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Microstructure and Mechanical Property of in-situ Al-Cu/TiC Composites
Erlin ZHANG,Songyan ZENG,Bo YANG,Qingchun LIMingzhen MA,

材料科学技术学报 , 1998,
Abstract: An approach named direct reaction synthesis (DRS) has been developed to fabricate particulate composites with an extremely fine reinforcement size. ID situ Al matrix composites were fabri-cated by DRS. Extensive analysis of the composites microstructure using SEM and TEM identify that the reinforcement formed during the DRS process is Ti carbide (TiC) particle, generally less than 1.0 μm. The reacted, semisolid extruded samples exhibit a homogeneous distribution of fine TiC particles in Al-Cu matrix, Mechanical property evaluation of the composites has revealed a very high tensile strength relative to the matrix alloy. Fractographic analysis indicates ductile failure although the ductility and strength are limited by the presence of coarse titanium aluminides (Al3Ti).

W.L. Xu
,Y.S. Sun and S.S. Ding

金属学报(英文版) , 2001,
Abstract: Microstructure and tensile properties of Fe3Al-based alloys with additions of TiC andVC particles have been investigated.Results show that the formation of TiC particlesresults in the refinement of the macrostructure of as-cast ingots.Although the additionof VC particles does not cause significant change of the as-cast microstructure,themicrostructure of the alloy after hot-working and recrystallization has been found tobe refined.The formation of both VC and TiC particles results in the increase of yieldstrength,especially at high temperature of 600℃.
Microstructure and mechanical properties of TiC/Al(7075) composites fabricated by in situ reaction

- , 2017, DOI: 10.13801/j.cnki.fhclxb.20161110.001
Abstract: 采用原位合成法制备TiC/Al(7075)复合材料,研究原位TiC颗粒的存在形式、分布状态及不同原位TiC颗粒含量对TiC/Al(7075)复合材料的微观组织及力学性能的影响。结果显示,TiC颗粒多以近球形团聚态存在于7075铝基体中,颗粒团大小约为1 μm。当原位TiC颗粒质量分数小于6%时,原位TiC颗粒分布较为均匀,随着颗粒含量的增加,TiC/Al(7075)复合材料的铸态组织由蔷薇状组织逐渐转变为等轴晶组织,晶粒尺寸也随着原位TiC颗粒含量的增加而减小。当原位TiC颗粒的质量分数大于6%时,组织中出现气孔。复合材料的硬度和抗冲击韧性测试表明,TiC/Al(7075)复合材料的硬度随TiC颗粒含量的增加而增加,最高硬度达HB 108,冲击韧性在颗粒质量分数为6%时达到最佳,较基体提升31.55%。 TiC/Al(7075) composites were fabricated by in situ reaction. The influence of in situ TiC particles form, distribution state and content on the microstructure and mechanical properties of the TiC/Al(7075) compo-sites were discussed. The results show that most spherical in situ TiC particles with aggregate exists in 7075 matrix, the cluster of grain size is about 1 μm. When the mass fraction of in situ TiC particles is less than 6%, the TiC distribution is more uniform. With the increase of in situ TiC particles, the grain sizes of the TiC/Al(7075) composites decrease significantly. But the porosity appear in the microstrcuture when the mass fraction of in situ TiC particles is more than 6%. Hardness and toughness of composite material testing shows that with the increase of the TiC particle concentration, the highest hardness of the surface reaches HB 108, the composites with 6% TiC have the best toughness, the toughness increases by 31.55% compared with the 7075 matrix. 山西省研究生教育创新项目(2016BY137);晋城市科技计划项目(201501004-13)
Corrosion Behavior of Mg-Al/TiC Composites in NaCl Solution  [PDF]
L. A. Falcon,E. Bedolla B.,J. Lemus,C. Leon,I. Rosales,J. G. Gonzalez-Rodriguez
International Journal of Corrosion , 2011, DOI: 10.1155/2011/896845
Abstract: The corrosion behavior of TiC particles reinforced Mg-Al alloy in 3.5% NaCl solution has been evaluated using electrochemical techniques. Tested alloys included an Mg-9Al (Mg AZ91E) alloy with and without 56?wt. % TiC particles. Electrochemical techniques included potentiodynamic polarization curves, linear polarization resistance, electrochemical noise, and electrochemical impedance spectroscopy measurements. All techniques showed that the composite exhibited a lower corrosion rate than the base alloy. Evidence of galvanic effects that increased the composite corrosion rate was found between the matrix and the TiC particles. Additionally, the tendency to suffer from pitting corrosion was higher for the base alloy than that for the composite. Electrochemical impedance results showed the importance of adsorption/diffusion phenomena in both materials. 1. Introduction Nowadays, aluminum matrixes are widely used in metallic matrix composites (MMCs), because they have the highest priority in applications where a combination of corrosion resistance, low density, and high mechanical performance are required, such as in the automotive and aerospace industry. The reinforcement of an aluminum matrix, based on the use of TiC particles is interesting because of its good wettability [1, 2] which results in a clean and strong interface [2–4]. While aluminum alloys are the most commonly used matrix in metal-ceramic composites, it has been reported that the addition of TiC, as reinforcement, improves the mechanical properties at room and high temperatures. However, research in new systems is required due to rapid increase in technological development. Therefore, it could be appreciated as an increasing interest in the use of magnesium and its alloys as a metallic matrix for MMC composites. The main disadvantage of magnesium is the high chemical reactivity due to its negative electrochemical potential; this greatly restricts its industrial applications, and the same disadvantage has been found for Mg-Al-Zn alloys, being Mg AZ91, the most significant alloy. Researches on metallic-based matrix composites using magnesium are considerable fewer than those done for aluminum [5–10]. Many studies have been carried out to determine the Mg-Al-Zn corrosion behavior. Pardo et al. [11] concluded that corrosion damage was mainly caused by formation of a Mg(OH)2 corrosion layer. AZ80 and AZ91D alloys revealed the highest corrosion resistance. The relatively fine β-phase (Mg17Al12) network and the aluminum enrichment produced on the corroded surface were the key factors limiting
In-situ TiCP/Al Composites Prepared by TE/QP Method
In-situ TiC_P/Al Composites Prepared by TE/QP Method

