to investigate the hot deformation behavior of 17-7 ph stainless steel, hot compression tests were carried out at the temperatures of 950, 1050 and 1150 oc and strain rates of 0.001 s-1 to 0.1 s-1. accordingly, the hot working behavior was studied by the analyses of flow stress curves, work hardening rate versus stress curves, exponent- type constitutive equations and deformed microstructures. ...

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...

Thermomechanical deformations of a body made of two different materials and undergoing simple shearing deformations are studied with the objectives of finding out when and where adiabatic shear bands will initiate and how they will subsequently grow. Each material is modeled as strain and strain-rate hardening but thermally softening. A shear band is presumed to have formed if the introduction ...

In mechanical tests of tantalum-tungsten alloys with nominal tungsten contents between 0 and 10 wt% for strain rates between 0.000016 and 6800 sr and temperatures between 77 and 400 K, the addition of tungsten noticeably reduces the strain-rate dependence of the flow stress of tantalum near yield. It also subtly alters the strain-rate behavior of the work hardening, making it more like that of ...

2014 Constant strain rate compressions along 001 > have been performed on CoO single crystals (03B5 ~ 6 x 10-5 s-1). Yield stresses and work hardening rates have been measured between 77 K and 1 400 K; CoO is very strong when compared to similar compounds. Vickers indentations have been performed on { 100 }, { 110 } and { 111 } faces around the Néel temperature, i.e. between 0 °C and 40 °C...

The toughness of a polymer glass is determined by the interplay of yielding, strain softening, and strain hardening. Molecular-dynamics simulations of a typical polymer glass, atactic polystyrene, under the influence of active deformation have been carried out to enlighten these processes. It is observed that the dominant interaction for the yield peak is of interchain nature and for the strain...

In a recent letter, Govaert et al. examined the relationship between strain hardening modulus Gr and flow stress σflow for five different glassy polymers. In each case, results forGr at different strain rates or different temperatures are linearly related to the flow stress. They noted that this linear relation is different than a simple proportionality between Gr and σflow, which they claimed ...

A rejuvenated Zr-based bulk metallic glass is tested in tension: it shows strain-hardening and reaches 0.9% plastic strain at failure. The initial rate of increase flow stress with 73 GPa, much higher than normal for polycrystalline metals alloys. This hardening its decay increasing are compared published data on a representative range conventional novel Taking the onset necking as failure, usi...