Machinability Studies on Aluminium Matrix Hybrid Composites

2014 ◽  
Vol 894 ◽  
pp. 27-31 ◽  
Author(s):  
T.N. Shridhar ◽  
L. Krishnamurthy ◽  
B.K. Sridhara

Aluminium metal matrix composites due to their excellent properties like high strength to weight ratio and high wear resistant are becoming new generation of materials useful for various engineering applications. A continuing problem with these composites is that they are difficult to machine. Machining of these composites depends on the relative content of the reinforcement and the matrix material as well as on its response to the machining process. Experimental investigations have been carried out on the machinability aspects of Aluminium hybrid composites reinforced with Graphite and Silicon Carbide particulates. Experiments have been carried out by Design of Experiments approach. Mathematical models which correlate the interactive and higher order influences of cutting parameters on the resultant force have been developed.

2020 ◽  
Vol 4 (2) ◽  
pp. 115-126
Author(s):  
Anil K. Matta ◽  
Naga S. S. Koka ◽  
Sameer K. Devarakonda

Magnesium Metal Matrix Composites (Mg MMC) have been the focus of consideration by many researchers for the past few years. Many applications of Mg MMCs were evolved in less span of time in the automotive and aerospace sector to capture the benefit of high strength to weight ratio along with improved corrosion resistance. However, the performance of these materials in critical conditions is significantly influenced by several factors including the fabrication methods used for processing the composites. Most of the papers addressed all the manufacturing strategies of Mg MMC but no paper was recognized as a dedicated source for magnesium composites prepared through stir casting process. Since stir casting is the least expensive and most common process in the preparation of composites, this paper reviews particulate based Mg MMCs fabricated with stir casting technology. AZ91 series alloys are considered as the matrix material while the effect of different particle reinforcements, sizes , weight fractions on mechanical and tribological responses are elaborated in support with micro structural examinations. Technical difficulties and latest innovations happened during the last decade in making Mg MMCs as high performance material are also presented.


2020 ◽  
Vol 70 (2) ◽  
pp. 167-180
Author(s):  
Vennapusa Vijaya Bhaskar ◽  
Kolla Srinivas ◽  
Devireddy Siva Bhaskara Rao

AbstractThe present work addresses the physical and mechanical properties of banana and palmyra fiber reinforced epoxy composites with the aim of study on the effect of weight ratio and fiber percentage. The banana and palmyra fibers were arranged with different weight ratios (1:1, 1:3, and 3:1) and then mixed with the epoxy matrix by hand lay-up technique to prepare the hybrid composites with various fiber percentages (10%, 20%, 30% and 40%). The properties are measured by testing its density, water absorption, tensile strength, impact strength, hardness and flexural strength and compared. From the results, it was indicated that addition of banana and palmyra fiber in to the matrix material up to 30% by fiber percentage results in increasing the mechanical properties and slightly variation with weight ratios. Interfacial analysis of the hybrid composites were also observed by using scanning electron microscope (SEM) to study the internal failures and micro structure of the tested specimen.


Author(s):  
P. V. Rajesh ◽  
M. Sriram Prasanth ◽  
V. Sam Daniel ◽  
C. M. Saravanan

Aluminium Matrix Composites are extensively used due to their desirable properties like low weight, low cost, high strength to weight ratio, good corrosion resistance, good thermal conductivity and high stiffness. Their applications are diversified in production, thermal, marine and automobile industries. Aluminium is extensively used in ships, aircrafts, cars, electrical wires and household utensils because it is abundant in nature. In the present study, Aluminium alloy Al6061 Hybrid Composites reinforced with Boron carbide and Coconut shell ash are fabricated to replace the individual Aluminium alloy Al6061. For that various tests to determine properties such as strength, hardness, wear and corrosion resistance are conducted on composite samples which make them fit to be used in aircraft window frames by reviewing various literatures. In addition to above, machinability analysis is performed on all the specimens and their surface roughness is measured. Based on the results obtained, we can come to a conclusion that the aluminium composite has superior properties than individual Al6061 alloy.


