scholarly journals Evaluation of Microstructure, Hardness, and Tensile Properties: A Comparative Study of Stir Cast and Extruded Al7005/Glass-/Fly-Ash-Reinforced Hybrid MMCs

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Praveen Kumar Swamy ◽  
Shantharaja Mylaraiah ◽  
Dadapeer Basheer

The effect of extrusion ratio and addition of glass and fly ash on microstructural, mechanical properties, and fracture behavior of Al composites is examined. Both the composites and hybrid composites are prepared by the liquid metallurgical technique. Microstructure, extrusion effect on hardness, tensile properties, and fracture are studied using an optical micrograph, hardness tester, Universal Testing Machine, and scanning electron microscope, respectively. Experimental results show that increasing the extrusion ratio leads to a significant enhancement in mechanical properties such as tensile, compression, and yield strength and Young’s modulus, but results in a small reduction of ductility. It has been revealed that the presence of glass and fly ash improve the mechanical properties significantly with a slight reduction in ductility compared to the Al alloy. Fracture behaviour of the base alloy and composites show intergranular ductile and brittle cleavage mode failure as observed by SEM.

2017 ◽  
Vol 47 (8) ◽  
pp. 2050-2073 ◽  
Author(s):  
A Praveen Kumar ◽  
M Nalla Mohamed

Economic and environmental concerns lead the researchers toward development of sustainable and renewable materials of which reinforced composites are part of. The abundantly available natural fibers have attracted the researchers to study their performance as reinforcements and feasibility for making automobile components. The performance of composite materials is mainly assessed through their mechanical properties. However, natural fibers to date were mainly used as reinforcements to create bulk composite components with reduced cost rather than improved mechanical performances. Among the methods available for improving mechanical properties of the natural fiber composites, combined mercerization treatment, hybridization, and incorporation of fly ash fillers in the matrix are the best solutions. Therefore, the objective of this research is to evaluate the tensile properties of hybrid kenaf/glass composites with and without fly ash particulate filler as per ASTM standards. Moisture absorption behavior and its effect on the tensile properties of hybrid composites are also investigated. The results revealed that the addition of 10wt % fly ash particles with natural fiber composites increased the tensile strength of composites while hybridization with glass fibers reduced the water absorption properties.


2013 ◽  
Vol 20 (4) ◽  
pp. 343-350 ◽  
Author(s):  
Pandian Amuthakkannan ◽  
Vairavan Manikandan ◽  
Jebbas Thangaiah Winowlin Jappes ◽  
Marimuthu Uthayakumar

AbstractMechanical properties of fiber reinforcement that can be obtained by the introduction of basalt fibers in jute fiber-reinforced polyester composites have been analyzed experimentally. Basalt/jute fiber-reinforced hybrid polymer composites were fabricated with a varying fiber percentage by using compression molding techniques. The fabricated composite plates were subjected to mechanical testing to estimate tensile strength, flexural strength and impact strength of the composites. The effect of fiber content on basalt/jute fiber in the composites has been studied. Addition of jute fiber into basalt fiber composite makes it a cost-effective one. Incorporation of basalt fiber into the composites was at approximately 10%, 20%, up to 90%, and the jute fiber percentage was reduced from 90%, 80%, to 10% correspondingly. Mechanical properties were investigated as per ASTM standards. Tensile and flexural strengths were tested by using a computer-assisted universal testing machine, and impact strength by using an Izod impact tester. It has been observed that the addition of jute fiber to the basalt fiber polyester composites enhanced the mechanical properties. Water absorption of hybrid composites was also analyzed and was found to be proportional to fiber percentage.


2014 ◽  
Vol 794-796 ◽  
pp. 71-76 ◽  
Author(s):  
Anilchandra R. Adamane ◽  
Elena Fiorese ◽  
Giulio Timelli ◽  
Franco Bonollo ◽  
Lars Arnberg

Aluminium-Silicon (Al-Si) alloys are the most extensively used Al foundry alloys and are widely used in gravity die-casting (GDC) of automotive components. Reference dies are used to characterize the tensile properties of the castings. Among the various die configurations, the ASTM B-108 (also called the Stahl Mold), and the AA Step Mold are most popular in the foundries. Several modifications to the standard dies have been suggested in the scientific literature to obtain better mechanical properties in minimizing casting defects. This work reviews the scientific literature on the effect of different reference dies on the porosity and tensile properties of the Al alloy castings.


1974 ◽  
Vol 96 (3) ◽  
pp. 201-206 ◽  
Author(s):  
M. W. Mahoney ◽  
N. E. Paton

Uniaxial tensile properties of the niobium-base alloy Cb-752 have been determined as a function of oxygen, nitrogen, and hydrogen content over a temperature range of −196 C to 200 deg C. Each of these impurities increased the temperature at which a ductile-brittle transition occurs. Although ductility was severely reduced, strength parameters were relatively unchanged making detection of embrittlement by hardness testing difficult. Impurity levels for embrittlement were sufficiently low and the affinity of Cb-752 for contamination sufficiently great that processing operations require strict control. The mechanism of this impurity embrittlement is not well understood. However, observations of fracture surfaces of brittle failures reveal mixed intergranular cleavage with a uniform distribution of precipitates throughout grain boundaries. These observations are discussed in the light of current theories.


