Prediction of fracture toughness temperature dependance from tensile test parameters

As a heat treatable aluminum alloy to be used in T6 and T8 temper, belongs to Al-Cu-Li system, a novel high-strength aluminum-lithium alloy 2A97 was developed. In order to improve the relationships of strength and ductility and fracture toughness, and to urge the applications in the aeronautical and aerospace industries, the effects of normal heat treatments and thermomechanical heat treatments on the mechanical properties and fracture toughness were investigated by Transmission Electron Microscope(TEM), Scanning Electronic Microscope (SEM), tensile test, and fracture toughness test. The results show that for the alloy aged at 135 °C for 24 h after quenching and 4 percent plastic deformation, its microstructures are strengthened by strain hardening and precipitation hardening, consisting of fine T1phase, θ″/θ′ phase and δ′ phase densely and homogeneously distributed in the matrix. It yields optimum relationship of strength and ductility, fracture toughness, its σ0.2, σband δ5are 454 MPa, 536 MPa, and 11.8%, respectively. It yields 43.5 MPa·m1/2of Kqvalues higher than that of 42.5 MPa·m1/2 in T6 temper. The fracture morphologies of impact tensile samples of fracture toughness test and normal tensile test were observed, indicating the dominance of intergranular failure and subintergranular failure with some dimples and trangranular failure.

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Tensile Properties of Polymer Repair Materials - Effect of Test Parameters

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1129.445 ◽

2015 ◽

Vol 1129 ◽

pp. 445-452

Author(s):

Z. Kamil ◽

G. Andrzej ◽

C. Sandra ◽

A.J. Barroso

Keyword(s):

Tensile Strength ◽

Tensile Test ◽

Modulus Of Elasticity ◽

Deformation Rate ◽

Effect Of Temperature ◽

Uniaxial Tensile ◽

Uniaxial Tensile Test ◽

Sample Shape ◽

Repair Materials ◽

Test Parameters

In this research, five types of polymer repair materials were selected for investigation of the influence of sample shape, deformation rate and test temperature on the mechanical properties determined with an uniaxial tensile test. The results showed the clear effect of measurement conditions on tensile strength, elongation and modulus of elasticity. The highest tensile strength and modulus of elasticity were exhibited by epoxy resin for the filling of concrete cracks, which achieved 1% elongation. The lowest coefficient of dispersion characterized the results of tensile test carried out using dumbbell samples at a deformation rate of 50 mm/min. The effect of temperature varied with the material type.

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Comparative Study on Morphological, Physical and Mechanical Characteristics of L-PBF Based Alsi10mg Parts with Conventional Stir Casted Al-10%Sic Composites

10.21203/rs.3.rs-246358/v1 ◽

2021 ◽

Author(s):

M. Saravana Kumar ◽

E. Mohan ◽

S. Robinson ◽

D. ThivyaPrasad

Keyword(s):

Fracture Toughness ◽

Shear Stress ◽

Tensile Test ◽

Stress Test ◽

Morphological Characteristics ◽

Hardness Test ◽

Stir Casting ◽

Fracture Toughness Test ◽

Double Shear ◽

Toughness Test

Abstract Stir casting plays a major role in production of Al-SiC10% composites for aero space and automobile applications. However, obtaining the composites with homogenous distribution of the SiC particles, low porosity and without clustering of reinforcement particles were still a major problem faced by the research community. These kinds of casting defects were overcome by the Additive Manufacturing (AM) technology. In this research, AlSi10Mg parts were manufactured by Laser-Powder Bed Fusion (LPBF) method, one of the AM techniques. The mechanical and morphological characteristics of AM samples were compared with the Stir Casted (SC) samples. The influence of print orientation on the mechanical properties was also evaluated. It was found that the AM samples printed along the XY directions shows 26.5% and 8.2%higher fracture toughness and shear strength than AM samples printed along the Z directions. Both AM and SC samples were analyzed for the porosity% using the Optical Microscope (OM). The result shows that the AM sample shows reduced porosity of 1.4%. Mechanical testing such as tensile test, hardness test, fracture toughness test and double shear stress were carried out. The results obtained from the tensile test AM samples show 14.6% higher tensile strength than the SC samples, from the hardness test AM samples show 18.6% higher hardness strength than the SC samples, from the fracture toughness test AM samples show 33.4% higher fracture toughness strength than the SC samples and from the double shear stress test prove that the AM samples show 24.6% higher shear stress than the SC samples. The outcome of this research, it was proved that additive manufactured AlSi10Mgsample shows enhanced mechanical and morphological properties when compared with the conventional stir casting process.

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Dynamic and Static Fracture Toughness of Al/Epoxy Resin Interface

Volume 12: Advanced Materials: Design, Processing, Characterization, and Applications ◽

10.1115/imece2019-11081 ◽

2019 ◽

Author(s):

Yusaku Saito ◽

Kosuke Sudo ◽

Kohei Kanamori ◽

Akio Yonezu

Keyword(s):

Fracture Toughness ◽

Stress Distribution ◽

Tensile Test ◽

Epoxy Resin ◽

Laser Irradiation ◽

Interfacial Fracture ◽

Initial Crack ◽

Al Alloy ◽

Interfacial Fracture Toughness ◽

Static Fracture

Abstract This study evaluates the interfacial fracture strength and toughness of an epoxy resin/aluminum alloy based on two different tests of impact loading and quasi-static loading. In the impact test, we carried out the Laser Shock Adhesion Test (LaSAT). This method uses a strong ultrasonic wave induced by pulsed laser irradiation to induce interfacial fracture. Due to the grease layer ablation caused by laser irradiation, strong elastic wave generates and propagates. The tensile stress acts on the Al/epoxy resin interface, inducing an interfacial delamination. This delamination is further extended by an additional laser irradiation in order to evaluate the interfacial fracture toughness. By simulating the experimental delamination progression in FEM (Finite Element Method), we evaluated the dynamic fracture toughness of the Al alloy/epoxy resin interface. On the other hand, a quasi-static test for the toughness evaluation was conducted using a uniaxial tensile test. Before the tensile test, we produced an initial crack (initial delamination) at the interface by using laser ablation. Subsequently, this sample having initial crack is loaded by uniaxial tension. It is found that the interfacial crack progresses, resulting in unstable interfacial fracture. Furthermore, we conducted FEM simulation, in order to estimate the stress distribution near the delamination. By deriving a stress intensity factor from the stress distribution, we evaluated the quasi-static fracture toughness. To compare the dynamic and quasi-static fracture toughness of Al alloy/epoxy resin interface, we clarified the loading rate dependency of interfacial fracture toughness.

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