Effect of Processing Parameters on Mechanical Properties of Al7175/Boron Carbide (B4C) Composite Fabricated by Powder Metallurgy Techniques

2021 ◽  
Vol 105 ◽  
pp. 8-16
Author(s):  
Guttikonda Manohar ◽  
Krishna Murari Pandey ◽  
Saikat Ranjan Maity

Metal matrix composites attain a significant position in Industrial, defense, structural and automobile applications. To amplify that strategy there is a need to find out the conditional behavior of the composites and enhancing the properties will be mandatory. The present work mainly investigates on the effect of processing parameters like densification rates, sintering temperature, reinforcement content on the microstructure, mechanical properties of the Al7175/B4C composite material fabricated by mechanical milling and powder metallurgy techniques. Results show there is a grain size reduction and refinement in the composite material through ball milling operations and along with that increasing B4C content in the composite powders make milling conditions very effective. Increasing the sintering temperature results in a consistent grain growth along with that porosity level decreases up to a limit and then attain a steady state, the strength of the composites increases with compaction pressures but reinforcements content effects the strength of the material by losing its ductility making it brittle.

2020 ◽  
Vol 20 (10) ◽  
pp. 6482-6488
Author(s):  
Hansang Kwon ◽  
Mart Saarna ◽  
Marc Leparoux

Nano-silicon carbide (nSiC) particle-reinforced aluminium (Al) 6061 alloy matrix composites were fabricated by high-energy ball milling, hot-pressing (HP), and hot-forging (HF). The composite powders were degassed and the composites were synthesised under air and/or vacuum. Mechanical properties of the obtained composite materials were evaluated using various tests, including indentation, compression, four-point bending, and tensile tests as well as by microstructural observations. Different amounts of nSiC were added and the mechanical properties of the obtained composite materials were measured and discussed. The microstructures of the composites depended on the nSiC content and synthesis conditions. The Vickers hardness and tensile strength values of the nSiC reinforced Al 6061 composites were approximately three times higher than that of a pure Al 6061 alloy bulk. The results demonstrated that the small amount of nSiC particles functioned as efficient reinforcement material in the Al 6061 alloy matrix composite material and that the strength and ductility of the composite material can be controlled by adjusting the processing parameters and nSiC content.


2013 ◽  
Vol 551 ◽  
pp. 161-179 ◽  
Author(s):  
Leandro Bolzoni ◽  
N. Hari Babu ◽  
E.M. Ruiz-Navas ◽  
Elena Gordo

The Ti-6Al-7Nb alloy was specially developed to replace the well-known Ti-6Al-4V alloy in biomedical applications due to supposed cytotoxicity of vanadium in the human body. This alloy is normally fabricated by conventional ingot metallurgy by forging bulk material. Nevertheless, powder metallurgy techniques could be used to obtain this alloy with specific properties. This is because by changing the processing parameters, such as the sintering temperature, it is possible to vary the porosity level and to tailor the final properties. This work deals with the production of the Ti-6Al-7Nb alloy by means of the master alloy addition variant of the blending elemental approach. The powder is processed by means of different powder metallurgy routes considering diverse processing conditions for each method. The materials are characterised in terms of microstructural features, relative density and hardness. Homogeneous microstructures as well as properties comparable to those of the wrought alloy are generally obtained.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5021
Author(s):  
Haiyao Cao ◽  
Zaiji Zhan ◽  
Xiangzhe Lv

Gadolinia (Gd2O3) is potentially attractive as a dispersive phase for copper matrix composites due to its excellent thermodynamic stability. In this paper, a series of 1.5 vol% nano-Gd2O3/Cu composites were prepared via an internal oxidation method followed by powder metallurgy in the temperature range of 1123–1223 K with a holding time of 5–60 min. The effects of processing parameters on the microstructure and properties of the composites were analyzed. The results showed that the tensile strength and conductivity of the nano-Gd2O3/Cu composite have a strong link with the microporosity and grain size, while the microstructure of the composite was determined by the sintering temperature and holding time. The optimal sintering temperature and holding time for the composite were 1173 K and 30 min, respectively, under which a maximum ultimate tensile strength of 317 MPa was obtained, and the conductivity was 96.8% IACS. Transmission electron microscopy observations indicated that nano-Gd2O3 particles with a mean size of 76 nm formed a semi-coherent interface with the copper matrix. In the nano-Gd2O3/Cu composite, grain-boundary strengthening, Orowan strengthening, thermal mismatch strengthening, and load transfer strengthening mechanisms occurred simultaneously.


Author(s):  
M. F. M. Tajudin ◽  
A. H. Ahmad ◽  
M. M. Rashidi

This paper highlights the effects of pouring temperature and holding time on the mechanical properties of aluminium 6061 semisolid feedstock billets. The semisolid metal feedstock billets were prepared by a direct thermal method (DTM), in which the molten metal was poured into a cylindrical copper mould with a different combination of pouring temperature and holding time before it was solidified in room temperature water. The results show that the sample with pouring temperature slightly above aluminium 6061 liquidus temperature has the lowest porosity, thereby the highest mechanical properties value. The sample with a pouring temperature of 660 °C and holding time of 60 s has the density, tensile strength and hardness properties of 2.701 g/cm3, 146.797 MPa, and 86.5 HV, respectively. Meanwhile, the sample at a pouring temperature of 640 °C and holding time of 20 s has density, tensile strength and hardness properties of 2.527 g/cm3, 65.39 MPa, and 71.79 HV, respectively. The density and fractography tests were conducted to confirm the existence of porosity within the samples. The results from these experimental works suggested that the mechanical properties of DTM semisolid feedstock billet merely depended on processing parameters, which influenced the porosity level within the feedstock billet, thus directly affected their mechanical properties.