2017 ◽  
Vol 7 (1.1) ◽  
pp. 193
Author(s):  
M.H. Faisal ◽  
S. Prabagaran ◽  
T.S. Vishnu

Aluminium/graphite composites are the need of modern times for addressing the fuel saving issues. The graphite in such composites act as solid lubricant and it reduce external fuel requirements. But such composites are having degraded mechanical properties due to the graphite content in composite. In order to solve the negative effect of graphite on mechanical properties of LM13/Gr self-lubricating composite this study was conducted to find out the mechanical properties of LM13/B4C/Gr Metal Matrix Composites. Boron carbide was selected as reinforcement because of its better reinforcement properties compared to alumina and silicon carbide. The properties of the hybrid composites were compared with the LM13/Gr self-lubricating composite to study the enhancement in mechanical properties that has been caused by the boron carbide particles. Using computerized universal testing machine and rock-well hardness tester mechanical properties such as hardness and tensile strength were tested. Pin on disk testing machine was used to analyse the wear behavior. The test results indicates that by raising weight % of boron carbide particles in the LM13, tensile strength and hardness of the hybrid composites was increased compared to self-lubricating composite accompanied by better tribological properties.


2019 ◽  
Vol 31 (11) ◽  
pp. 2537-2542
Author(s):  
A. Sharma ◽  
S.K. Sharma ◽  
A. Rani

Polyethylene glycol based polyurethane polymer and its fly ash reinforced polyurethane composite were prepared by optimizing the concentration ratio of binders, cross linking agents and curing agents. The components ratio of cross linking agents with the same hydroxyl functionalities i.e. 1,4-butane diol and 1,1,1-trimethylol propane affects the mechanical properties of polymer. The extent of polymerization of polyurethane matrix and fly ash reinforced polyurethane composite was found to be independent of the component ratio of cross linking agents. PEG based polyurethane polymer and their fly ash-reinforced composite can be synthesized at particular ratio by mass of cross linking agents i.e. 0.5 keeping constant w/w ratio 3:2 of binders and curing agents. Effect of w/w ratio variation of cross linking agents on the extent of polymerization has been studied through SEM technique. Cross linking agents, curing agents and polyurethane composite have been characterized by IR spectra. Effect of w/w ratio variation of binary components 1,4-butane diol and 1,1,1-trimethylol propane of cross linking agents on the mechanical properties of fly ash-reinforced polyurethane composite has been studied by evaluating tensile strength and Young modulus of composite material by universal testing machine. Hardness of fly ash-reinforced polyurethane composite with different ratio of 1,4-butane diol and 1,1,1-trimethylol propane of cross linking agents was evaluated by durometer


2019 ◽  
Vol 100 (1) ◽  
pp. 29-35 ◽  
Author(s):  
T. Ram Prabhu ◽  
M. Murugan ◽  
B. P. Chiranth ◽  
R. K. Mishra ◽  
N. Rajini ◽  
...  

2014 ◽  
Vol 984-985 ◽  
pp. 546-550
Author(s):  
K. Umanath ◽  
S.T. Selvamani ◽  
K. Palanikumar ◽  
Ram G. Dinesh

Metal to the metal wear analysis of Aluminium (Al6061grade) alloy, dis-continuously reinforced with ceramic particles of SiC and Al2O3deliver this paper. The Al matrix with 5 to 25% of vol. Fractions of SiC and Al2O3particulate reinforcements were formed in Hybrid Metal Matrix Composite (HMMC) by stirring casting technology. They are finding applications in automotive, aeronautical and sport goods. For the proper use of these composites, its mechanical properties and wear properties are to be evaluated. The dry sliding behavior of these SiC and Al2O3particulates HMMCs and that of Al alloy at atmosphere was analyzed with a pin on disc type wear testing machine. The result indicates that, the scanning electron micrographs of the worn surfaces of the hybrid composites show the worn surface of the composite alloy is rougher than the unreinforced Al6061alloy.


In this work hot extrusion of hybrid composites of Al6061/SiC/Gr was carried out at ratios of 2:1,3:1&4:1 & temperatures of 4500 ,5000 ,&5500 c at various compositions of 0,2,4,6 &8 % of SiC and fixed amount of graphite i.e 2% using 200 tonn capacity press at a speed of 1mm/sec to investigate mechanical properties like tensile, compression & BHN and after solutionising and aging .It was found that at ratio 3:1 and temperature 5000 c all the above three properties were found to be improved compared to extrusion .


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