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.

Sputter target/backing plate assembly and method of making same

Abstract: A method of forming a sputter target/backing plate assembly comprises the steps of: providing a target fabricated from a first material having a coefficient of thermal expansion; providing a backing plate fabricated from a second material having a coefficient of thermal expansion; providing a block fabricated from a third material having a coefficient of thermal expansion; positioning the block on one side of the backing plate; positioning the target on the other side of the backing plate; and subjecting the target, backing plate and block to elevated temperature and pressure to bond the target, backing plate and block together. The third material is selected so as to have a coefficient of thermal expansion which counteracts the effects of the coefficients of thermal expansion of the first and second materials. The third material may be selected so as to have a coefficient of thermal expansion which is approximately the same as the coefficient of thermal expansion of the first material.

Slow dynamics near glass transitions in thin polymer films.

Abstract: The alpha process (segmental motion) of thin polystyrene films supported on glass substrate has been investigated in a wider frequency range from 10(-3) Hz to 10(4) Hz using dielectric relaxation spectroscopy and thermal expansion spectroscopy The relaxation rate of the alpha process increases with decreasing film thickness at a given temperature above the glass transition This increase in the relaxation rate with decreasing film thickness is much more enhanced near the glass transition temperature The glass transition temperature determined as the temperature at which the relaxation time of the alpha process becomes a macroscopic time scale shows a distinct molecular weight dependence It is also found that the Vogel temperature has a thickness dependence, ie, the Vogel temperature decreases with decreasing film thickness The expansion coefficient of the free volume alpha(f) is extracted from the temperature dependence of the relaxation time within the free volume theory The fragility index m is also evaluated as a function of thickness Both alpha(f) and m are found to decrease with decreasing film thickness

In-Plane Thermal Expansion and Thermal Bending Coefficients of Fabric Composites:

Abstract: This paper examines the in-plane thermal expansion coefficients and thermal bend ing coefficients of fabric composites. Three physical models have been adopted. The "mosaic model" provides a simple means for estimating these thermal properties. The one-dimensional "fiber undulation model" and the two-dimensional "bridging model" are suitable in particular for analyzing the thermomechanical behavior of plain weave and satin weave composites, respectively. The experimental results on in-plane thermal expansion coefficients of a 5-harness satin composite agree well with the theory.