In the current investigation, AA2024 aluminum alloy is reinforced by alumina nanoparticles using a friction stir process (FSP) with multiple passes. The mechanical properties and microstructure observation are conducted experimentally using tensile, microhardness, and microscopy analysis methods. The impacts of the process parameters on the output responses, such as mechanical properties and microstructure grain refinement, were investigated. The effect of multiple FSP passes on the grain refinement, and various mechanical properties are evaluated, then the results are conducted to train a hybrid artificial intelligence predictive model. The model consists of a multilayer perceptrons optimized by a grey wolf optimizer to predict mechanical and microstructural properties of friction stir processed aluminum alloy reinforced by alumina nanoparticles. The inputs of the model were rotational speed, linear processing speed, and number of passes; while the outputs were grain size, aspect ratio, microhardness, and ultimate tensile strength. The prediction accuracy of the developed hybrid model was compared with that of standalone multilayer perceptrons model using different error measures. The developed hybrid model shows a higher accuracy compared with the standalone model.
The uniaxial compressive strength is an important parameter in selecting and design of rock and brittles structure. Protection of ancient monuments or historic structure has a great intense in material science point of view. Limestone is commonly rock material which has a great sense in historical buildings and temples. The strength of this material may be influenced by natural weathering like moisture, rains and varying temperature. Samples of ancient limestone rock are coated with Paraloid B44, Paraloid B72, ethyl silicate and Wacker OH100. The results concluded that both Wacker OH100 and Paraloid B44 coating material have more efficient and give considerable protection when the sample is immersed in salinity water for a week. The compressive strength of limestone decreases due to water action. Water absorption, porosity, and rock density are enhanced with the coating process.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.