A new technique for measuring the elastic-plastic properties of porous thin films by means of nanoindentation is proposed. The effects of porosity on indentation hardness and modulus are investigated through finite element analyses based on the Gurson model for plastic deformation of ductile porous materials. Intrinsic mechanical properties of the thin film are obtained by eliminating both subs...

The problem: A new type of steel is known as Twining Induced Plasticity Steel, more commonly known as TWIP Steel. There is a general interest in using this type of steel in the automotive industry due to its unique material properties such as super toughness and super ductility, although its chemical properties also play a vital role. It has a high content of Mn (more than 25%) and about 3% Si ...

Nacre from seashells, also known as mother-of-pearl, has attracted much attention for its remarkable mechanical properties despite the structural weaknesses of its components [1],[2]. In this article, in situ-tensile tests of dry and wet nacre dogbone specimens are presented. Optical microscopy and digital image correlation techniques were used to determine deformation and strain fields . While...

The growth of a single cylindrical hole ahead of a blunt crack tip was studied using large deformation finite element analysis in three-point bend specimens with different precrack depth. The effect of small second phase particles was taken into account by incorporating Gurson’s constitutive equation. The effects of strain hardening and the initial distance from the hole to the crack tip were a...

Deformation and failure under multiaxial stresses-a survey of laboratory techniques and experimental-data-by-W, J. Evans National Gas Turbine Establishment SUMMARY A survey has been made of techniques for producing multiaxial stress conditions on a laboratory scale and it is concluded that one of the more suitable systems is combined tension-torsion of thin-walled tubes. Experimentally this tec...

This paper uses X-ray computed tomography to track the mechanical response of a vertebrate (Barnacle goose) long bone subjected to an axial compressive load, which is increased gradually until failure. A loading rig was mounted in an X-ray computed tomography system so that a time-lapse sequence of three-dimensional (3D) images of the bone's internal (cancellous or trabecular) structure could b...

Fe-Mn-C austenitic steels exhibit outstanding high-ductile deformation in their plastic regions along with significant microstructural evolution. In this study, to characterize the microstructural evolution during deformation of these steels, line-profile and texture analyses were carried out using X-ray diffraction. The convolutional multiple whole profile fitting procedure was used for a line...

Different from the homogenous deformation in conventional crystalline alloys, metallic glasses and other work-softening materials deform discontinuously by localized plastic strain in shear bands. Here by three-point bending test on a typical ductile Pd-Cu-Si metallic glass, we found that the plastic deformed region during fracture didn't follow the yielding stress distribution as the conventio...

This chapter presents numerical simulation work and single-point nano-machining experiments conducted on semiconductor and ceramic materials, e.g. silicon (Si) and silicon carbide (SiC). The apparent ductile mode material removal mechanism observed in these materials is believed to be the result of a high pressure phase transformation (HPPT), which generates a small Correspondence/Reprint reque...