2013 ◽  
Vol 765 ◽  
pp. 245-249 ◽  
Author(s):  
Alberto Miranda ◽  
Noe Alba-Baena ◽  
Brian J. McKay ◽  
Dmitry G. Eskin ◽  
Se Hyun Ko ◽  
...  

This study investigates the effect of Cu-Carbon Nanotube (Cu-CNT´s) composite powders on the mechanical properties of an Al-Si9.5-Cu4-Fe1.3 wt.% (LM24) aluminium matrix composite (AMC). Carbon nanotubes (CNT’s) can exhibit exceptional mechanical properties, e.g. stiffness up to 1000 GPa and strength in the order of 100 GPa. In recent years there has been significant scientific interest in improving properties in conventional alloys, via fabricating CNT metal matrix composites in order to attempt to harness their extraordinary attributes. In this study mechanically alloyed Cu-CNTS powders were added to molten LM24. The melt was processed using ultrasonic cavitation and subsequently high pressure die casting to form as-cast tensile specimens. SEM results indicate that CNT’s can be successfully introduced into the melt using this method. Compared to the unreinforced alloy, the CNT additions resulted in an increment (~20±10 MPa) to both ultimate tensile strength and yield strength, with a corresponding decline (~1±0.5l %) in elongation. This observed increase in strengthening may be attributed to the CNT’s pinning and hindering both grain boundary and dislocation migration during applied loading. Interestingly, no significant difference in properties were found with an increase in the CNT content (from 0.05 to 0.1 wt.%) potentially indicating a saturation limit.


2004 ◽  
Vol 13 (1) ◽  
pp. 096369350401300 ◽  
Author(s):  
D. Busquets-Mataix ◽  
N. Martvnez ◽  
M.D. Salvador ◽  
V. Amigσ

Mechanical properties and tribological behaviour of AA6061 and AA7015 aluminium matrix composites reinforced with Ti3Al intermetallics have been studied. Processing of the composites consisted of a combination of powder metallurgy and extrusion techniques. High tensile strength was attained on both alloys, although composites did not improve these properties. Also ductility was impaired on composites, but values above 10% were obtained in every case. Regarding friction coefficient, all composites showed a lower value with respect to base alloys, being lower as the amount of reinforcement increased. Wear behaviour of composites was improved.


2013 ◽  
Vol 465-466 ◽  
pp. 886-890
Author(s):  
Adibah Amir ◽  
Othman Mamat

Tronohs raw sand was converted into fine silica particles via a series of milling process. Addition of these fine particles into iron composite was found to modify its mechanical properties. The composite was prepared using powder metallurgy technique with varying percentage of silica particles; 5, 10, 15, 20 and 25wt%. The composites were sintered at three different temperatures; 1000° C, 1100° C and 1200° C to find the most suitable sintering temperature. Changes in density and hardness were observed. The results showed that composite consist of 20wt% silica particles and sintered at 1100° C exhibits best improvement.


2014 ◽  
Vol 32 (2) ◽  
pp. 145-156 ◽  
Author(s):  
J. Judes ◽  
V. Kamaraj

AbstractIn order to overcome limitations in the processing parameters of powder compaction method, a novel processing technique based on sol-gel route has been developed to produce near-net-shaped prototype fine zirconia minispheres with required properties that could potentially be used as grinding media. Impact of magnesia concentration and sintering temperature on the final product has been analyzed in detail. Zirconia minispheres have been characterized to establish a correlation between physical, structural and mechanical properties. Sintering temperature, soaking period, heating rate and viscosity of the sol apparently influence the characteristics of the magnesia stabilized zirconia minispheres. The phase identification, density variation, chemical decomposition, functional group specification, surface area, porosity, shrinkage and microstructural features of the dried and sintered final product have been studied. It has been observed that magnesia content, sintering temperature, density and the grain size of the sintered minispheres have a significant impact on the mechanical properties of the final product.


Author(s):  
M. A. Salem ◽  
I. G. El-Batanony ◽  
M. Ghanem ◽  
Mohamed Ibrahim Abd ElAal

Different Al-SiC metal matrix composites (MMCs) with a different matrix, reinforcement sizes, and volume fractions were fabricated using ball milling (BM) and powder metallurgy (PM) techniques. Al and Al-SiC composites with different volume fractions were milled for 120 h. Then, the Al and Al-SiC composites were pressed under 125 MPa and finally sintered at 450 °C. Moreover, microsize and combination between micro and nano sizes Al-SiC samples were prepared by the same way. The effect of the Al matrix, SiC reinforcement sizes and the SiC volume fraction on the microstructure evolution, physical and mechanical properties of the produced composites was investigated. The BM and powder metallurgy techniques followed by sintering produce fully dense Al-SiC composite samples with different matrix and reinforcement sizes. The SiC particle size was observed to have a higher effect on the thermal conductivity, electrical resistivity, and microhardness of the produced composites than that of the SiC volume fraction. The decreasing of the Al and SiC particle sizes and increasing of the SiC volume fraction deteriorate the physical properties. On the other hand, the microhardness was enhanced with the decreasing of the Al, SiC particle sizes and the increasing of the SiC volume fraction.


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