Directionally-solidified (DS) Ni-base superalloys are commonly applied as turbine materials to primarily withstand creep conditions manifested in either marine-, airor landbased gas turbines components. The thrust for increased efficiency of these systems, however, translates into the need for these materials to exhibit considerable strength and temperature resistance. Accurate prediction of cr...

2014 The analysis of creep transitories after a change in oxygen partial pressure, allowed us to determine chemical diffusion coefficients for CoO and Cu2O, singleand polycrystals. The rate of equilibration of point defect concentrations is similar for all defects. Grain boundaries do not seem to accelerate the process. Tome 21 ? 6 JUIN 1986 Revue Phys. Appl. 21 (1986) 343-348 JUIN 1986,

in this paper the effects of non-linearity of suspension on dynamic behavior of a railway wheelset has been studied. this wheelset has four degrees of freedom that with two constraints it has reduced to two degrees of freedom. vermeulen-johnson theory has been used to calculate contact forces between wheel and rail. in this study the creep coefficients have considered constant. any linearizatio...

Background: The short-time creep behavior for a series of biodegradable nanocomposites which is used as implantable device into body is a crucial factor. In the current paper, we aimed to study the effect of bioactive glass nanoparticles (BGn) on creep and creep-recovery behaviors of PLA/PCL blends at different given load and different applied temperatures. Method: A series of biodegradab...

In the Present study, attempt will be made to propose a new method for prediction of long-term essential creep of concrete utilizing some short-term creep tests under high temperature. To do so, regarding the similarities between essential creep of concrete and creep in viscoelastic materials, the time–temperature equivalence relation in viscoelastic materials is evaluated for concrete. This re...

creep phenomenon in rock engineering plays a key role in development of underground spaces as they must be stable enough for a long period of time. current research involved designing and manufacturing of a new creep testing machine. the equipment is capable to perform simultaneous light-duty creep tests on more than one cylindrical rock samples at a very low cost.to evaluate the equipment’s pe...

mechanism and factors influencing on creep behavior of clay soil have not been understood yet due to its complex structure. in this paper, to investigate the affecting parameters on the creep behavior of the clay soils such as stress level, over consolidated pressure and water pressure, odeometr test are performed in states of single stage, stepwise and overloaded-unloaded and the creep mechani...

materials exhibit significant creep behavior at temperatures above 40% of their absolute melt temperature. lead, tin and their alloys are such materials which experience significant creep behavior in room temperature. one of the most important applications of the tin-lead alloys is soldering electronic circuits in electronic industry, and for lead are isolation walls and wet batteries. room tem...

Commercial zirconium carbide (ZrC) powder is consolidated by Spark Plasma Sintering (SPS). Processing temperatures range from 1650 to 2100 °C. Specimens with various density levels are obtained when performing single-die SPS at different temperatures. Besides the single-die tooling setup, a double-die tooling setup is employed to largely increase the actual applied pressure to achieve higher de...

Time-dependent creep stress redistribution analysis of thick-walled FGM spheres subjected to an internal pressure and a uniform temperature field is investigated. The material creep and mechanical properties through the radial graded direction are assumed to obey the simple power-law variation throughout the thickness. Total strains are assumed to be the sum of elastic, thermal and creep strain...