Tribological and Mechanical Properties of Hybrid nHAp/ SiO2/chitosan Composites Fabricated from Snail Shell Using Grey Rational Grade (GRG) Analysis

Silicon ◽  
2021 ◽  
Author(s):  
Gangadharan T. ◽  
Kailasanathan C. ◽  
Rajkumar P. R ◽  
Perumal. A. ◽  
Chitra Priya Darshini K.R
2016 ◽  
Vol 718 ◽  
pp. 40-44
Author(s):  
Sujirat Tepsila ◽  
Amnart Suksri

Silicone rubber room temperature vulcanization (RTV) is widely used as an insulator. This paper aims to improve the electrical and mechanical properties of RTV with organic filler from golden apple snail shells. The processed golden apple snail shells have the particle size of 75 μm. Specimen were made from silicone rubber with an addition of organic filler and inorganic filler for tested under ASTM D638-2a standard. The filler ratio was varying from 0 to 50% by weight with incremental of 5%. Experimental results showed that, there were good agreement in threshold of electrical and mechanical properties. RTV with the organic filler ratio of 40% out performed the inorganic filler in electrical aspect. Tensile strength of RTV was found to be increased when 5% addition of organic filler is used and decreases steadily as this filler is increased. The amount of filler has greater contribution to the hardness property of the RTV and it may become brittle when it is used in excessive amount.


2020 ◽  
pp. 163-180
Author(s):  
M.Y. Kolawole ◽  
J.O. Aweda ◽  
S. Abdulkareem ◽  
S.A. Bello ◽  
A. Ali ◽  
...  

Nowadays, low-cost particulate reinforced metal matrix composites with improve mechanical properties are highly sought in various industrial and critical engineering applications including automotive and aerospace sectors. Meanwhile, increasing consumption rate of African giant land snail (Archachatina marginata) had been posing disposal challenges of its shells. Therefore, this paper tends to investigates the influence of waste snail shells particulates on the physical and mechanical properties of recycled aluminum- silicon alloy matrix. Different weight proportions i.e. (0 - 7.5) wt% of calcined snail shell particles at an interval of 1.5 wt% were successfully incorporated into Al-Si alloy matrix melted at 750 ?C using stir-casting route. The microstructure, physical and mechanical properties of the resulting composites were examined and presented. Microstructural examination shows fairly uniform dispersion of snail shell particles in the aluminium alloy matrix intermingled with aluminium-silicon dendrites. Mechanical properties such as hardness, impact, compressive and tensile strengths increased with increasing addition of calcined snail shell particulate up to 6 wt% while density and elongation decreases. The total equivalent density reduction of 5.4% in composites compared to unreinforced alloy was obtained at 7.5 wt% snail shell addition. The maximum hardness, impact, compressive and tensile strengths obtained are 118?4 HV, 88 J, 552?20 MPa and 211 ? 4.8 MPa equivalent to 21, 25, 19 and 36 percent increase respectively relative to un-reinforced aluminium-silicon alloy. Hence, mechanical and physical properties of Al-Si alloy can be enhanced using calcined snail shell particulates which can widen its application in automotive industries.


Silicon ◽  
2021 ◽  
Author(s):  
T. Gangadharan ◽  
C. Kailasanathan ◽  
P. R. Rajkumar ◽  
A. Perumal ◽  
K. R. Chitra Priya Darshini

Author(s):  
S. Fujishiro

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.


Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).


Author(s):  
D. R. Clarke ◽  
G. Thomas

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.


Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.


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