Carbon/Carbon Composites: Fabrication and Properties and Selected Experiences

1988 ◽  
Vol 125 ◽  
Author(s):  
Richard C. Dickinson

ABSTRACTCarbon/Carbon is a highly desirable material for use at elevated temperatures in structural applications due to its high strength-to-weight ratio and increasing strength with increasing temperatures.This presentation will survey the general methods used to fabricate and apply oxidation protection systems to these composites. This will be followed by an overview of typical physical and mechanical properties and selected results from oxidation rate studies.

Author(s):  
Ben Young ◽  
Hai-Ting Li

High strength steels are becoming increasingly attractive for structural and architectural applications due to their superior strength-to-weight ratio which could lead to lighter and elegant structures. The stiffness and strength of high strength steels may reduce after exposure to fire. The post-fire mechanical properties of high strength steels have a crucial role in evaluating the residual strengths of these materials. This paper presents an experimental investigation on post-fire mechanical properties of cold-formed high strength steels. A series of tensile coupon tests has been carried out. The coupon specimens were extracted from cold-formed square hollow sections with nominal yield stresses of 700 and 900 MPa at ambient temperature. The specimens were exposed to various elevated temperatures ranged from 200 to 1000 °C and then cooled down to ambient temperature before tested to failure. Stress-strain curves were obtained and the mechanical properties, namely, Young’s modulus, yield stress (0.2% proof stress) and ultimate strength, of the cold-formed high strength steel materials after exposure to elevated temperatures were derived. The post-fire retention factors that obtained from the experimental investigation were compared with existing predictive equations in the literature. New predictive equations are proposed to determine the residual mechanical properties of high strength steels after exposure to fire. It is shown that the proposed predictive equations are suitable for both cold-formed and hot-rolled high strength steel materials with nominal yield stresses ranged from 690 to 960 MPa.


2016 ◽  
Vol 16 ◽  
pp. 1-6 ◽  
Author(s):  
S. Nallusamy

Over the past two decades it has been established that composite materials are the leading emerging materials. The natural fibres present a number of advantages over traditional synthetic fibres because of their better corrosion resistance, excellent thermo-mechanical properties and high strength to weight ratio. Also the composite materials play an important role in maintaining the eco-friendly design requirements. Among this, polymer matrix composite is one of the recent developing sectors on the composite field, because it has high strength with less density as compared to the metal matrix composite. Depending on the applications, the properties of the polymer reinforced composite are improved by modifying compositions, process of fabrication and direction of fibre etc. In this analysis the Roselle Fibre (Hibiscus Sabdariffa) is reinforced with polymer composite by wt % in the mode of compression molding. The mechanical properties of the above fabricated material were analyzed by ASTM Standards and also the characterization of polymer composites were analysed using SEM. The compressive strength and the hardness value were high as compared to other strength properties; hence it is more suitable for compressive and structural applications. The results concluded that the treated fibre with chemical reveals better compatibility with polymer matrix than that of untreated fibre.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2600
Author(s):  
Milad Bazli ◽  
Milad Abolfazli

Fibre-reinforced polymer (FRP) composite is one of the most applicable materials used in civil infrastructures, as it has been proven advantageous in terms of high strength and stiffness to weight ratio and anti-corrosion. The performance of FRP under elevated temperatures has gained significant attention among academia and industry. A comprehensive review on experimental and numerical studies investigating the mechanical performance of FRP composites subjected to elevated temperatures, ranging from ambient to fire condition, is presented in this paper. Over 100 research papers on the mechanical properties of FRP materials including tensile, compressive, flexural and shear strengths and moduli are reviewed. Although they report dispersed data, several interesting conclusions can be drawn from these studies. In general, exposure to elevated temperatures near and above the resin glass transition temperature, Tg, has detrimental effects on the mechanical characteristics of FRP materials. On the other hand, elevated temperatures below Tg can cause low levels of degradation. Discussions are made on degradation mechanisms of different FRP members. This review outlines recommendations for future works. The behaviour of FRP composites under elevated temperatures provides a comprehensive understanding based on the database presented. In addition, a foundation for determining predictive models for FRP materials exposed to elevated temperatures could be laid using the finding that this review presents.


