Kinetics of gray cast iron strengthening at room and elevated temperature (100°C, 182°C and 285°C) were studied using 100 specimens cast from one industrial heat of gray iron. Tensile strength and Brinell hardness was measured during age strengthening. Peak aging was observed at shorter times for higher temperatures and over-aging was observed at 182°C and 285°C. Statistically significant data ...

At temperatures moderately below their glass transition temperature, the properties of many glass-forming materials can evolve slowly with time in a process known as physical aging whereby the thermodynamic, mechanical, and dynamic properties all drift towards their equilibrium values. In this work, we study the evolution of the thermodynamic and dynamic properties during physical aging for a m...

dual phase steels with different martensite volume fraction and morphology were tensile tested at a temperature range of 25 to 5500c. stress-strain curves of all steels showed serration flow at temperatures of 250 and 3500c, and smooth flow at the other temperatures. both yield and ultimate tensile strengths increased with increasing testing temperature up to about 4500c and then decreased at h...

The internal structure of a molecule can be presented in terms of intra-molecular (i.e., inter atomic)and inter-molecular energies such as van der Waals, bond and bending, torsion, and inversion energy.In this study, changes in molecular energies of individual asphalt components are evaluated as afunction of physical aging factors. The factors for physical aging such as temperature and pressure...

The progressive application of non-linear loads in distribution systems (DS) increases current harmonics flow in DS's apparatuses, especially distribution transformers (DTs). Since DTs' operating temperature rises due to the harmonics flow, their loading should be reduced such that the hot spot temperature (HST) is preserved under its permissible value. This means that DTs' available capacity i...

Bias Temperature Instability (BTI) and Hot Carrier Injection (HCI) are two major causes for transistor aging at nano-scale, leading to slower devices, more failures during runtime, and ultimately reduced lifetime. Typically these issues are handled by adding extra guardbands to the design, i. e. overdesign, which results in lower clock frequencies and hence, performance losses. Alternatively, e...

In order to evaluate the reliability of using repulped cellulose in transformers, the aging process was applied on standard and repulped cellulose in a laboratory accelerated model by increasing of temperature to 150 ° C and their behavior was monitored by measuring the amount of 2-furfural released in oil by HPLC (High Performance Liquid Chromatography) in the consecutive aging periods and...

as we know sol-gel is one of the most important techniques for thin film preparation. in this paper, high transmission silica thin films have been prepared by dip-coating process from a new silicon-alkoxide solution. the prepared sol was stable for 45 days which is very important to characterize the coating process. the optical properties as a function of aging time, withdrawal rate, and heat t...

In order to reveal the nature of Ultraviolet aging(UV-aging) behavior asphalt molecules, dynamic microstructure during ultraviolet aging was simulated by Materials Studio software. The effect UV on transformation, aggregation and motion state is analyzed changes in energy, microstructural morphological variation, glass transition temperature viscosity molecular system. results show that Satruat...

2011 Transistor aging effects in Nano-scale CMOS result in transistor performance degradation over the device lifetime. The primary physical mechanism behind transistor aging is Bias Temperature Instability (BTI). Such transistor aging results in circuit performance degradation over time. In this research we are interested in analyzing the impact of the BTI aging effect on clock skew in on-chip...