scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Effects of temperature and strain rate on compressive flow behavior of aluminum-boron carbide composites

01 May 2014-Journal of Composite Materials (SAGE Publications)-Vol. 48, Iss: 11, pp 1313-1321
TL;DR: In this article, the authors investigated the flow properties of aluminum and aluminum-boron carbide (Al-B4C) composites, containing 5, 10 and 15 wt% B4C, at compression tests at strain rates of 10−4, 10−3 and 10−2 s−1 over the temperature range 25 to 500℃.
Abstract: Flow properties of aluminum and aluminum-boron carbide (Al-B4C) composites, containing 5, 10 and 15 wt% B4C, were investigated by compression tests at strain rates of 10−4, 10−3 and 10−2 s−1 over the temperature range 25 to 500℃. The nature of stress–strain curves as a function of reinforcement, temperature and strain rate revealed that (1) flow stress initially increases as the reinforcement increases, but it decreases for Al-15% B4C composite, (2) flow stress increases with the increase in strain rate, with the strain rate sensitivity index varying from 0.01 for aluminum at 200℃ to 0.30 for Al-5% B4C composite. The activation energy for deformation is found to vary from 124 to 187 kJ/mol for Al-15% B4C and Al-5% B4C composites, respectively.
Citations
More filters
Journal ArticleDOI
TL;DR: Microstructure evolution of 15'wt% boron carbide particle reinforced aluminum matrix composites (B4C/Al composites) with titanium addition during liquid-stirring process was dynamically characteriz...
Abstract: Microstructure evolution of 15 wt% boron carbide particle reinforced aluminum matrix composites (B4C/Al composites) with titanium addition during liquid-stirring process was dynamically characteriz...

32 citations

Journal ArticleDOI
TL;DR: In this article, the deformation behavior of a rolled Al-15vol% B4C composite was studied at high temperatures, using single tensile tests over a wide range of strain rates.
Abstract: Deformation behavior of a rolled Al-15 vol% B4C composite was studied at high temperatures, using single- tensile tests over a wide range of strain rates. The deformation of the composite is characterized by high apparent stress exponent, na and high activation energy, Qa, which are higher than those reported in pure Al. The analysis showed the presence of threshold stress that its value increases with decreasing the testing temperature. Using the threshold stress in the analysis, the obtained values of the true stress exponents, nt of ~ 5 and the true activation energy, Qt of 130 kJ mol−1, were similar to those reported for pure Al. TEM results of subgrain formation along with the mechanical data (nt and Qt) suggest that dislocation climb in the Al matrix is the rate controlling mechanism. The elongation (ef %) showed a maximum value at 500 °C at intermediate value of Zener-Hollomon parameter, Z. The fracture surfaces of tested samples are characterized by mixed modes of ductile (dimple formation) and brittle (cleavage) failures, which were dependent on the deformation conditions of temperature and strain rate.

15 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the tensile flow behavior of aluminum-boron carbide (Al-B4C) composites of 0, 5 and 15% B4C, hot rolled to ~88% with intermediate annealing at 350°C, and found that the strain rate sensitivity index (m) was found to be ~0.1 over for all the composites in both as-cast as well as hot rolled condition.
Abstract: High temperature tensile flow behavior of aluminum-boron carbide (Al-B4C) composites of 0, 5 and 15% B4C, hot rolled to ~88% with intermediate annealing at 350 °C, was investigated by constant initial strain rate (CIS) test technique at 500 °C and strain rate jump test technique over the temperature range of 400–500 °C. In the as-cast condition, the flow stresses obtained between CIS and strain rate jump test techniques were found to be significantly different at 500 °C. The strain rate sensitivity index (m) was found to be ~0.1 over for all the composites in both as-cast as well as hot rolled condition. Tensile elongations were found to be 0.36 in both as-cast and hot rolled aluminum, whereas the same reduced in Al-5% B4C composite to 0.35 and 0.27, respectively. The values of activation energy (Q) for deformation of rolled aluminum and Al-5% B4C composite were determined to be 194.2 and 73.4 kJ/mol, respectively. The microstructural examination, using SEM and EBSD techniques, revealed cavitation in alum...

