An Investigation of the Effect of Cryo-Cooling on Natural Frequency and Wear Properties of Ageable Al Alloys

Abstract

In this study, the influence of the cryogenic cooling on the natural frequency and wear behaviors of the three different aluminum alloys of AA2024, AA6061 and AA7075 were examined. In addition, hardness and microstructural observations were also performed to reveal the effect of cryogenic cooling on the wear performance of the Al alloys. Pin on disc test equipment was utilized to observe the wear performance of the Al alloys and field emission scanning electron microscope was used to go in depth about microstructural evaluations. For the determination of the natural frequency of the Al alloys designed with different tapered angles from 0° to 1°, vibration test equipment was used. As a result of this work, it has been observed in experimental and analytical analysis that the natural frequency values decrease with the increase of the tapered angle of the fixed beam attached from the short (b) side. The highest frequency values were obtained when the tapered angle was 0º in the experimental and analytical analysis of the fixed beam attached from the short (b) side. Again, the highest frequency values were obtained when the tapered angle of the fixed beam, which was attached from the short (b) side, was 1º in the experimental and analytical analysis. In addition, when the worn surfaces and wear data are examined in general, it is seen that the amount of oxide on the surface increases as a result of the applied cryo-cooling, and because of the increased oxide layer, metal-to-metal contact occurs during wear, and it acts as a solid lubricant by protecting the surface under the metal. In this way, it has been observed that the wear loss is reduced and the worn surface images are directly affected. The results of the analytical and experimental analyses of fixed-support beams indicate that the natural frequency values of the beam can be altered by modifying the tapered angle of the beam and the location of the support. Lastly, no significant change was observed in natural frequency values with cryogenic effect.