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采用Ti、Si、C单质粉末为原料,添加少量Al元素粉末为助剂,通过机械合金化和热处理制备高纯Ti3SiC2材料。采用XRD和SEM研究该材料的物相组成和显微结构。研究结果表明,机械合金化Ti、Si、C单质混合粉末,会诱发自蔓延反应,生成组成相为TiC、Ti3SiC2、TiSi2和Ti5Si3的粉末与颗粒产物。添加适量的Al元素可消除硅化物,明显促进Ti3SiC2的反应合成。采用Ti、Si、C、Al单质粉末进行机械合金化,可制备出主相为TiC与Ti3SiC2的粉末与颗粒产物。对掺Al机械合金化粉末产物压制后,在900~1 100℃热处理2 h,可制备出纯度大于95%(质量分数)的Ti3SiC2材料,而颗粒产物在900~1 200℃进行热处理,亦可获得纯度为96%的Ti3SiC2材料。但在1 300℃,热处理产物中的Ti3SiC2会发生严重分解,部分分解为TiC和少量硅化物,使产物纯度降低。 相似文献
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以钛铁粉、铬铁粉、铁粉、胶体石墨和镍粉等为原料,原位合成了TiC/Cr18Ni8、TiC/Cr19Al3和TiC/Ni40钢结硬质合金,并用扫描电镜、X射线衍射仪和洛氏硬度计、拉力试验机等对不同粘结相所制备的试样进行了组织结构分析和物理力学性能检测.结果表明:钢结硬质合金主要相组成为TiC、Fe-Cr-Ni和Fe-Cr固溶体,TiC晶粒细小,形状较为规则;粘结相对原位反应合成的钢结硬质合金的密度、硬度和所合成的TiC晶粒有较大影响,在相同烧结条件下TiC/Ni40钢结硬质合金的密度和硬度比TiC/Cr18Ni8和TiC/Cr19Al3钢结硬质合金的高,但TiC/Ni40钢结硬质合金中所合成的TiC晶粒比TiC/Cr18Ni8和TiC/Cr19Al3钢结硬质合金中合成的TiC晶粒偏聚现象严重.TiC/Ni40钢结硬质合金的硬度为60~70.5HRC,TiC/Cr18Ni8和TiC/Cr19Al3钢结硬质合金的硬度多在20~50HRC之间.三者的抗弯强度为960~1452MPa. 相似文献
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采用热爆合成技术制备TiC/Ni3Al复合材料,通过DSC,XRD,SEM等分析手段对Ti-C-3Ni-Al体系热爆反应过程及复合材料进行了研究。结果表明:Ni,Al在反应生成Ni3Al的同时引发了Ti和C之间生成TiC的反应,形成了纯净的TiC/Ni3Al复合产物,Ti-C-3Ni-Al体系的反应温度与TiC含量无关。热爆产物的微观组织形貌跟体系成分及热爆温度有关,TiC含量愈高,TiC颗粒粒度愈大,热爆产物中微观孔隙愈少;TiC颗粒的粒度随热爆温度的升高而增大,形状从近球形发育成多边形。热爆产物的致密度随着TiC含量增加及热爆温度的升高均表现出先增加后减小的变化趋势。当TiC含量为35%左右,热爆温度为750℃左右时,产物致密度最高。不同成分复合材料的显微硬度不同,TiC含量增加,复合材料显微硬度显著提高。 相似文献
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采用3Ti/1.1Al/2C粉体为原料,通过机械合金化与热处理,制备高纯Ti3AlC2材料。采用XRD、SEM和EDS对试样的物相组成、微观形貌和微区成分进行分析与表征。结果表明,3Ti/1.1Al/2C粉体机械合金化9 h后,元素粉末间会发生化学反应,合成了TiC和Ti3AlC2的复合粉体材料。粉体材料的晶粒比较细小,颗粒直径约为0.5~2μm。同时产物中有一些坚硬、细小的块体出现,小块体中的TiC和Ti3AlC2晶粒发育良好,TiC晶粒大小约2μm,Ti3AlC2晶粒长约10μm、宽约2μm。对得到的机械合金化粉体进行热处理,经900℃保温2 h可获得组织细小(颗粒直径0.5~1μm)、高纯(96.6%)的Ti3AlC2材料。继续升温,会导致Ti3AlC2材料分解。温度升至1 300℃时,物相分析表明试样仅由TiC相组成,组织致密,TiC晶粒大小约5~10μm。 相似文献
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采用机械合金化法制备了纳米TiC增强Ti基复合粉末,通过XRD、SEM、TEM和EDS分别表征粉末的物相、形貌、晶体结构和元素分布,探索球磨转速、球料比及球磨时间对复合粉末物相形貌的影响。结果表明:当球磨转速达到300 r/min以上、球料比达到20∶1以上时,球磨效率无明显差异。球磨时间达到10 h,粉末中TiC物相明显;继续延长球磨时间至20 h,得到纳米级TiC增强相。在300 r/min球磨转速、20∶1球料比、20 h球磨时间条件下,可得到纳米TiC增强Ti基复合粉末,粉末中部分区域呈非晶态,大量纳米TiC颗粒弥散分布于粉末中。 相似文献
