Microstructure Characteristics and Mechanical Properties of In Situ TiB/Ti Composites Prepared by Arc-Melting Technique

2014 ◽  
Vol 881-883 ◽  
pp. 867-871
Author(s):  
Ji Fang Lu ◽  
Zhao Hui Zhang ◽  
Fu Chi Wang

In this paper, in situ TiB reinforced Ti-3Al, Ti-6Al and Ti-6Al-4V matrix composites were prepared by arc-melting technique utilizing the reaction between Ti and TiB2, and then forged in the α+β phase field. Phase identification was carried out via X-ray diffraction. Microstructure of the composites was studied by optical microscopy (OM) and scanning electron microscopy (SEM). Mechanical properties of the composites after forging were measured at various temperatures by tensile experiment. The results showed that Ti-6Al-4V-2TiB composite exhibits fine equiaxed matrix microstructure with a grain size of 5-10μm. The tensile strength and elongation of the composite at room temperature reached 1069MPa and 10.0%, respectively.

2011 ◽  
Vol 172-174 ◽  
pp. 190-195 ◽  
Author(s):  
Giorgia T. Aleixo ◽  
Eder S.N. Lopes ◽  
Rodrigo Contieri ◽  
Alessandra Cremasco ◽  
Conrado Ramos Moreira Afonso ◽  
...  

Ti-based alloys present unique properties and hence, are employed in several industrial segments. Among Ti alloys, β type alloys form one of the most versatile classes of materials in relation to processing, microstructure and mechanical properties. It is well known that heat treatment of Ti alloys plays an important role in determining their microstructure and mechanical behavior. The aim of this work is to analyze microstructure and phases formed during cooling of β Ti-Nb-Sn alloy through different cooling rates. Initially, samples of Ti-Nb-Sn system were prepared through arc melting furnace. After, they were subjected to continuous cooling experiments to evaluate conditions for obtaining metastable phases. Microstructure analysis, differential scanning calorimetry and X-ray diffraction were performed in order to evaluate phase transformations. Depending on the cooling rate and composition, α” martensite, ω phase and β phase were obtained. Elastic modulus has been found to decrease as the amount of Sn was increased.


Author(s):  
Memduh Kara ◽  
Tolga Coskun ◽  
Alper Gunoz

Aluminum is a material with advantageous properties such as lightness, good conductivity, high plastic deformation ability, and superior corrosion resistance. However, aluminum and many aluminum alloys have disadvantages in terms of mechanical properties such as hardness, tensile strength, and wear resistance. To overcome this disadvantage of aluminum, it is a good method to add ceramic particles to the matrix. For this purpose, in this study, B4C (boron carbide)-reinforced AA2014 aluminum matrix composites were fabricated at 3%, 5%, and 7% reinforcement ratios using the stir casting method. Tensile tests, wear tests, cutting force measurements, and microhardness measurements were performed to determine the fabricated composite materials’ mechanical properties. Scanning electron microscopy and optical microscopy were used to analyze the microstructure of composite. X-ray diffraction analysis was utilized to study the phase identification. As a result of the study, it was observed that with the increase in the B4C reinforcement ratio, the mechanical properties of the aluminum matrix composite material, such as wear resistance, cutting strength, and hardness, increased. On the other hand, the change in tensile strength did not occur in this way. Tensile strength first increased and then decreased. The highest value of tensile strength was achieved at 5% B4C reinforcement. X-ray diffraction results showed that AA2014 and B4C were the fundamental elements in composites and are free from intermetallics.


2012 ◽  
Vol 217-219 ◽  
pp. 71-74
Author(s):  
Jing Wang ◽  
Si Jing Fu ◽  
Shu Yong Jiang ◽  
Hong Cheng

Iron matrix composite reinforced with VC reinforcements was produced by in situ synthesis technique. The microstructure of the composites was characterized by X-ray diffraction and scanning electron microscopy. The micrographs revealed the morphology and distribution of the reinforcements. The results show that the composite consists of VC carbide as the reinforcing phase and α-Fe as the matrix. The distribution of spherical VC particulates in iron matrix is uniform, and the matrix microstructure of Fe-VC composite is pearlite.


Author(s):  
Sarwar Ibrahim Saleh ◽  
Musa Gögebakan ◽  
M. S. Omar ◽  
Hakan Yaykasli ◽  
Celal Kursun ◽  
...  

