共查询到19条相似文献,搜索用时 250 毫秒
1.
将金属Al、Al3Ti和TiC以AlTiC中间合金的形式以及ZrO2颗粒共同引入Al2O3基体材料中,热压制备了Al2O3/TiC/ZrO2/AlN复合材料.在此基础上,添加(体积分数)1%透辉石作为烧结助剂,以实现复合材料的液相烧结并促进其致密化程度.复合材料在烧结过程中有新相AlN生成;同时Al、TiC以及Al3Ti释放的Ti原子发生原子重组生成Al2Ti4C.对热压后材料的硬度、断裂韧度和抗弯强度进行了测试和分析;探讨了透辉石对材料致密化程度及力学性能的影响效果;研究了复合材料断面断裂方式的变化对其力学性能的影响;并对AlTiC中间合金的细化特性进行了分析. 相似文献
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《钢铁钒钛》2020,(1)
以Ti粉、Fe粉和B_4C粉末为原料,采用冷等静压+高真空烧结方法制备了不同(TiB+TiC)增强相体积分数的Ti-Fe合金基复合材料(Fe元素质量分数为5%~15%),重点讨论了Fe含量和增强相对复合材料微观组织和力学性能的影响规律。结果表明,在1 150~1 250℃烧结温度下制备出Ti-Fe合金基复合材料致密度随Fe含量与增强相体积分数升高而降低。Fe含量增加使基体中α相层片状结构细化,而B_4C粉末的添加生成原位自生TiC颗粒和TiB纤维增强相,基体结构由层片状转变为等轴状。材料力学性能随Fe含量和增强相体积分数增加而提高。在1 150℃烧结制备的Ti-15%Fe-10vol%(TiB+TiC)复合材料硬度(HV)达到334,抗压强度达到2 040 MPa。 相似文献
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为提高钢基硬质涂层的表面质量和显微硬度,采用真空消失模铸造法引发自蔓延高温合成(SHS)反应,在铸件表面制备原位合成TiC颗粒增强钢基硬质涂层。通过X-ray、OM、SEM、EDS及显微硬度测试等方法,研究了稀释剂TiC的加入量对钢基硬质涂层微观组织和力学性能的影响。结果表明:硬质涂层与基材之间呈冶金结合,涂层组织由TiC颗粒和α-Fe基体相构成;随外加TiC含量的增加,可降低燃烧反应温度,提高涂层组织致密度,原位合成的TiC颗粒细小呈圆球或近圆球形状,均匀分布在基体组织中,显著提高了TiC颗粒总体积分数和硬质涂层显微硬度,其中TiC加入量为10%(质量分数)时,涂层的综合性能最佳。 相似文献
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《稀有金属》2019,(7)
采用X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)等现代检测分析方法,研究了由TiH_2-石油焦-铝铈合金与铝液制备的不同Ce含量的Al-Ti-C-Ce母合金的显微组织,结果表明:Al-Ti-C-Ce母合金由α(Al),(TiC),(TiAl_3),(Ti_2Al_(20)Ce)相组成; Al-Ti-C-Ce母合金铸样晶界为连续的共晶组织,晶内分布着大量的粗大第二相组织,晶界共晶和晶内第二相中均含有Ti_2Al_(20)Ce相。部分大颗粒第二相组织为复合结构,复合晶粒内部存在颜色较深的α(Al)+Ti_2Al_(20)Ce+(TiC)的包晶组织。线分析结果表明:第二相粒子中,元素C的分布相对均匀,粒子内部C, Al含量相对较低, Ti, Ce含量相对较高, Ce的分布显著高于粒子外部区域;具有复合结构的第二相中所包含的粒子区域, Ti, C含量极高,而Al, Ce含量较低。合金在凝固过程中, TiC粒子作为晶核优先析出, TiAl_3相通过TiC粒子形核,并与游离的Ti, Ce发生包晶反应生成Ti_2Al_(20)Ce相,多余Ce原子会与晶界处的TiC, TiAl_3的复合粒子反应生成TiC, Ti_2Al_(20)Ce复合粒子。含Ti, C, Ce的复合粒子作为领先相优先析出,细化Al-Ti-C-Ce母合金晶粒。 相似文献
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对原位生成TiC颗粒增强钛基复合材料进行锻造,通过金相显微镜(OPM)、扫描电镜(SEM)和能谱分析(EDS)等手段,研究锻造后材料的显微组织及拉伸断口形貌,利用CETR UMT-3多功能微摩擦磨损测试仪测定材料的摩擦磨损行为。结果表明:锻造后钛基复合材料的组织缺陷得到消除,晶粒明显细化,抗拉强度由1 126 MPa提高到1 309 MPa;材料拉伸断口为TiC解理断裂与基体局部延性断裂相结合的混合型断口。随载荷不断增加,TiC粒子首先断裂,裂纹在基体中迅速扩展,导致复合材料失效。在摩擦实验初期,材料的摩擦因数较小且较稳定,而后期摩擦因数变化幅度较大;随时间延长,磨损面上的TiC颗粒发生破碎,失去承载作用,导致磨损量变大;摩擦磨损过程中材料表面Ti发生氧化,形成氧化磨损;锻造后材料的磨损量及摩擦因数都减小。 相似文献
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本文以雾化铁粉、羰基镍粉、钼粉、电解铜粉、钛粉及石墨粉为实验原料,在Fe-2%Ni-0.5%Mo-2%Cu-0.3%C基础上,按Ti和C原子比1∶1同时添加Ti和石墨(Ti的添加量为质量分数0~4%),利用粉末冶金与原位烧结合成技术制备了TiC颗粒增强铁基粉末冶金烧结材料,并用光学显微镜(OM)和扫描电子显微镜(SEM)等手段研究了实验材料的显微组织及性能。研究结果表明:实验粉末冶金烧结材料的组织主要为珠光体、铁素体及贝氏体。随着Ti加入量的增加,珠光体含量增多,且珠光体片间距更细小,而铁素体及贝氏体组织逐渐减少。原位合成的TiC颗粒尺寸约在0.3μm,主要分布在珠光体晶粒边界处。随Ti加入量的增大,材料的表观硬度提高,而抗弯强度和密度下降。断口形貌没有表现出明显的塑性变形,属于脆性断裂。 相似文献
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利用Al、Ti、C粉末原料,采用铝熔体热爆法合成了相同成分不同微观组织形貌的两种Al-Ti-C中间合金晶粒细化剂。借助X射线衍射(XRD)、大型光学显微镜(MEF3)等分析手段研究了重熔保温时间对Al-Ti-C中间合金微观组织及细化效果的影响。结果表明:合成的两种Al-Ti-C中间合金均由Al、TiAl3和TiC组成。重熔时,保温时间对Al-Ti-C中间合金微观组织产生重要影响。随着重熔保温时间的延长,TiAl3会发生聚集、长大,而TiC颗粒有聚集倾向,但保温过程中,TiAl3和TiC相表现出较强的稳定性,并没有生成其他杂相如Al4C3等。重熔后的Al-Ti-C中间合金仍具有一定的晶粒细化能力。 相似文献
