The effect of microstructural variations on the fracture toughness of Alloy 718 was reviewed. The metallurgical parameters surveyed in this paper included heat treatment, heat-to-heat variations, product-form variations, neutron irradiation and long-term thermal aging. Key microstructural features and operative fracture mechanisms were related to macroscopic fracture toughness properties.

Nowadays, application of cermet coatings deposited by High-Velocity Oxygen-Fuel (HVOF) has received considerable attention in a variety of industries. Carbide coatings have high surface roughness, so it is essential to grind the coated surface. The present investigation studied the effect of simultaneous changes in the grinding parameters including the depth of cut, feed rate and cutting sp...

Fracture assessment of U- and V-notches is important in mechanical engineering. One can use the J-integral as fracture parameter in order to predict the critical fracture load in notches. The critical value of the J-integral in cracks is a function of the material properties. In notches, however, the material properties as well as the notch dimensions affect this critical value (named fracture ...

This paper presents a novel Membrane Deflection Fracture Experiment (MDFE) to investigate the fracture toughness of MEMS and other advanced materials in thin film form. It involves the stretching of freestanding thin-film membranes, in a fixed-fixed configuration, containing pre-existing cracks. The fracture behavior of ultrananocrystalline diamond (UNCD), a material developed at Argonne Nation...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. This article presents a novel microscratch technique for the determination of the fracture toughness of materials f...

The fracture toughness and uniaxial tensile yield strengths of unmodified and CTBN-rubbermodified epoxies were measured under hydrostatic pressure. The purpose of these experiments was to learn how suppressing cavitation in rubber particles affects the deformation mechanisms and the fracture toughness of rubber-modified epoxy. It was found that the cavitation of CTBN-rubber could be suppressed ...

Interlaminar fracture mechanics has proven useful for characterizing the onset of delaminations in composites and has been used with limited success primarily to investigate onset in fracture toughness specimens and laboratory size coupon type specimens. Future acceptance of the methodology by industry and certification authorities however, requires the successful demonstration of the methodolo...

Age-related deterioration of the fracture properties of bone, coupled with increased life expectancy, is responsible for increasing incidence of bone fracture in the elderly, and hence, an understanding of how its fracture properties degrade with age is essential. The present study describes ex vivo fracture experiments to quantitatively assess the effect of aging on the fracture toughness prop...