Mingzhen MA,Riping LIU,Hongli ZHAO,Yifa YU,
Mingzhen MA
,Riping LIUl,Hongli ZHAO and Yifa YU Key Laboratory of Metastable Materials Science & Technology,Yanshan University,Qinhuangdao,China Hengdian Group Xinna Electronic Co.,LTD,Dongyang,China

材料科学技术学报 , 2005,
Abstract: An in-situ TiCP/Al composite was prepared by a thermal explosion/quick pressure method (TE/QP). The effect of Al content on the reaction temperature as well as the reaction rate has been studied. Phase constituents and the microstructure of the composites and the particle size of the reinforcement were analysed using X-ray diffraction (XRD)and scanning electron microscopy (SEM). The results have shown that TiCP/Al composite with 40~70 vol. pct TiC particle reinforcement and high relative density can be directly obtained by TE/QP. TiC is the only reaction product when Al content in Al-Ti-C system is no more than 60 vol. pct, but Al3Ti phase will also form when Al content is more than 60 vol. pct. Increasing Al content prolongs the initial reaction time, reduces the highest reaction temperature and the reaction rate, and decreases the size of TiC particles. In addition, the microstructure of TiCP/Al composite and the structure of interface between TiCP and Al are studied using SEM and transmission electron microscopy (TEM). The results show that the in-situ synthesized TiC particle has fcc cubic structure. The orientation between TiC particles and Al matrix can be described as (220)Al∥(022)TiC and 112]Al∥011]TiC. Results of the mechanical property tests reveal that the ultimate strength (σ) and modulus (E) are 687 MPa and 142 GPa respectively when the Al content is 40 vol. pct. On contrary, δ elongation increases by 3.2% with increasing Al content.