4 citations

References
More filters
Book
01 Jan 1993
TL;DR: In this article, the Eshelby approach is used to model composites and a program for calculating the S-tensors of a composite model is presented, along with a list of programs for an Eshelbys calculation.
Abstract: Preface 1. General introduction 2. Basic composite models 3. The Eshelby approach to modelling composites 4. Plastic deformation 5. Thermal effects and high temperature behaviour 6. The interfacial region 7. Fracture processes and failure mechanisms 8. Transport properties and environmental performance 9. Fabrication processes 10. Development of matrix microstructure 11. Testing and characterisation techniques 12. Applications Appendix 1. Nomenclature Appendix 2. Matrices and reinforcements - selected thermophysical properties Appendix 3. The basic Eshelby S-tensors Appendix 4. Listing of a program for an Eshelby calculation.

1,826 citations

Book
01 Jan 1976

1,743 citations


"Effects of temperature and strain r..." refers background in this paper

  • ...Aluminum (Al) is an attractive material due to its low density, high corrosion resistance, high ductility, high thermal and electrical conductivities.(1,2) However, it has poor strength, which can be improved by either precipitation or dispersion hardening, but at the expense of ductility....

    [...]

Book
22 Dec 2003
TL;DR: In this paper, the second-rank tensors of a tensor were modeled as tensors and they were used to model the deformation of polycrystalline materials and their properties.
Abstract: Chapter 1. Introduction.1.1 Strain1.2 Stress.1.3 Mechanical Testing.1.4 Mechanical Responses to Deformation.1.5 How Bonding Influences Mechanical Properties.1.6 Further Reading and References.1.7 Problems.Chapter 2. Tensors and Elasticity.2.1 What Is a Tensor?2.2 Transformation of Tensors.2.3 The Second Rank Tensors of Strain and Stress.2.4 Directional Properties.2.5 Elasticity.2.6 Effective Properties of Materials: Oriented Polycrystals and Composites.2.7 Matrix Methods for Elasticity Tensors.2.8 Appendix: The Stereographic Projection.2.9 References.2.10 Problems.Chapter 3. Plasticity.3.1 Continuum Models for Shear Deformation of Isotropic Ductile Materials.3.2 Shear Deformation of Crystalline Materials.3.3 Necking and Instability.3.4 Shear Deformation of Non Crystalline materials.3.5 Dilatant Deformation of Materials.3.6 Appendix: Independent Slip Systems.3.7 References.3.8 Problems.Chapter 4. Dislocations in Crystals.4.1 Dislocation Theory.4.2 Specification of Dislocation Character.4.3 Dislocation Motion.4.4 Dislocation Content in Crystals and Polycrystals.4.5 Dislocations and Dislocation Motion in Specific Crystal Structures.4.6 References.4.7 Problems.Chapter 5. Strengthening Mechanisms.5.1 Constraint Based Strengthening.5.2 Strengthening Mechanisms in Crystalline Materials.5.3 Orientation Strengthening.5.4 References.5.5 Problems.Chapter 6. High Temperature and Rate Dependent Deformation.6.1 Creep.6.2 Extrapolation Approaches for Failure and Creep.6.3 Stress Relaxation.6.4 Creep and Relaxation Mechanisms in Crystalline Materials.6.5 References.6.6 Problems.Chapter 7. Fracture of Materials.7.1 Stress Distributions Near Crack Tips.7.2 Fracture Toughness Testing.7.3 Failure Probability and Weibull Statistics.7.4 Mechanisms for Toughness Enhancement of Brittle Materials.7.5 Appendix A: Derivation of the Stress Concentration at a Through Hole.7.6 Appendix B: Stress Volume Integral Approach for Weibull Statistics.7.7 References.7.8 Problems.Chapter 8. Mapping Strategies for Understanding Mechanical Properties.8.1 Deformation Mechanism Maps.8.2 Fracture Mechanism Maps.8.3 Mechanical Design Maps.8.4 References.8.5 Problems.Chapter 9. Degradation Processes: Fatigue and Wear.9.1 Cystic Fatigue of materials.9.2 Engineering Fatigue Analysis.9.3 Wear, Friction, and Lubrication.9.4 References.9.5 Problems.Chapter 10. Deformation Processing.10.1 Ideal Energy Approach for Modeling of a Forming Process.10.2 Inclusion of Friction and Die Geometry in Deformation Processes: Slab Analysis.10.3 Upper Bound Analysis.10.4 Slip Line Field Analysis.10.5 Formation of Aluminum Beverage Cans: Deep Drawing, Ironing, and Shaping.10.6 Forming and Rheology of Glasses and Polymers.10.7 Tape Casting of Ceramic Slurries.10.8 References.10.9 Problems.Index.

