Two Ti2AlNb intermetallic orthorhombic (O) alloys, Ti-15Al-33Nb and Ti-21Al29Nb(at.%), were subtransus processed into sheets, using pancake forging and hot-pack rolling, and evaluated in tension (25 and 650°C) and creep (650-710°C) and the properties and deformation behavior were related to microstructure. Some of the microstructural features evaluated were grain boundary character, grain size,...

Diffusion-controlled-creep processes are used to assess the creep behavior of dispersion and solute hardened materials at coarse and fine grain sizes. It is shown that the creep behavior of a dispersion strengthened (DS) Al–Mg alloy is similar to the creep behavior of pure Al–Mg alloys. Both materials show dislocation climb and dislocation solute-drag contributions to creep. It is shown that th...

A high temperature measurement system for creep deformation based on the digital image correlation (DIC) technique is described. The new system is applied to study the behaviour of a multi-pass welded joint in a high temperature tensile test and a load controlled creep test at 545°C. Spatially resolved tensile properties and time dependent creep deformation properties across a thick section typ...

This paper presents a review of creep deformation and rupture mechanism of P91 alloy for the development of its creep damage constitutive equations under lower stress level. Creep damage is one of the serious problems for the high temperature industries and computational approach (such as continuum damage mechanics) has been developed and used, complementary to the experimental approach, to ass...

This paper summarizes and presents research progress on the fundamentals of the development of creep damage constitutive equations for high Cr steels including 1) a brief summary of the characteristics of creep deformation and creep damage evolution and their dependence on the stress level and the importance of cavitation for the final fracture; 2) a critical review of the state of art of creep...

Introduction: Simple models of geomorphic modification of planetary surfaces by erosion or deposition are reported here. These processes are linear and non-linear creep, uniform accrescence and decrescence, and non-linear airfall deposition. They do not include models of flow whose depth is of the same order of magnitude as the landform, such as glacial flow or relaxation of crater forms in pla...

This paper presents a review of creep deformation and rupture mechanisms of low Cr-Mo alloy for the development of its creep damage constitutive equations under lower stress. The most popular Kachanov-Robatnov-Hayhurst (KRH) formulation was not necessarily developed and calibrated for low stress and cannot depict the creep strain accurately under multi-axial state of stress due to the three-dim...

Both clays and calcium silicate hydrates(the main hydration products of Portland cements) exhibit a microstructure made up of lamellar particles. The microscopic mechanism responsible for the macroscopic creep of such materials is often described as the relative sliding of the sheets. This paper proposes a micromechanical approach to estimate the macroscopic creep behavior rising from this micr...

The creep and wear behaviour of highly cross-linked polyethylene and standard polyethylene liners were examined in a prospective, double-blind randomised, controlled trial using radiostereometric analysis. We randomised 54 patients to receive hip replacements with either highly cross-linked polyethylene or standard liners and determined the three-dimensional penetration of the liners over three...

Recent studies concerning the fixation of cemented total hip arthroplasty (THA) have led to new hypotheses about the dynamic, long-term failure mechanisms leading to prosthetic loosening. As a result, the long-term mechanical behavior of acrylic bone cement has gained more interest since little is known about these properties. In this study, the dynamic, compressive creep deformation of acrylic...