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添加钴对W-Ni-Fe高密度合金性能的影响 总被引:4,自引:1,他引:3
在原料粉末中加入微量的Co元素,用粉末冶金液相烧结法制备了W-Ni-Fe高密度合金;采用金相显微镜、SEM等仪器对合金组织和杂质分布进行了分析。研究结果表明:添加钴元素后,增强了基体相对钨颗粒的润湿性,使钨颗粒表面更加圆滑,更加有利于塑性变形;提高了合金的钨颗粒与基体相之间的界面结合强度,从而提高了合金的强度和延伸率。 相似文献
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高密度钨合金具有良好的综合力学性能,是军民两用合金材料。由于钨熔点很高,一般只能通过液相烧结才能制备接近全致密的合金。为满足科技发展对高性能钨合金的需求,采用新方法、新工艺,设法降低液相烧结温度和缩短保温时间,制备具有高强度、高韧性的细晶、超细晶或纳米晶钨合金材料是发展趋势。采用新的烧结技术,如:固相烧结、两步烧结、微波烧结、放电等离子烧结等制备高密度钨合金成为近年该领域的研究热点,对这些新工艺的最新研究进展情况进行了介绍。 相似文献
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专利名称:一种超细钨-铜复合粉的制备方法专利申请号:02114601.2公开号:1392012申请人:西北工业大学文摘:提供了一种超细钨—铜复合粉体的制备方法。为改进钨—铜复合粉体的均匀性和材料的综合性能,解决符合粉体烧结成型过程中铜成分的稳定性问题,该发明采用液相化学沉积法,利用液相化学沉积铜溶液在反应器内进行动态生产,并在液相化学沉积铜溶液中加入了分散剂,消除了固体颗粒间的静电引力,使铜相均匀地沉积到超细钨粒子表面,得到由铜相基本包覆着钨相的单分散颗粒所组成的超细钨—铜复合粉体。用该发明制备的超细钨—铜复合粉体具有能耗小… 相似文献
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《中国钨业》2022,(1):49-54
多孔钨材料的孔隙特性和基体材料的机加工性能会影响发射极使用性能和寿命,本研究采用经过分级后的钨粉成功制备了超细多孔钨材料。利用扫描电镜、金相显微镜和超声波无损探伤设备表征了材料的微观组织特性,使用压汞法分析了超细多孔钨材料的孔隙特性,开发了薄片状超细多孔钨试件的去铜工艺。研究表明:分级技术可有效实现对钨粉特性的调控,包括费氏粒度、粒度分布和钨粉微观形貌;使用分级钨粉制备的多孔钨材料空隙特性良好,孔径分布为单峰分布,平均孔径为0.9μm,通孔率为17.1%,闭孔率为1.4%;真空高温物理去铜制备薄片状的多孔钨试件时,使用中部镂空的工装,可以保证试件在去铜完全的同时不发生变形。 相似文献
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硬质合金中WC晶粒内部微孔形成原因探讨 总被引:1,自引:0,他引:1
利用扫描电镜对以蓝钨与黄钨为原料制得的粗颗粒W粉、WC粉进行形貌观察,并与其对应的WC-Co硬质合金金相组织进行了对比。以此为基础对硬质合金中WC晶粒内部微孔这一比较常见的现象作出解释,即合金中WC晶粒内部微孔主要来源于原料W粉。实验结果表明,选用蓝钨为硬质合金生产原料可使合金中WC晶粒内部微孔明显减少,从而使合金的综合性能得到提高。 相似文献
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概述近年微波及超声波在钨冶金生产工艺中的应用研究进展,简介其应用工艺和技术.主要从微波在钨冶金中应用:促进黑、白钨矿浸出;促进含钨化合物合成;烧结含钨化合物与热分解制备三氧化钨;超声波在钨冶金中应用:强化钨矿浸出及仲钨酸铵结晶;辅助制备含钨化合物;工业探伤应用等领域进行介绍.微波及超声波技术在钨冶金中应用将越来越广泛和深入. 相似文献
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高密度钨合金研究的新进展 总被引:2,自引:1,他引:1
从原材料、烧结工艺及其后处理、强韧化和杂质对高密度钨合金的影响等方面介绍了国内外近10年来在高密度钨合金领域所取得的进展,并从这些方面详细讨论了影响高密度钨合金性能的具体因素。此外,提出了钨合金今后的发展方向。 相似文献
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Dynamic deformation behavior of an oxide-dispersed tungsten heavy alloy fabricated by mechanical alloying 总被引:14,自引:0,他引:14
Sanghyun Park Dong-Kuk Kim Sunghak Lee Dong-Kuk Kim Ho Jin Ryu Soon Hyung Hong Ho Jin Ryu 《Metallurgical and Materials Transactions A》2001,32(8):2011-2020
The objective of this study is to investigate the dynamic deformation and fracture behavior of an oxide-dispersed (OD) tungsten
heavy alloy fabricated by mechanical alloying (MA). The tungsten alloy was processed by adding 0.1 wt pct Y2O3 powders during MA, in order to form fine oxides at triple junctions of tungsten particles or at tungsten/matrix interfaces.