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机械合金化制备高纯NiAl粉末 总被引:1,自引:0,他引:1
采用机械合金化方法制备NiAl粉末,用XRD和SEM对合成样品进行物相组成和形貌分析,研究了球磨时间和转速对NiAl粉末合成的影响规律.结果表明:球料比6:1,转速500 r/min时,球磨5h后NiAl合成反应基本完成,但由于铝粉的损失,导致合成粉末物相不纯,有少量Ni3Al存在;转速影响机械合金化方法制备高纯NiAl粉,选择合适的转速(365 r/min)可以制得纯NiAl粉. 相似文献
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CUI Xianghong WANG Feng WANG Shuqi YANG Zirun GAO Mingjuan WEI Minxian 《钢铁研究学报(英文版)》2009,16(2):89-0
A heat resistant gradient composite was synthesized in situ on steel with the self propagating high temperature synthesis (SHS) reaction of 3Ni Al Ti C system during casting. The phases, microstructure, and composition of the composite were analyzed by using an X ray diffractometer (XRD), and a scanning electron microscope (SEM) coupled with an energy dispersive X ray spectroscope (EDS). The formation mechanism of the composite is also discussed. TiC/Ni3Al/steel gradient composite is achieved by forming the gradient distributions of Fe, Ni, and Al, accompanied with the gradient variation of the microstructure from TiC/Ni3Al, to TiC/Ni3Al/steel, and to steel. The composite is in situ synthesized through whole reaction of 3Ni Al Ti C system in liquid steel and densification procedure, and the liquid steel infiltrates into pores in the SHS product and forces liquid Ni3Al to form self compaction further. 相似文献
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采用前驱体碳化复合技术制备了Ti-Fe-C和Ti-Ni-C两种体系的反应热喷涂复合粉末,通过氧乙炔火焰喷涂原位合成并沉积了TiC增强Fe基和Ni基复合涂层.利用XRD、SEM和EDS研究了复合粉末、涂层的相组成和组织结构,考察了TiC/Fe、TiC/Ni复合涂层的硬度和耐磨性.结果表明: 复合粉末在喷涂过程中反应充分,可分别生成以Fe和Ni为粘结相的TiC增强涂层;两种涂层都是由TiC颗粒均匀分布的复合强化片层和TiC聚集片层叠加而成,TiC/Fe复合涂层的片层较薄,而TiC/Ni涂层中TiC的聚集片层较少;TiC/Fe涂层的硬度高于TiC/Ni涂层,两者的耐磨性能分别约为Ni60涂层的11倍和6倍. 相似文献
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W. H. Lee C. S. Byun S. H. Lee D. K. Kim 《Metallurgical and Materials Transactions A》2001,32(3):805-810
The synthesis of the Ni2Si, Ni5Si2, and NiSi phases has been investigated by mechanical alloying (MA) of Ni-33.3 at. pct Si, Ni-28.6 at. pct Si, and Ni-50 at.
