Coefficient of thermal expansion as a component quality estimation of alloys on pistons of combustion engines

The aim of realized works in the area of materials on pistons is: low thermal expansion, small differences of coefficient of thermal expansion between heating and cooling, high stiffness at elevated temperatures, high hardness and wear resistance. Changes in thermal expansion coefficient during heating and cooling may be very large, as well as during subsequent cycles of heating and cooling of an internal combustion engine pis ton with respect to standard silumin alloys usedfor pistons of internal combustion engines. The paper presents: coefficient of linear expansion a for the AlSi standard alloy, coefficient of linear expansion a for the AlSi alloy with the apositive differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the a negative differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the apositive and negative differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the apositive, negative and positive differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the very small a differences between cooling and heating, coefficient relative elongation as afunction of temperature with the positive elongation differences between cooling and heating, coefficient relative elongation with the very small elongation differences between cooling and heating, coefficient the course of derivative as a function of temperature (T) during heating and cooling with the positive elongation differences.