 复合材料导电性和导热性逐渐降低, 但下降幅度较小, 与纯铜样品接近。 相似文献
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采用碳纤维无纬布/网胎毡针刺整体毡作为预制体,经过化学气相渗透和真空无压熔渗法制备出了碳纤维增强铜基复合材料。采用偏光显微镜和扫描电镜观察了材料的微观组织形貌,并探讨了增强体结构对复合材料的物理性能和力学性能的影响。研究结果表明,通过在1 220 ℃下真空熔渗0.5 h后,含钛锡青铜可以渗入碳纤维多孔预制体中,从而制备出致密的碳纤维增强铜基复合材料;相比于布毡比1∶1的复合材料,布毡比3∶1的复合材料硬度提升了17%,在垂直无纬布方向和平行无纬布方向的压缩强度分别提升了37%和44%,抗弯强度提升了47%。 相似文献
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Carbonation takes place in the fiber-cement composites through the diffusion of carbon dioxide (CO2) through the unsaturated pores of the cement matrix, and through its reaction with the hydration products of the Portland cement (mainly calcium hydroxide and CSH phases). The use of this technology in the fiber-cement production consists of an interesting procedure to prematurely decrease the alkalinity of the cement matrix, which is potentially harmful to the cellulose fiber reinforcement. It is also an initiative to CO2 sequestration and partial replacement of petroleum-based fibers. Therefore, the objective of the present work is to show the impact of accelerated carbonation on the microstructure and physical properties of fiber-cement composites reinforced with cellulose pulp and synthetic fibers. The effectiveness of the accelerated carbonation was confirmed by thermogravimetric (TG) analysis. Accelerated carbonation increased bulk density (BD) and decreased apparent porosity (AP). The SEM micrographs show that the calcium carbonate (CaCO3) formed from the carbonation reaction is precipitated in the pore structure of the matrix. The interface between the cellulose fibers and the cement matrix in the carbonated composites was improved, decreasing the typical voids around the cellulose fibers that prejudice the fiber-cement performance at long term. 相似文献
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通过粉末冶金真空烧结法,利用NbC粉末与气雾化ASP2030高速钢制备了NbC_(p)/ASP2030高速钢复合材料。采用SEM、XRD、EDS等检测手段,研究了不同NbC添加量对ASP2030高速钢的显微组织、物相组成及力学性能的影响。结果表明,当真空烧结温度达到1220℃,所制得的复合材料主要相有Martensite、M_(7)C_(3)碳化物、M_(6)C碳化物、MC碳化物以及γ-Fe;当NbC加入量逐渐增加,烧结态复合材料的抗弯强度与冲击韧性都出现一定程度下降,而硬度则逐渐上升。在NbC含量达到2%时,复合材料的冲击韧性为5.34J/cm^(2),抗弯强度为1918.3MPa,硬度为53.9HRC。 相似文献
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NING Yuan-tao ZHANG Xiao-hui ZHANG Jie 《材料研究与应用》2005,(3):521-529
The influences of the thermomechanical processing, including the solidification conditions, the cold deformation and the intermediate annealing treatment, on the structure and properties of the Cu-10Ag alloy in situ composite were studied in this paper. The cast structure and the structural changes in the cold deformation and intermediate annealing process were observed. The properties including the ultimate tensile strength (UTS) and the electrical conductivity were determined. A two-stage strain strengthening effect for the Cu-10Ag alloy in situ filamentary composite was observed. The factors influencing the UTS and conductivity were discussed. The solidification conditions in the range of 10-1000 K/s cooling rates and the intermediate heat treatment showed obviously influence on the structure and properties on the Cu-10Ag alloy in situ filamentary composite. The typical properties of the Cu-Ag alloy in situ filamentary composites through thermomechanical processing were reported. 相似文献
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Influence of thermomechanical processing on the structure and properties of Cu-Ag alloy in situ composites 总被引:3,自引:0,他引:3
1IntroductionTheinsitucomposites based on copper alloys with high strength and high electrical conductivity hasbeen developed for applications such as high field magnets,where the tensile strengths in excess of1GPaand electric conductivity above50%IACS(International Annealed Copper Standard)are required[1-5].TheCu alloys included essentially two types:one is the alloy system of Cu with face-centered-cubic(fcc)ele-ments such as Ag,another is the alloy systemof Cu with body-centered-cubic(b… 相似文献
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Influence of thermomechanical processing on the structure and properties of Cu-Ag alloy in situ composites 下载免费PDF全文
The influences of the thermomechanical processing, including the solidification conditions, the cold deformation and the intermediate annealing treatment, on the structure and properties of the Cu-10Ag alloy in situ composite were studied in this paper. The cast structure and the structural changes in the cold deformation and intermediate annealing process were observed. The properties including the ultimate tensile strength (UTS) and the electrical conductivity were determined. A two-stage strain strengthening effect for the Cu-10Ag alloy in situ filamentary composite was observed. The factors influencing the UTS and conductivity were discussed. The solidification conditions in the range of 10-1000 K/s cooling rates and the intermediate heat treatment showed obviously influence on the structure and properties on the Cu-10Ag alloy in situ filamentary composite. The typical properties of the Cu-Ag alloy in situ filamentary composites through thermomechanical processing were reported. 相似文献
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