Author(s):  
T. Ramachandran ◽  
S. Sudhakara Reddy ◽  
S. Jeyakumar

Vibrations are found to be dangerous and reduce the life and reliability of the vehicle. The studies were carried out by many researchers to stiff the structures by increasing the wall thickness of the plates, rubber and to minimize the vibration by increasing the damping coefficient of the rubber materials. The conventional materials indicate an improvement in stiffness, but not satisfying the requirements of the engine vibration at different speed and load standards and also increased the mass of the structure. This research on the engine mount vibration isolation aims at developing an alternative material for the structures which exhibit good damping and stiffness characteristics. In terms of properties such as chemical resistance, ease of production, high strength to weight ratio and damping, composite materials are increasingly used in many engineering application where the vibration is predominant. In this paper, the steel plates are replaced by Al6061-SiC Metal Matrix Composites (MMC) and studies are carried out on the engine mount made of Al6061 MMC structural material and integrated with rubber. The static and dynamic properties of the Al6061MMC-rubber mounts are determined using experimental investigations. The harmonic analysis is also carried out to test the damping characteristics of the mounts.


2015 ◽  
Vol 813-814 ◽  
pp. 195-202 ◽  
Author(s):  
T. Lokesh ◽  
U.S. Mallikarjun

Abstract. In recent years, Aluminium alloy based metal matrix composites (MMC) are gaining wide spread acceptance in several aerospace and automobile applications. These composites possess excellent wear resistance in addition to other superior mechanical properties such as strength, modulus and hardness when compared with conventional alloys. The hybrid composites are new generation of composites containing more than one type, shape or sizes of reinforcements giving superior combined properties of reinforcements and the matrix. In the present work, Al6061 has been used as matrix material and the reinforcing materials selected were SiC and Graphite particulates of 10 to 30µm size. Composites Al6061-Gr (2- 8 wt. %), Al6061-SiC (2 -10wt. %) and Hybrid composites with Al6061 matrix alloy containing 3wt% graphite and varying composition of 2-10wt% SiCp were prepared by stir casting technique. The cast matrix alloy and its composites have been subjected to solutionizing treatment at a temperature of 530 ± 20C for 6 hours, followed by ageing at a temperature of 175 ± 20C for 6 hours. The mechanical properties of as cast and T6 heat treated composites have been evaluated as per ASTM standards and compared. Addition of Graphite particulates into the Al6061 matrix improved the strength and ductility of the composites. Significant improvement in tensile strength and hardness was noticed as the wt. % of SiCp increases in Al6061-SiC composites. Addition of Graphite into Al6061-SiC further improved the strength and ductility of hybrid composites. The heat treatment process had the profound effect in improving the mechanical properties of the studied composites. The microstructural studies revealed the uniform distribution of SiC and Gr particles in the matrix system.


2018 ◽  
Vol 183 ◽  
pp. 02001 ◽  
Author(s):  
Sandra Veličković ◽  
Slavica Miladinović ◽  
Blaža Stojanović ◽  
Ružica Nikolić ◽  
Branislav Hadzima ◽  
...  

Metal matrix composites (MMCs) are considered as important engineering materials due to their excellent mechanical, as well as tribological properties. When the metal (or alloy) matrix is reinforced with two or more reinforcements, those composites are the so-called hybrid composites. The aluminum metal matrix composites, reinforced with silicon carbide (SiC) and graphite (Gr), are extensively used due to their high strength and wear resistance. The tribological characteristics of such materials are superior to characteristics of the matrix. This research is presenting influence of the load and the graphite and silicon carbide contents the composites’ wear rate and the friction coefficient.