Dynamic torsion tests were conducted for this alloy, and the test data were compared with those of a conventional liquid-phase
sintered (LPS) specimen. A refinement in tungsten particle size could be obtained after MA and multistep heat treatment without
an increase in the interfacial area fraction between tungsten particles. The dynamic test results indicated that interfacial
debonding between tungsten particles occurred over broad deformed areas in this alloy, suggesting the possibility of adiabatic
shear-band formation. Also, oxide dispersion was effective in promoting interfacial debonding, since the fine oxides acted
as initiation sites for interfacial debonding. These findings suggest that the idea of forming fine oxides would be useful
for improving self-sharpening and penetration performance in tungsten heavy alloys. 相似文献
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Effect of tungsten particle shape on dynamic deformation and fracture behavior of tungsten heavy alloys 总被引:1,自引:0,他引:1
Dong-Kuk Kim Sunghak Lee Heungsub Song 《Metallurgical and Materials Transactions A》1998,29(3):1057-1069
The effect of the tungsten particle shape on the dynamic deformation and fracture behavior of tungsten heavy alloys was investigated.
Dynamic torsional tests were conducted using a torsional Kolsky bar for five alloys, one of which was fabricated by the double-cycled
sintering process, and then the test data were compared via microstructures, mechanical properties, adiabatic shear banding, and fracture mode. The dynamic torsional test results indicated
that in the double-sintered tungsten alloy whose tungsten particles were very coarse and irregularly shaped, cleavage fracture
occurred in the central area of the gage section with little shear deformation, whereas shear deformation was concentrated
in the central area of the gage section in the other alloys. The deformation and fracture behavior of the double-sintered
alloy correlated well with the observation of the impacted penetrator specimen and the in situ fracture test results, i.e., microcrack initiation at coarse tungsten particles and cleavage crack propagation through tungsten particles. These findings
suggested that the cleavage fracture mode would be beneficial for the self-sharpening effect, and, thus, the improvement of
the penetration performance of the double-sintered tungsten heavy alloy would be expected. 相似文献
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Dong-Kuk Kim Sunghak Lee Heung-Sub Song 《Metallurgical and Materials Transactions A》1998,29(13):1057-1069
The effect of the tungsten particle shape on the dynamic deformation and fracture behavior of tungsten heavy alloys was investigated.