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通过超声振动在7075合金中添加SiO2,原位生成Al2O3颗粒,利用X射线衍射仪(XRD)、自带能谱分析仪(EDS)的扫描电子显微镜(SEM)、透射电镜(TEM)、浸泡腐蚀实验和电化学测试实验对合金的微观组织、物相组成和耐腐蚀性能进行分析。结果显示,超声振动和Al2O3颗粒的原位生成可以细化合金的微观组织,将团聚的Al2O3颗粒分散均匀,且Al2O3颗粒可作为异质形核的核心,提高形核率。超声态Al2O(3(p))/7075合金主要由Al、Al2O3、Al7Cu2Fe、Al2CuMg、Mg2Zn相组成。相比于7075合金,超声态Al2O(3(p))/7075合金的失重腐蚀速率... 相似文献
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Shivkumar Khaple V. V. Satya Prasad Brahma Raju Golla 《Transactions of the Indian Institute of Metals》2018,71(11):2713-2716
In this paper, the role of Ti on the in-situ formation of carbides and its effect on the microstructure of Fe-7Al-0.35C alloy have been investigated. Initially, Thermo-Calc software was used to predict the phases present in the alloys which were validated by experimental work. Vacuum arc remelting process was used to make an alloy pancake of 10-mm thickness, which was hot-rolled to 2-mm thickness. The alloys were characterised by X-ray diffraction, optical, scanning electron microscope and electron probe micro-analysis. The results show that all the alloys exhibit two types of TiC precipitates, which are dark cuboidal as primary and dark acicular type as secondary precipitates along with grey-coloured needle-shaped κ-carbide precipitate in α(Fe–Al) matrix. The carbon present in the alloy is partitioned between TiC and κ-carbide precipitates. Addition of Ti has also resulted in grain refinement of all the alloys. 相似文献
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以羰基Fe粉、Ti粉及C粉为原料,采用真空原位反应烧结法制备颗粒增强型Fe(TiC)_p复合材料。对微观组织的观察和元素分析发现,原料Ti粉对TiC增强颗粒的形貌和粒径具有较明显的遗传性。对这一组织遗传性,从反应热力学和扩散动力学方面给出解释,并基于此认识,设计原料Ti粉的球磨细化预处理工序。经预处理后原位反应烧结材料的致密度明显提升,并能够在铁基体中形成分散度更高、尺度更细小、且近球形的TiC增强颗粒,从而使复合材料的硬度从HV99.4提高到HV152.3,抗弯强度从550 MPa提高到935 MPa。 相似文献
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采用Ti粉末分别与碳化物Mo2C和VC粉末混合,通过冷等静压、真空高温烧结原位生成6种不同成分的TiC颗粒增强钦基复合材料,用UMT-3型摩擦试验机研究合金元素Mo和V以及Mo2C、VC添加量对钛基复合材料干磨擦性能的影响.测定不同样品的洛氏硬度和基体的显微硬度,用金相显微镜(OM)、X射线衍射仪(XRD)观察和分析样... 相似文献
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Synthesis and Characterization of Ti/(TiB + TiC) Hybrid in-situ Composites by Spark Plasma Sintering
Since Ti alloys exhibit inferior wear resistance and suffer considerable loss in mechanical strength at high temperature, it is aimed at synthesis an in-situ Ti/(TiB + TiC) hybrid composite. In order to synthesis Ti/(TiB + TiC) in-situ composite, B4C particulate was mixed with titanium powder and sintered at 1400 °C at different time intervals by spark plasma sintering. Sintering parameters were optimized according to the complete in-situ reactions. Density of the sintered compacts was measured by Archimedes principle. Energy dispersive spectroscope and optical microscope observations of the sintered samples revealed that with increasing sintering time TiB and TiC particulates were gradually transforming into needle like structure and near equiaxed structure, respectively. 相似文献