2011 ◽  
Vol 471-472 ◽  
pp. 85-90 ◽  
Author(s):  
Maryam Sobhani ◽  
Abolghasem Khazaeian ◽  
Taghi Tabarsa ◽  
Alireza Shakeri

The purpose of this study was to determine some physical and mechanical properties of sandwich panels manufactured from the core of Paulownia wood and surfaces of multilayer of fiberglass and resins. Paulownia was selected among Hardwoods because of its s low density (0.26 g/cm3) and high strength/weight ratio. Eight treatments were used for experiments: Two kinds of fiberglass (needle and combination of the needle and curtain type), two various resins (polyester and epoxy) and two core thicknesses (9mm and 19mm). Physical properties including density, resistance to water absorption, Dimensional stability, and Mechanical Properties such as internal bonding, compressive and bending strength of panels were measured following ASTM Standard. The results indicated that panels with 19 mm thick core had lower density (0.5g/ cm3) compared to the 9mm thick panels (0.7g/cm3). Bigger volume of wood in the core of panels with higher thickness was the main reason of this result. The experimental results showed that thickness of wood was effective on the modulus of rupture, modulus of elasticity, and compressive strength, significantly. Epoxy resin presented higher internal bond compared to the polyester resin. The two kind of fiberglass (needle one and the combination of needle and curtain type) didn’t have noticeable differences on mechanical properties. It also was found that Paulownia is a promising species for manufacturing sandwich panel.


2016 ◽  
Vol 716 ◽  
pp. 973-980
Author(s):  
Enrico Simonetto ◽  
Giulia Venturato ◽  
Stefania Bruschi ◽  
Andrea Ghiotti

Titanium and titanium alloys are largely used in aircrafts to manufacture piping and structural components, thanks to the high strength-to-weight ratio and the excellent corrosion resistance. However, despite the advantages in terms of mechanical and chemical performances, they present significant limits when shaped at room temperature due to the high strength and the low ductility. The use of temperature-assisted processes might represent an interesting option to overcome the above-mentioned limitations, although the effects on the microstructural and chemical properties should be accurately considered.The paper presents the results of investigations on the Ti3Al2.5V alloy, carried out to evaluate the influence that the thermal cycle parameters have on the mechanical properties and microstructural characteristics of tubes draw bent at elevated temperatures. Tensile tests at elevated temperatures have been performed on specimens directly cut from tubes in order to get the flow-stress curves and elastic material properties. With reference to typical industrial process conditions, different heating rates and soaking times were tested to analyse the influence on the microstructure, namely the grain size, the precipitation of secondary phases and superficial oxidation. Scanning Electron Microscopy and micro-hardness measurement techniques were used to assess the post-forming characteristics at different temperature and strain rate conditions.


2018 ◽  
Vol 13 (s1) ◽  
pp. 127-134
Author(s):  
Hyginus E. Opara ◽  
Uchechi G. Eziefula ◽  
Bennett I. Eziefula

Abstract This study compared the physical and mechanical properties of river sand concrete with quarry dust concrete. The constituent materials were batched by weight. The water-cement ratio and mix ratio selected for the experimental investigation were 0.55 and 1:2:4, respectively. The specimens were cured for 7, 14, 21 and 28 days. Slump, density and compressive strength tests were carried out. The results showed that river sand concrete had greater density and compressive strength than quarry dust concrete for all curing ages. At 28 days of curing, river sand concrete exceeded the target compressive strength by 36%, whereas quarry dust concrete was less than the target compressive strength by 12%. Both river sand concrete and quarry dust concrete for the selected water/cement ratio and mix ratio are suitable for non-structural applications and lightly-loaded members where high strength is not a prerequisite.


Alloy Digest ◽  
1994 ◽  
Vol 43 (11) ◽  

Abstract CARLSON ALLOYS C600 AND C600 ESR have excellent mechanical properties from sub-zero to elevated temperatures with excellent resistance to oxidation at high temperatures. It is a solid-solution alloy that can be hardened only by cold working. High strength at temperature is combined with good workability. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: Ni-470. Producer or source: G.O. Carlson Inc.


Alloy Digest ◽  
1983 ◽  
Vol 32 (3) ◽  

Abstract BRUSH Alloy 3 offers the highest electrical and thermal conductivity of any beryllium-copper alloy. It possesses an excellent combination of moderate strength, good corrosion resistance and good resistance to moderately elevated temperatures. Because of its unique physical and mechanical properties, Brush Alloy 3 finds widespread use in welding applications (RWMA Class 3), current-carrying springs, switch and instrument parts and similar components. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-454. Producer or source: Brush Wellman Inc..


Alloy Digest ◽  
1986 ◽  
Vol 35 (7) ◽  

Abstract UNS No. A97075 is a wrought precipitation-hardenable aluminum alloy. It has excellent mechanical properties, workability and response to heat treatment and refrigeration. Its typical uses comprise aircraft structural parts and other highly stressed structural applications where very high strength and good resistance to corrosion are required. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on low temperature performance as well as forming, heat treating, and machining. Filing Code: Al-269. Producer or source: Various aluminum companies.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.


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