Dynamic torsional tests were conducted using a torsional Kolsky bar for five alloys, one of which was fabricated by the double-cycled
sintering process, and then the test data were compared via microstructures, mechanical properties, adiabatic shear banding, and fracture mode. The dynamic torsional test results indicated
that in the double-sintered tungsten alloy whose tungsten particles were very coarse and irregularly shaped, cleavage fracture
occurred in the central area of the gage section with little shear deformation, whereas shear deformation was concentrated
in the central area of the gage section in the other alloys. The deformation and fracture behavior of the double-sintered
alloy correlated well with the observation of the impacted penetrator specimen and the in situ fracture test results, i.e., microcrack initiation at coarse tungsten particles and cleavage crack propagation through tungsten particles. These findings
suggested that the cleavage fracture mode would be beneficial for the self-sharpening effect, and, thus, the improvement of
the penetration performance of the double-sintered tungsten heavy alloy would be expected. 相似文献
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以Co、Ni作黏结剂,选择不同Co/Ni比,用粉末冶金法制备出HRC硬度在3043之间的93W-Co-Ni钨合金。采用光学金相、扫描电镜对合金组织形貌进行表征,采用准静态拉伸试验对合金的抗拉强度及延伸率进行测试,采用洛氏硬度计对合金硬度进行测定。结果表明:随着Co/Ni比增加,合金的烧结温度逐渐增加,其抗拉强度与延伸率急剧降低,而硬度先增加之后趋于稳定;当Co/Ni≥1.0时,合金抗拉强度很低,延伸率≤1%;当Co/Ni≥4时,其HRC硬度值稳定在4143之间的93W-Co-Ni钨合金。采用光学金相、扫描电镜对合金组织形貌进行表征,采用准静态拉伸试验对合金的抗拉强度及延伸率进行测试,采用洛氏硬度计对合金硬度进行测定。结果表明:随着Co/Ni比增加,合金的烧结温度逐渐增加,其抗拉强度与延伸率急剧降低,而硬度先增加之后趋于稳定;当Co/Ni≥1.0时,合金抗拉强度很低,延伸率≤1%;当Co/Ni≥4时,其HRC硬度值稳定在4143之间,明显高于一般的W-Ni-Fe合金,这主要与Co对W基体的润湿性较差及两者之间易形成脆性化合物Co7W6有关。 相似文献
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Dong-Kuk Kim Sunghak Lee Ho Jin Ryu Soon Hyunghong Joon-Woong Noh 《Metallurgical and Materials Transactions A》2000,31(10):2475-2489
In this study, tungsten heavy alloy specimens were fabricated by mechanical alloying (MA), and their dynamic torsional properties
and penetration performance were investigated. Dynamic torsional tests were conducted on the specimens fabricated with different
sintering temperatures after MA, and then the test data were compared with those of a conventionally processed specimen. Refinement
of tungsten particles was obtained after MA, but contiguity was seriously increased, thereby leading to low ductility and
impact energy. Specimens in which both particle size and contiguity were simultaneously reduced by MA and two-step sintering
and those having higher matrix fraction by partial MA were successfully fabricated. The dynamic test results indicated that
the formation of adiabatic shear bands was expected because of the plastic localization at the central area of the gage section.
Upon highspeed impact testing of these specimens, self-sharpening was promoted by the adiabatic shear band formation, but
their penetration performance did not improve since much of kinetic energy of the penetrators was consumed for the microcrack
formation due to interfacial debonding and cleavage fracture of tungsten particles. In order to improve penetration performance
as well as to achieve selfsharpening by applying MA, conditions of MA and sintering process should be established so that
alloy densification, particle refinement, and contiguity reduction can be simultaneously achieved. 相似文献
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将93W-4.9Ni-2.1Fe混合粉末压坯经过脱脂预烧、渗钼和脱钼处理以及烧结,得到W(Mo)-Ni-Fe高密度合金,采用金相分析、能谱分析、显微硬度测试等方法对该合金的成分和微观结构进行分析.结果表明,W-Ni-Fe高密度合金经渗钥处理后形成显微组织、钼含量和镍铁粘结相的梯度分布,其特征是合金表层的粘结相少于芯部:... 相似文献