Topic
Thermal expansion
About: Thermal expansion is a research topic. Over the lifetime, 21040 publications have been published within this topic receiving 349407 citations. The topic is also known as: heat expansion.
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TL;DR: In this paper, a photoelectric high speed acquisition system was used to generate nonsynchronous change of temperature rise and thermal expansion in thin films and the transient process of thermal expansion was recorded by a photo-electric high-speed acquisition system.
Abstract: Transient laser pulse has been used to generate nonsynchronous change of temperature rise and thermal expansion in thin films. The transient process of thermal expansion is recorded by a photoelectric high‐speed acquisition system. By comparison of the calculated temperature rise and thermal expansion, thermal stress relaxation processes in Al films of 20–50 μm thickness is obtained. This result shows that, for transient heating, thermal stress exists even in the case of uniform temperature distribution and free expansion. And also there is a transient high stress in thin films under high‐speed heating.
76 citations
TL;DR: In this article, the evolution of microstructure and coefficient of thermal expansion (CTE) of the Al-50Si alloy manufactured by spray deposition followed by hot isostatic pressing (HIP) are systematically investigated.
76 citations
01 Jul 2008
TL;DR: In this article, the authors present a systematic analysis of the mechanical Q-factor at low temperatures between 5 and 300 K on bulk silicon (100) samples which are boron doped.
Abstract: Future gravitational wave detectors will be limited by different kinds of noise. Thermal noise from the coatings and the substrate material will be a serious noise contribution within the detection band of these detectors. Cooling and the use of a high mechanical Q-factor material as a substrate material will reduce the thermal noise contribution from the substrates. Silicon is one of the most interesting materials for a third generation cryogenic detector. Due to the fact that the coefficient of thermal expansion vanishes at 18 and 125 K the thermoelastic contribution to the thermal noise will disappear. We present a systematic analysis of the mechanical Q-factor at low temperatures between 5 and 300 K on bulk silicon (100) samples which are boron doped. The thickness of the cylindrical samples is varied between 6, 12, 24, and 75mm with a constant diameter of 3 inches. For the 75mm substrate a comparison between the (100) and the (111) orientation is presented. In order to obtain the mechanical Q-factor a ring-down measurement is performed. Thus, the substrate is excited to resonant vibrations by means of an electrostatic driving plate and the subsequent ring-down is recorded using a Michelson-like interferometer. The substrate itself is suspended as a pendulum by means of a tungsten wire loop. All measurements are carried out in a special cryostat which provides a temperature stability of better than 0.1K between 5 and 300K during the experiment. The influence of the suspension on the measurements is experimentally investigated and discussed. At 5.8K a highest Q-factor of 4.5 ? 108 was achieved for the 14.9 kHz mode of a silicon (100) substrate with a diameter of 3 inches and a thickness of 12 mm.
76 citations
76 citations
TL;DR: In this article, the effects of preparing conditions such as sintering temperature (760 −790 ǫ°C), Sintering time (10 −40 min), Na2CO3 content (0 −3 wt%) and B2O3 content on the micromorphology have been systematically investigated by scanning electron microscopy, and the pore structure plays an important role in determining the apparent density, compressive strength, thermal conductivity, and thermal expansion coefficient.
76 citations