共查询到19条相似文献,搜索用时 234 毫秒
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TiCNi/Al自蔓延反应热压复合涂层的制备 总被引:1,自引:0,他引:1
采用自蔓延反应热压工艺,在铝合金表面制备了TiCNi金属陶瓷基复合材料涂层.分析了TiCNi金属陶瓷SHS反应热压加压时间、混粉工艺、元素比和粉末颗粒尺寸、预制块密度、反应热压温度、反应热压压力大小、涂层厚度等SHS反应热压工艺参数对涂层与基体间界面结合状态和涂层组织的影响.观察和测试了其显微组织、热震性能以及显微硬度.结果表明,TiCNi涂层与基体Al实现了冶金结合.并分析了TiCNi/Al反应热压复合过程中,涂层内部及涂层与基体之间发生多级自蔓延高温合成反应机制,从而揭示了TiCNi/Al自蔓延反应热压复合机理. 相似文献
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静态自蔓延高温合成法形成陶瓷涂层的研究 总被引:1,自引:0,他引:1
采用静态自蔓延高温合成法(SHS法)在钢件表面形成陶瓷涂层。涂层的相组成主要是Al2O3+(α-Fe)+少量Fe3Al;涂层由两层组成,外层为近乎纯Al2O3陶瓷层,过渡层为(α-Fe)+ Al2O3金属-陶瓷层,两层组织皆为长轴近似垂直于钢件表面的柱状晶;涂层与基体结合牢固。 相似文献
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采用自蔓延高温合成法制备了Ni3Si-Cr7C3和Ni17.5Si29.3Cr两种Ni3Si基复合涂层,研究了两种涂层材料的相组成和微观结构。结果表明,两种涂层材料的基体相均为高温相β3-Ni3Si;同时由于后者具有更高的绝热温度,其晶粒尺寸显著小于前者,从而使Ni17.5Si29.3Cr合金涂层具有更高的显微硬度。摩擦学研究表明,两者在干摩擦和水润滑条件下的磨损机理相似,但是在硫酸溶液条件下由于发生了不同的摩擦化学反应,因此其磨损机理不同,后者具有更好的抗磨损性能。 相似文献
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自蔓延高温合成MoSix/Cu复合材料中MoSix相的原位合成机理 总被引:1,自引:0,他引:1
采用自蔓延高温合成(SHS)技术制备了四组不同成分的MoSix/Cu复合材料.结合XRD、SEM和EDS等分析手段对所制备的MoSix/Cu复合材料显微组织和相组成进行了分析.系统研究了MoSi2设计含量及Mo/Si原子比对复合材料相组成的影响,并在此基础上讨论了MoSix/Cu复合材料中MoSix的原住合成机制.结果表明,MoSix/Cu复合材料相组成包含固溶体相α-Cu、α-Mo、MoSix和CuxSi四类相;随着MoSi2预设含量的增加和Mo/Si原子比的降低,MoSix/Cu复合材料中MoSix和CuxSi相的含量明显增加;自蔓延高温合成MoSix/Cu复合材料中MoSix相的原位合成机制为富Cu、Si的残余液相与其所包围的α-Mo之间通过界面反应直接形成MoSix. 相似文献
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工艺参数对SHS-铸造钢基表面TiC-Fe梯度复合涂层结构的影响 总被引:16,自引:1,他引:16
将自蔓延高温合成(SHS)技术与铸造工艺结合起来,制备了铸造钢基表面TiC—Fe梯度复合材料,研究了钢液的浇注温度、TiC—Fe预制块的组成及其相对密实度等工艺参数对梯度复合涂层结构的影响。结果表明:在保证预制块能被浇注的钢液直接点燃的条件下,适当提高钢液的浇注温度、降低预制块的密实度均有利于梯度复合涂层的形成;而且在预制块中掺加适量的低熔点金属稀释剂不仅可降低合成TiC颗粒的尺寸,而且也有利于梯度复合涂层的形成。梯度复合涂层的形成与钢液向预制块中的渗透、预制块中Fe和低熔点稀释剂的熔化以及合成的TiC颗粒向钢液中的扩散等作用有关。 相似文献
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以Al、TiN、B_4C、Si为原材料,采用自蔓延高温合成热等静压(SHS/HIP)技术制备了AlN-TiN-TiB_2复相导电陶瓷,测定其相对密度、维氏硬度、抗弯强度和断裂韧度等力学性能,并确定了最佳原料比.利用XRD、SEM分析了AlN-TiN-TiB_2复相导电陶瓷的物相和显微组织,材料的断裂模式主要是沿晶断裂.并且研究了不同比例复相陶瓷在不同温度下的电阻率. 相似文献
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Satyajit Chatterjee G. Padmanabham A. Roy Choudhury 《Surface & coatings technology》2010,205(1):131-138
A nanostructured, hard and wear resistant composite coating of Al2O3, TiB2 and TiN isformed on low carbon steel (AISI 1025) substrate by combined self-propagating high-temperaturesynthesis (SHS) and laser surface alloying (LSA). A precursor powder mixture of Al, TiO2 and hBNpreplaced on the substrate surface undergoes self-propagating high-temperature synthesis (SHS) atthe high temperatures induced by the incidence of laser. The products of SHS are subsequently laseralloyed onto the substrate to form the coating. The high power laser beam is again made to pass overthe coating with a view to remelt the coating top layer. This laser post-treatment causes distinct enhancements in microhardness and tribological performance by the modification of themicrostructure of top portion of the coating. 相似文献
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自蔓延烧结在金刚石制品中的应用 总被引:1,自引:1,他引:0
