ÐTransformation superplasticity of an intermetallic Ti3Al-based alloy (Super a2) is demonstrated by thermal cycling about the a2/b transformation temperature range under a uniaxial tensile biasing stress. Failure strains up to 610% were recorded at a stress of 3 MPa, compared with 110% for deformation by isothermal creep at the same stress. The strain increment produced during each half-cycle i...

Pr0.5Ca0.5Mn1−xCrxO3 (x= 0.015-0.05) undergoes an insulator-metal (I-M) transition below a temperature Tp driven by percolation of ferromagnetic metallic clusters in a charge ordered insulating matrix. Surprisingly, the I-M transition in these compounds is unstable against thermal cycling : Tp decreases and the resistivity at Tp increases upon temperature cycling between a starting temperature ...

Sn-Ag-Cu (SAC) alloy is currently recognized as the standard lead-free solder alloy for packaging of interconnects in the electronics industry, and highAg-content SAC alloys are the most popular choice. However, this choice has been encumbered by the fragility of the solder joints that has been observed in drop testing as well as the high cost of the Ag itself. Therefore, low-Ag-content SAC all...

OBJECTIVES To evaluate the color stability and hardness of two denture liners obtained by direct and indirect techniques, after thermal cycling and immersion in beverages that can cause staining of teeth. MATERIAL AND METHODS Seventy disc-shaped specimens (18 x 3 mm) processed by direct (DT) and indirect techniques (IT) were made from Elite soft (n=35) and Kooliner (n=35) denture liners. For ...

This study evaluated the bond strength of veneering porcelain with an experimental conditioner-coated zirconia. Pre-sintered Y-TZP specimens (n = 44) were divided in two groups based on conditioning type. After sintering, all sample surfaces were sandblasted and layered with veneering porcelain. Additionally, half of the specimens in each group underwent thermal cycling (10,000 cycles, 5-55 °C)...

A roadblock to the development of stand-alone microscale biomedical and chemical analysis systems is the relatively high heating power requirement of the microscale reactors, which typically exceeds the capability of low cost batteries. In this study, a microchannel thermal cycling reactor design using in-channel heating and passive cooling is proposed and a numerical model has been developed. ...

the effects of closely adapting a prefabricated fiber to the post space remain unknown. the purpose of this study was to quantify the microleakages of a custom adapted fiber-reinforced post, a prefabricated quartz fiber post and a cast post using nondestructive methods.sixty-five extracted human premolars were endodontically treated and randomly divided into three groups (n=15), which were rest...

Computational modeling of reaction systems can provide a strong foundation for experimental investigations. In this investigation, we first propose a unique theoretical system for breaking chiral symmetry that utilizes thermal cycling to amplify a small initial asymmetry. Unlike models in the literature, no autocatalytic reactions were needed for homochirality in this model to emerge. Following...

The thermal cycling reliability of candidate copper and aluminium power substrates has been assessed for use at temperatures exceeding 300°C peak using a combination of thermal cycling, nanoindentation and finite element modelling to understand the relative stresses and evolution of the mechanical properties. The results include the relative cycling lifetimes up to 350°C, demonstrating almost a...