LIU Haozhe,WANG Aimin,WANG Luhong,DING Bingzhe,HU Zhuangqi,

金属学报 , 1997,
Abstract: The TiC particles reinforced Ni3Al intermetallic compound matrix compositeswere in situ synthesized under high temperature (1073-1473 K) and high pressure (1.5-6.5GPa) conditions. The densities of these composites exceed 98% of theoretical value. Themean grain size of TiC particles is nanometer scale. The influence of high pressure on thegrain size, and therefore the effect on the microhardness were discussed.
Microstructure Characteristic of In-situ Ti/TiC Composites

Bo YANG,Erlin ZHANG,Yunxue JIN,Zhaojun ZHU,Songyan ZENG,

材料科学技术学报 , 2001,
Abstract: TiC reinforced titanium composites has been produced with different Al content and C content by XDTM. The results have shown that TiC particles are of two different morphologies f coarse dendritical primary TiC and short bar-shape eutectic TiC. Al content has great effects on the morphology of TiC. With the increasing of Al content, the morphology of primary TiC changes from coarse developed dendrite into short bar-shape or plate--shape TiC with 35%Al. Meanwhile, the structure of the matrix changes from single Ti to Ti and Ti2Al and to Ti3Al. However, the C content has no influence on the microstructure of matrix. When the C content is less than 1.2%, the dendrite TiC disappears and only short bar-shape or plate-shape TiC exists in the composites. In addition, the effect of heat of heat treatment on the morphology of TiC has also studied.
Proeutectic crystallisation in hypereutectic silumins modified with Al-CuP-Me master alloys  [PDF]
J. Pi?tkowski
Archives of Foundry Engineering , 2009,
Abstract: Using thermal analyses TA and ATD, within a narrow range of the crystallisation period, i.e. until reaching an equilibrium temperature, the occurrence of exothermic effect was stated. Most probably, the said effect is due to a proeutectic crystallisation of α phase or of β phase crystals. The said effect was observed to occur only in alloys after the process of modification with an addition of high-melting point elements. Complex inoculants of Al-CuP-Me (Me = Mo, Co, Cr, Nb, TiB, W) type cause hardening of silumins, due to the formation of new phases of the AlxMey type, which can act as substrates for the nucleation of α dendrites and crystals of β phase. The experiments carried out on castings solidifying with different rates of heat transfer have proved that proeutectic crystallisation does not occur when free solidification conditions (microspheres) are provided. This fact can be related to the heat transfer rate.
Fabrication and Characterizations of Mechanical Properties of Al-4.5%Cu/10TiC Composite by In-situ Method  [PDF]
Anand Kumar, Manas Mohan Mahapatra, Pradeep Kumar Jha
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2012, DOI: 10.4236/jmmce.2012.1111113
Abstract: Addition of reinforcement such as TiC, SiC, Al2O3, TiO2, TiN, etc. to Aluminium matrix for enhancing the mechanical properties has been a well established fact. In-situ method of reinforcement of the Aluminium matrix with ceramic phase like Titanium Carbide (TiC) is well preferred over the Ex-situ method. In the present investigation, Al-Cu alloy (series of 2014 Aluminium alloy) was used as matrix and reinforced with TiC using In-situ process. The Metal Matrix Composite (MMC) material, Al-4.5%Cu/10%TiC developed exhibited higher yield strength, ultimate strength and hardness as compared to Al-4.5%Cu alloy. Percentage increase in yield and ultimate tensile strengths were reported to be about 15% and 24% respectively whereas Vickers hardness increased by about 35%. The higher values in hardness indicated that the TiC particles contributed to the increase of hardness of matrix. Fractured surface of the tensile specimen of the composite material indicated presence of dimpled surface, indicating thereby a ductile type of fracture. During the fabrication of composite, reaction products such as Al3Ti, Al2Cu and Al3C4 were identified with various morphologies and sizes in metal matrix.
In-situ observation of porosity formation during directional solidification of Al-Si casting alloys  [PDF]
Zhao Lei,Pan Ye,Liao Hengcheng
China Foundry , 2011,
Abstract: In-situ observation of porosity formation during directional solidification of two Al-Si alloys (7%Si and 13%Si) was made by using of micro-focus X-ray imaging. In both alloys, small spherical pores initially form in the melt far away from the eutectic solid-liquid (S/L) interface and then grow and coagulate during solidification. Some pores can float and escape from the solidifying melt front at a relatively high velocity. At the end of solidification, the remaining pores maintain spherical morphology in the near eutectic alloy but become irregular in the hypoeutectic alloy. This is attributed to different solidification modes and aluminum dendrite interactions between the two alloys. The mechanism of the porosity formation is briefly discussed in this paper.
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