本文主要介绍了自蔓延高温合成技术的发展和特点,阐述了自蔓延高温合成技术在金刚石制品工业中应用的必要性和意义,分析了自蔓延高温合成技术在金刚石制品工业中应用的可行性,并介绍了国内外的应用研究现状,提出了自蔓延高温合成技术在超硬材料制品中的应用需要进一步研究解决的问题。 相似文献
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The bulk Al-12 Si eutectic composites were fabricated through a conventional liquid metal casting route, especially with the help of ultrafine ceramic powders made by self-propagating high-temperature synthesis (SHS) process. The SHS powders were fabricated by the chemical reaction between micro-sized SiC and Al particles at very high combustion temperatures, producing the coarse Al particles (several tens of microns) containing ultrafine SiC ceramic particles. Microstructural observation revealed that the ... 相似文献
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FENG Peizhong QU Xuanhui Akhtar Farid S.H. Islam 《稀有金属(英文版)》2006,25(3):225-230
MoSi2 is presently regarded as the most important material for electrical heating and as one with huge potential for high temperature structural uses. MoSi2 and MoSi2 matrix composites were prepared by self-propagating high temperature synthesis (SHS). Pure MoSi2 was obtained and a compound of MoSi2 and WSi2was synthesized in the form of predominant solid solution (Mo,W)Si2. By adding aluminum of 5.5 at.% to Mo-Si, the crystal structure of MoSi2 changed into a mixture of tetragonal Cllb MoSi2and hexagonal C40 Mo(Si,Al)2. The (Mo,W)Si2-Mo(Si,Al)2-W(Si,Al)2 composite materials were synthesized by adding aluminum of 5.5 at.% to Mo-W-Si. However, if the amount of the added aluminum was not larger than 2.5 at.%, it did not have any significant effect. SHS is an effective technology for synthesis of MoSi2 and MoSi2 matrix composites. 相似文献
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《Intermetallics》2006,14(10-11):1270-1275
A novel method to process intermetallic coatings by using a high flux solar concentrator has been studied. The main aim was to initiate an exothermic reaction in a mixture of powders (Ni and Al) and to obtain high quality coatings (NiAl) through a solar assisted SHS (self-propagating high temperature synthesis) process. Coatings have been processed in the form of tracks by scanning a concentrated solar beam across the specimen surface, thus modifying larger surfaces than those achieved with stationary treatment. Concentrated solar energy (CSE) not only provided the necessary heat to initiate the reaction but also permitted the propagation of the reaction through a reactant mixture of powders. This novel coating technology which combines SHS and CSE allows synthesizing the intermetallic coating in situ employing an energy saving process. By choosing an appropriate beam–sample interaction time it was possible to obtain homogenous, adherent and low porosity NiAl coatings. 相似文献
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反应火焰喷涂三元硼化物金属陶瓷涂层的组织和性能 总被引:6,自引:4,他引:6
反应喷涂是近年来发展的一种制备陶瓷/金属复合涂层的新技术,它是将自蔓延高温合成与普通的热喷涂技术相结合,在合成材料的同时使合成材料沉积,陶瓷相为原位合成,晶粒细小,与金属基体之间结合良好.采用反应火焰喷涂方法在45钢表面制备Mo2FeB2三元硼化物金属陶瓷涂层,分析了粉末团聚方式对涂层显微组织的影响,测试了涂层的显微硬度及耐磨性能.结果表明:团聚粉末经过火焰喷涂获得Mo2FeB2三元硼化物金属陶瓷涂层,其显微硬度达到1 200HV0.1,具有良好的耐磨性能. 相似文献