Indentation creep tests and finite element simulations were performed on a model material to show that the constitutive equation for conventional uniaxial creep can be derived using the instrumented indentation testing technique. When the indentation pressure and the indentation creep rate are maintained at constant values of ps and _ 3⁄4inðsÞ, respectively, the contours of the equivalent stres...

Indentation creep tests were performed on an Al-5.3mol% Mg solid-solution alloy to examine whether mechanical properties can be extracted accurately from a testpiece, as small as a rice grain. A conical diamond indenter was pressed into a test surface with a constant load F at temperatures ranging from 0.60 to 0.65 Tm (Tm: the absolute liquidus temperature). When the representative flow stress ...

It is crucial to understand the creep behavior of Pb-free solder alloys in electronic packaging. Typical service environments are between 298 and 373K. The thermal mismatch induced stresses acting on solder joints result in extensive rate-dependent plastic deformation. The solder alloy is potentially the weakest component in the electronic package because normal operating temperatures are alrea...

With flexible leaded parts, the solder-joint failure process involves a complex interplay of creep and fatigue mechanisms. To better understand the role of creep in typical multi-hour cyclic loading conditions, a specialized non-linear finite-element creep simulation computer program has been formulated. The numerical algorithm includes the complete part-lead-solder-P WB system, accounting for ...

Tensile and creep properties of new austenitic steel Sanicro 25 at room temperature and operating temperature 700 °C were investigated by testing on miniature specimens. The results were correlated with testing on conventional specimens. Very good agreement of results was obtained, namely in yield and ultimate strength, as well as short-term creep properties. Although the creep rupture time was...

Efficient numerical finite-element analysis of creeping concrete structures requires the use of Kelvin or Maxwell chain models, which are most conveniently identified from a continuous retardation or relaxation spectrum, the spectrum in turn being determined from the given compliance or relaxation function. The method of doing that within the context of solidification theory for creep with agin...

steady state creep of the alloy was in a thermodynamical steady state, (2) which configuration of the dislocation network was contributing to the creep strength, and (3) which change in the dislocation network was the cause of the creep recovery. Specimens were furnace-cooled under stress and then observed by transmission electron microscopy. The creep stress was reduced during the test and the...