pct Si powder mixtures. As-received and 60-minute premilled elemental powders were subjected to MA. The average surface area
of the premilled Ni powder particles, which had a flaky shape, was 3.5 times larger than that of the as-received Ni powder
particles, which had a spherical shape. The as-received Si powder was angular in shape and the mean particle size was 19.1
μm, whereas the mean particle size of the premilled Si powder was 10 μm. A self-propagating high-temperature synthesis (SHS) reaction, followed by a slow solid-state diffusion reaction, was observed
to produce Ni silicide phases during MA of the elemental powders. The reactants and the product, however, coexisted for a
long period of MA time. On the other hand, only the SHS reaction was observed to produce Ni silicides during MA of the premilled
elemental powders, indicating that Ni silicides formed rather abruptly in a short period of MA time. The mechanisms and reaction
rates for the formation of Ni silicides via MA appeared to be influenced by the elemental powder particle size and shape as well as the heat of formation of the products. 相似文献
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W. H. Lee C. S. Byun S. H. Lee D. K. Kim 《Metallurgical and Materials Transactions A》2001,32(13):805-810
The synthesis of the Ni2Si, Ni5Si2, and NiSi phases has been investigated by mechanical alloying (MA) of Ni-33.3 at. pct Si, Ni-28.6 at. pct Si, and Ni-50 at
pct Si powder mixtures. As-received and 60-minute premilled elemental powders were subjected to MA. The average surface area
of the premilled Ni powder particles, which had a flaky shape, was 3.5 times larger than that of the asreceived Ni powder
particles, which had a spherical shape. The as-received Si powder was angular in shape and the mean particle size was 19.1
μm, whereas the mean particle size of the premilled Si powder was 10 μm. A self-propagating high-temperature synthesis (SHS)
reaction, followed by a slow solid-state diffusion reaction, was observed to produce Ni silicide phases during MA of the elemental
powders. The reactants and the product, however, coexisted for a long period of MA time. On the other hand only the SHS reaction
was observed to produce Ni silicides during MA of the premilled elemental powders, indicating that Ni silicides formed rather
abruptly in a short period of MA time. The mechanisms and reaction rates for the formation of Ni silicidesvia MA appeared to be influenced by the elemental powder particle size and shape as well as the heat of formation of the products.
W.H. LEE, Professor, formerly with the School of Metallurgical and Materials Engineering, Kookmin University, Seoul 133-791,
Korea 相似文献
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La1.5Mg17Ni0.5 hydrogen storage materials were prepared by hydriding combustion synthesis (HCS) and mechanical alloying (MA) method respectively. The experimental results show that the hydrogen absorption properties of La1.5Mg17Nio.5 prepared by MA are better than that by HCS. La1.5Mg17Nio.5 prepared by MA can absorb 6.73 mass% hydrogen at 523 K within 1 min, and 4.92 mass% hydrogen at 423 K. The improvement of hydriding properties of La1.5Mg17Ni0.5alloy prepared by MA can be ascribed to the formation of nano-crystalline and defects during the mechanical alloying. 相似文献
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Fabrication of TiC/Fe–Ni cermet coatings by reactive thermal spraying of Fe–Ti–Ni–C composite powder
《粉末冶金学》2013,56(3):231-235
AbstractA mixture of ferrotitanium, nickel powders and sucrose was heated with an intention of carbonising the sucrose. The tiny ferrotitanium, nickel particles are bound by the carbon obtained from pyrolysis of the sucrose to form a unique structure of Fe–Ti–Ni–C composite powder for reactive thermal spraying. The carbon is a reactive constituent as well as the binder in the composite powder. TiC/Fe–Ni cermet coating was prepared by reactive plasma spraying of this powder. A mass of TiC particles were in situ synthesised and uniformly distributed in the Fe–Ni alloy matrix without residuals of raw materials in the coating. The coating is consisted of two different areas: one is the composite area, where lots of spherical fine TiC particles (100–500 nm) are homogeneously distributed within the Fe–Ni alloy matrix; the other is a small fraction of TiC accumulation. The volume fraction of composite area is >87%. 相似文献