Introduction: The Al 85-Ni15 alloy with 99.99% purity of Al and Ni were prepared by an arc melting technique system. The annealing effect onthe microstructure properties, phase transformation and micro-hardness for the Al-Ni alloy system were investigated. Material and Methods:The alloys were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Differential Thermal Analysis (DTA) as well as Vickers micro-hardness measurement. Results and Discussion: The quantitative results confirm that the chemical composition of the alloys is very close to compositions and the microstructures are in typical lamellar morphology. Mechanical properties for the as-prepared samples and subsequently heat-treated samples were measured by a Vickers indenter. Values of the micro-hardness (HV) Conclusions: According the XRD pattern analysis a multi phases produced, such as Al, AlNi3in room temperature, Al3Ni2, Al0.42Ni0.58 at 200ºC, Al1.1Ni0.9 at 300ºC and Al 0.802Ni0.198, AlNi3 and AlNi at 400ºC, and Al0.802Ni0.198, AlNi3 and AlNi for 500ºC. Similar approached were obtained from the results of SEM and DTA measurements. Annealing treatments are visibly affecting the alloy phase formation with different phases at different temperature. and the elastic modulus (E) of the as prepared sample are 132.9±0.1 kgfmm-2 (1.329±0.1 GPa) and 80.340±0.1 GPa, respectively. Furthermore, the characteristic of the materials plasticity (δH) value was calculated to be 0.85. The micro-hardness values are decrease with the increase of annealing temperatures.


2015 ◽  
Vol 1085 ◽  
pp. 307-311 ◽  
Author(s):  
Yurii Sharkeev ◽  
Zhanna G. Kovalevskaya ◽  
Qi Fang Zhu ◽  
Margarita A. Khimich ◽  
Evgeniy A. Parilov

The results of investigation of the structure, physical and mechanical properties of the Ti-Nb alloy ingots with different composition obtained by arc melting are presented. X-ray diffraction and microstructural analyses were used. Microhardness was measured and the Young’s modulus of the alloys was evaluated. When the content of niobium in the alloy changes from 10 to 40 mass.%, phase composition of the alloy varies from α-and α'-phase (10 mass.% of Nb) to α'-, α''- and β-phases (25 mass.% of Nb), to the β-phase (40 mass.% of Nb). The alloy containing 40 mass.% Nb has the lowest Young’s modulus.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1479-1484 ◽  
Author(s):  
JONGHOON KIM ◽  
BONGGYU PARK ◽  
YONGHO PARK ◽  
IKMIN PARK ◽  
HEESOO LEE

Intermetallic matrix composites reinforced with ceramic particles have received a great deal of attention. Iron aluminide is known to be a good material for the matrix in such composites. Two processes were used to fabricate FeAl - TiB 2 intermetallic matrix composites. One was liquid melt in-situ mixing, and the other was arc melting and suction casting processes. FeAl - TiB 2 IMCs obtained by two different methods were investigated to elucidate the influence of TiB 2 content. In both methods, the grain size in the FeAl alloy decreased with the presence of titanium diboride. The grain size of in-situ FeAl - TiB 2 IMCs became smaller than that of arc FeAl - TiB 2 IMCs. Significant increase in fracture stress and hardness was achieved in the composites. The in-situ process gives clean, contamination-free matrix/reinforcement interface which maintained good bonding causing high load bearing capability. This contributed to the increase in the mechanical properties of composites.


2018 ◽  
Vol 60 (12) ◽  
pp. 1221-1224 ◽  
Author(s):  
Balachandran Gobalakrishnan ◽  
P. Ramadoss Lakshminarayanan ◽  
Raju Varahamoorthi

2015 ◽  
Vol 787 ◽  
pp. 583-587 ◽  
Author(s):  
V. Mohanavel ◽  
K. Rajan ◽  
K.R. Senthil Kumar

In the present study, an aluminum alloy AA6351 was reinforced with different percentages (1, 3 and 5 wt %) of TiB2 particles and they were successfully fabricated by in situ reaction of halide salts, potassium hexafluoro-titanate and potassium tetrafluoro-borate, with aluminium melt. Tensile strength, yield strength and hardness of the composite were investigated. In situ reaction between the inorganic salts K2TiF6 and KBF4 to molten aluminum leads to the formation of TiB2 particles. The prepared aluminum matrix composites were characterized using X-ray diffraction and scanning electron microscope. Scanning electron micrographs revealed a uniform dispersal of TiB2 particles in the aluminum matrix. The results obtained indicate that the hardness and tensile strength were increased with an increase in weight percentages of TiB2 contents.


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