Vibration influence on structure and density of aluminum alloys
The results of study on aluminum alloys of grade AK9M2 AK12M2 are provided. Alloy crystallization time for alloys AK9M2 AK12M2 decreases, the intensity of reduction depends on the vibration amplitude. For alloys AK9M2 and AK12M2 the optimal amplitude is 2^2.2 mm, allowing a dense cast alloy with a fine grain structure to be obtained. Density of samples from AK12M2, cut from the bottom part, is slightly increases with the rise of the vibration amplitude.
Abstract By using a five pass Fabry-Perot interferometer we have observed Brillouin scattering from longitudinal sound waves in films of amorphous silicon prepared by glow discharge decomposition of silane. Both the sound velocity and the scattering efficiency are found to depend on the hydrogen content of the film. For small hydrogen content the velocity is observed to be comparable with that of crystalline Si. The implications of our results for pure amorphous Si are different than for the results of Testardi and Hauser on sputtered samples.