Directionally solidified (DS) Ni-base superalloys have become a commonly used material in gas turbine components. Controlled solidification during the material manufacturing process leads to a special alignment of the grain boundaries within the material. This alignment results in different material properties dependent on the orientation of the material. When used in gas turbine applications t...

Low cycle fatigue–creep is the main reason for the failures of many engineering components under high temperature and cyclic loading. Based on the exhaustion of the static toughness and dissipation of the plastic strain energy during fatigue failure, a new low cycle fatigue–creep life prediction model that is consistent with the fatigue–creep damage mechanism and sensitive to the fatigue damage...

The stress-strain relationship in shales is generally time-dependent. This concerns their long-term deformation unconventional reservoirs, and its influence on the situ stress state therein. paper presents an experimental investigation time-dependent of Longmaxi shale gas shale. A series creep experiments subject samples to long-term, multi-step triaxial compression. It found that exhibit varyi...

Superior creep strength of a heat resistant AX52 magnesium alloy is ascribed to the grain boundary eutectic Al2Ca phase covering the primary -Mg grains. The eutectic phase is stable in morphology at temperatures below 473K, while it collapses during long term exposure at temperatures higher than 473K. The microstructural change of the alloy during high temperature exposure is characterized by t...

Long term tensile creep studies were conducted on binary NiAl in the temperature range 700-1200 K with the objectives of characterizing and understanding the creep mechanisms. Inverse and normal primary creep curves were observed depending on stress and temperature. It is concluded that the primary creep of NiAl is limited by dislocation mobility. The stress exponent for creep, n, decreased fro...

abstract: a time domain semi-analytical solution to study thermoelastic creep behavior of  functionally graded rotating axisymmetric disks with variable thickness is presented. the rate type governing differential equations for the considered structure are derived and analytically solved. to solve these  equations, the disk is divided into some virtual sub-domains. general solution of  equilibr...

A study was conducted to characterize the microstructure of electron beam welds in high purity niobium and its effect on creep behaviour at room temperature. The parent material was 2mm sheet with a 50 μm grain size. The weld fusion zone had ~ 1mm grains, implying that these grains all intersected the free surface. The parent material showed no room temperature creep deformation below the yield...

Objectives: Nanocrystalline (nc) metals present excellent mechanical properties such as strength and fatigue resistance but often show low ductility. Furthermore, nc systems show moderate to high rate sensitivity at room temperature which might help restoring the ductility but can have disadvantage of creep/relaxation effects in applications. Thin metallic films constitute ideal candidates for ...