No abstract

The article is focused on the analysis changes dependence on the temperature on the aluminium alloy with 10,1% Mg, 1,32% Si and 0,43% Mn by internal friction. Internal friction is a property of the material is measured on the ultrasonic resonant aparature at a frequency about f = 20470 Hz. The measured temperature range was from 50 °C up to 420 °C. Precisely measurement of the internal friction can be monitored ongoing structural changes and various mechanisms that prevent these changes.

Internal damping is able to monitor the microstructural changes in solid materials and these changes can be based onvarious mechanisms. In this investigation a same heat treatment was carried out on AZ31 and AZ91 magnesium alloys, aimed at detection of microstructure changes of material after homogenization annealing and also the process of precipitation was continuously analyzed by the internal damping measurement. Internal damping was measured as a function of temperature in AZ31 and AZ91 magnesium alloys by ultrasonic resonance spectroscopy. The internal damping spectrum was measured in the temperature range from 50 °C up-to 390 °C. Peaks of internal damping occurred in temperature range from 250 °C up-to 350 °C on AZ91 magnesium alloy. Also the mictrostructure analysis was carried out at the diferent stages of the internal damping measurement which showed creation of continuous precipitate in the maximum of the internal damping peak. The creation of the peak is caused by absorbation of energy by the process of continuous precipate nucleation and growth in the volume of material grains.

The article is focused on the analysis of changes in the dependence on temperature on the aluminium alloy EN AC 51200 (10,1% Mg, 1,32% Si and 0,43% Mn) by internal friction. Internal friction is a property of the material measured on the ultrasonic resonant apparatus at a frequency of about f = 20470 Hz. The measured temperature range was from 50 °C up to 420 °C. The precise measurement of the internal friction can be monitored on an ongoing process by structural changes and various mechanisms that prevent these changes.

Internal friction is reflecting a conversion of mechanical energy to heat and causes attenuation of vibrations in the material. This article is aimed at the effect of precipitation hardening on the hardness of AZ 61 magnesium alloy. The changes of microstructure were mapped by internal friction with use of the ultrasonic resonance device. The goal was to find the relationship between the internal friction and microstructure of the experimental material.