Ordering process and age-hardening mechanism of CuPd-AuCu pseudo-binary alloys were examined In alloys with electron-atom ratios (e/a)<0.87, short range ordering was observed in the early stage of aging, thereafter, long range ordering occurred from grain boundaries by heterogeneous ordering mecha nism. Age-hardening of these alloys was attained by the increase in volume fractions of CuPd and/o...

Shot peening is a process in which a stream of shot is blasted against an engineering component to generate a high compressive residual stress regime at the surface of the component. This paper describes a 3D finite element dynamic analysis of single shot impacting on a metallic component. The model is first validated against a published numerical study. A parametric study is conducted to inves...

When a strongly textured hexagonal close packed (HCP) metal is loaded under an orientation causing profuse twinning or detwinning, the stress-strain curve is sigmoidal in shape and inflects at some threshold. Authors have largely attributed the dramatic stress increase in the lower-bound vicinity of the inflection point to a combined effect of a Hall-Petch mechanism correlated to grain refineme...

The influence of rheological and surface properties on adhesive tackiness are studied. In particular, the importance of the elongational properties is emphasized in a model, which considers only the adhesive contribution, while neglecting the importance of cavitation and surface roughness. It is shown that this simple analysis allows one to recover the different types of curves (i.e. different ...

We use a modified filament stretching rheometer to quantify the influence of a known controlled pre-shear history on the transient extensional viscosity of a dilute polymer solution. Two different types of pre-deformation are explored; both influence the subsequent stretching significantly, albeit in opposite ways. Small-amplitude oscillatory straining parallel to the direction of stretching en...

A series of medium-carbon low alloy steels was quenched to martensite and tempered at 150 C. This low-temperature-tempered (LTT) martensite was subjected to uniaxial tensile and impact testing. Yield and ultimate tensile strength and uniform elongation increased, and post uniform and total elongation and fracture toughness decreased, with increasing carbon concentration. The carbon dependence o...

Asymptotic near-tip fields are analyzed for a plane strain Mode I crack propagating dynamically in non-associative elastic–plastic solids of the Drucker–Prager type with an isotropic linear strain hardening response. Eigen solutions are obtained over a range of material parameters and crack speeds, based on the assumption that asymptotic solutions are variable-separable and fully continuous. A ...

A fully modularized framework was established to combine isotropic, kinematic, and cross hardening behaviors under non-monotonic loading conditions. Three sets of state variables were defined and applied to consider the effects of, a) loading history, b) twinning and de-twinning and c) different pre-strain. Experiments under two types of nonproportional loading conditions were conducted along d...

experiments were carried out in which the dependence of the fractional softening on temperature, time and strain rate was determined in a 304h stainless steel. three prestrain ranges were identified pertaining to three different post-deformation softening behaviors: 1) prestraining to below the drx critical strain: strongly strain dependent softening by srx alone with softening kinetics control...