1,630 citations


"Effects of temperature and strain r..." refers background in this paper

  • ...In composites like the present one, the particles become additional source of enhancing dislocation density through the increasing geometrically necessary dislocations.(33) A comparison of stress–strain curves for composites containing different levels of B4C suggests that the work hardening rate is enhanced by addition of reinforcement but does not show any systematic dependence between the different levels of B4C reinforcement....

    [...]

Journal ArticleDOI
TL;DR: Boron carbide has high melting point, outstanding hardness, good mechanical properties, low specific weight, great resistance to chemical agents and high neutron absorption cross-section (10BxC, x>4) is currently used in high-technology industries as discussed by the authors.
Abstract: Boron carbide, which has a high melting point, outstanding hardness, good mechanical properties, low specific weight, great resistance to chemical agents and high neutron absorption cross-section (10BxC, x>4) is currently used in high-technology industries—fast-breeders, lightweight armors and high-temperature thermoelectric conversion. The contents of this review are: (1) introduction; (2) preparations—industrial preparative routes, powders, sintering (additives, pressureless, hot pressing, HIP); laboratory methods of synthesis (CVD, PVD, plasma, crystal growth); (3) analytical characterization; (4) phase diagram—a peritectic, nearly pure boron, and a wide phase homogeneity range (B4C-B10·5C); (5) rhombohedral crystal structure—a comprehensive model of the whole solid solution is proposed; (6) chemical properties; (7) physical properties—density, mechanical (strength, hardness, toughness) and thermo-electrical properties; (8) main industrial applications; (9) conclusion.

1,232 citations

Journal ArticleDOI
TL;DR: Aluminum matrix composites (AMCs) refer to the class of light-weight high performance aluminium centric material systems as mentioned in this paper, which can be tailored to the demands of different industrial applications by suitable combinations of matrix, reinforcement and processing route.
Abstract: Aluminium matrix composites (AMCs) refer to the class of light weight high performance aluminium centric material systems. The reinforcement in AMCs could be in the form of continuous/discontinuous fibres, whisker or particulates, in volume fractions ranging from a few percent to 70%. Properties of AMCs can be tailored to the demands of different industrial applications by suitable combinations of matrix, reinforcement and processing route. Presently several grades of AMCs are manufactured by different routes. Three decades of intensive research have provided a wealth of new scientific knowledge on the intrinsic and extrinsic effects of ceramic reinforcement vis-a-vis physical, mechanical, thermo-mechanical and tribological properties of AMCs. In the last few years, AMCs have been utilised in high-tech structural and functional applications including aerospace, defence, automotive, and thermal management areas, as well as in sports and recreation. It is interesting to note that research on particle-reinforced cast AMCs took root in India during the 70’s, attained industrial maturity in the developed world nd is currently in the process of joining the mainstream of materials. This paper presents an overview of AMC material ystems on aspects relating to processing, icrostructure, roperties and applications.

1,009 citations


"Effects of temperature and strain r..." refers background in this paper

  • ...Aluminum (Al) is an attractive material due to its low density, high corrosion resistance, high ductility, high thermal and electrical conductivities.(1,2) However, it has poor strength, which can be improved by either precipitation or dispersion hardening, but at the expense of ductility....

    [...]