1995 ◽  
Vol 62 (1) ◽  
pp. 87-97 ◽  
Author(s):  
A. ten Busschen ◽  
A. P. S. Selvadurai

Micromechanical modeling is an important aspect in the study of fiber-reinforced composites. In such studies, an important class of structural parameters is formed by the interaction between the matrix and the embedded fibers. These interactive processes can be investigated by an appeal to a test which involves the segmentation of an embedded fiber. This test is referred to as a “fragmentation test.” During a fragmentation test, two distinct fracture phenomena are observed. These phenomena are directly related to the integrity of bond between the embedded fiber and the matrix. The first phenomenon involves situations where the interface bond is weaker than the matrix material. In this case the fiber fragment ends will slip and in this region shear stresses are transmitted by friction and/or interlocking mechanical actions. In contrast, when the interface bond has stronger properties than the matrix material, cracking will occur in the matrix region. Here, a crack initiated in the fiber will propagate into the matrix region typically forming conoidal cracks, or combinations of conoidal and flat cracks. This paper describes the background of the fragmentation test and the associated experimental research. Attention is focused on the experimental evaluation of matrix fracture topographies encountered in the fragmentation test.


1982 ◽  
Vol 55 (4) ◽  
pp. 1078-1094 ◽  
Author(s):  
J. L. Turner ◽  
J. L. Ford

Abstract Cord-rubber composite systems allow a visualization of interply shear strain effects because of the compliant nature of the matrix material. A technique termed the pin test was developed to aid this visualization of interply shear strain. The pin test performed on both flat pads and radial tires shows that interlaminar shear strain behavior in both types of specimens is similar, most of the shear strain being confined to a region approximately 10 interly rubber thicknesses from the edge. The observed shear strain is approximately an order of magnitude greater than the applied extensional strain. A simplified mathematical model, called the Kelsey strip, for describing such behavior for a two-ply (±θ) cord-rubber strip has been formulated and demonstrated to be qualitatively correct. Furthermore, this model is capable of predicting trends in both compliant and rigid matrix composites and allows for simplified idealizations. A finite-element code for dealing with such interply effects in a simple but efficient manner predicts qualitatively correct results.


2017 ◽  
Vol 25 (3) ◽  
pp. 209-214 ◽  
Author(s):  
G. Venkatachalam ◽  
A. Kumaravel

This paper presents the characterization of A356 composite reinforced with fly ash and basalt ash produced by stir casting method. Aluminium metal matrix composites (AMC) are used in wide variety of applications such as structural, aerospace, marine, automotive etc. Stir casting is cost effective manufacturing process and it is useful to enhance the attractive properties of AMCs. Three sets of hybrid AMC are prepared by varying the weight fraction of the reinforcements (3% basalt + 7% fly ash, 5% basalt + 5% fly, 7% basalt + 3% fly ash). The effect of reinforcements on the mechanical properties of the hybrid composites such as hardness, tensile, compressive and impact strength were studied. The obtained results reveal that tensile, compressive and impact strength was increased when weight fraction of fly ash increased, whereas the hardness increases when weight fraction of the basalt ash increased. Microscopic study reveals the dispersion of the reinforcements in the matrix.


2019 ◽  
Vol 817 ◽  
pp. 528-535 ◽  
Author(s):  
Tommaso D'Antino ◽  
Francesca Giulia Carozzi ◽  
Carlo Poggi

The use of inorganic matrix composites to strengthen and retrofit existing masonry and concrete structures has been gaining increasing interest in the last years. Among them, composite reinforced mortar (CRM) systems are a promising solution to increase the shear and flexural capacity of masonry panels. CRMs are comprised of a relatively thin inorganic matrix layer reinforced with a bi-dimensional grid made with high-strength fibers impregnated with an organic matrix. They are compatible with the substrate due to the use of inorganic matrix, have good durability and high-strength-to weight ratio due to the use of reinforcing composite materials. CRM systems are still in their infancy and limited research is available in the literature. In this paper, masonry walls constructed with historical bricks typical of the north of Italy were strengthened with a CRM system including a glass composite grid and a lime-based mortar and were subjected to diagonal compression. Three walls were strengthened with the CRM and one was used as a control specimen. The results obtained showed that the CRM system significantly increased the shear strength of the masonry panels subjected to diagonal compression.


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