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Al-Ti-C master alloy was prepared by SHS (Self-propagating High temperature Synthesis)-melting technique. Effect of yttrium addition level on the microstructures of the master alloy was studied by XRD, SEM and EDS. The experimental results show that the addition of 1.0%Y is beneficial to the formation of TiC particles; Al-Ti-C-1.0Y consists of rod-like and blocky TiAl3, TiC, Al3Y and α-Al matrix. Y is found around TiC particles in Al-Ti-C-0.5Y master alloy while blocky (AlTiY) phase appears in Al-Ti-C-1.0Y master alloy. Al3Y with dendritic morphology and small blocky Al2Y except for TiC are found in Al-Ti-C-2-0Y master alloy. 相似文献
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Mohammad Hassan Shirani Bidabadi Ali Saidi Masoud Kasiri Mohammad Ahmadi Renani Akbar Chami 《Metallurgical and Materials Transactions A》2013,44(10):4800-4808
In the current study, Ni50Fe50 alloy powders were prepared using a high-energy planetary ball mill. The effects of TiC addition (0, 5, 10, 20, and 30 wt pct) and milling time on the sequence of alloy formation, the microstructure, and microhardness of the product were studied. The structure of solid solution phase, the lattice parameter, lattice strain, and grain size were identified by X-ray diffraction analysis. The correlation between the apparent densities and the milling time is explained by the morphologic evolution of the powder particles occurring during the high-energy milling process. The powder morphology was examined using scanning electron microscopy. It was found that FCC γ (Fe–Ni) solid solution was formed after 10 hours of milling, and this time was reduced to 7 hours when TiC was added. Therefore, brittle particles (TiC) accelerate the milling process by increasing crystal defects leading to a shorter diffusion path. Observations of polished cross section showed uniform distribution of the reinforcement particles. The apparent density increases with the increasing TiC content. It was also found that the higher TiC amount leads to larger lattice parameter, higher internal strain, and lower grain size of the alloy. 相似文献
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激光烧结法制备原位增强型多孔镍基复合材料 总被引:1,自引:0,他引:1
对自熔性镍基合金和TiH_2的混合粉末进行了激光烧结实验,并采用XRD、SEM、EDX等分析手段对烧结试样的微观组织结构进行了表征,对试样中的孔结构及析出相的成形机制进行了初步探讨.结果表明,烧结后试样中存在原位增强相TiC、TiB_2和孔结构;大量微米级尺寸的圆孔以及呈放射状或针叶状的高温强化相CrB均匀分布于基体中. 相似文献
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A particulate Al-30 wt pct TiC composite was employed as a grain refiner for the Al-4.5 wt pct Cu alloy. The composite contains
submicron TiC particles. The addition of the TiC grain refiner to the metal alloy in the amount of 0.1 Ti wt pct effected
a remarkable reduction in the average grain size in Al-4.5 wt pct Cu alloy castings. With the content of over 0.2 Ti wt pct,
the grain refiner maintained its refining effectiveness even after a 3600-second holding time at 973 K. The TiC particles
in the resulting castings were free of interfacial phases. It is concluded that the TiC are the nucleating agents and that
they are resistant to the “fading effect” encountered with most grain refiners. 相似文献