A Comparative Study of Mechanical Properties,Thermal Conductivity,Residual Stresses,and Wear Resistance of Aluminum-Alumina Composites Obtained by Squeeze Casting and Powder Metallurgy

Squeeze casting and powder metallurgy techniques were employed to fabricate AlSi12/Al₂O₃ composites, which are lightweight structural materials with potential applications in the automotive industry. The impact of the processing route on the material properties was studied. Comparative analyses were conducted for the Vickers hardness, flexural strength, fracture toughness, thermal conductivity, thermal residual stresses, and frictional wear. Our results show that the squeeze cast composite exhibits superior properties to those obtained using powder metallurgy.

     

Correction to: A Comparative Study of Mechanical Properties,Thermal Conductivity,Residual Stresses,and Wear Resistance of Aluminum-Alumina Composites Obtained by Squeeze Casting and Powder Metallurgy

Metallurgical and Materials Transactions A -     

Experimental Determination of the Length-Scale Parameter for the Phase-Field Modeling of Macroscale Fracture in Cr–Al2O3 Composites Fabricated by Powder Metallurgy

Metallurgical and Materials Transactions A - A novel approach is proposed to determine a physically meaningful length-scale parameter for the phase-field modeling of macroscale fracture in...     

Mechanical properties of twisted filaments

The knowledge of some mechanical properties of twisted filament is necessary to predict properties of continuous-filament yarns. Retraction, strength, strain, and elastic properties of filaments are the chief characteristics. Assuming that the filament can be considered as a yarn made of fibers bounded together and then twisted, formulas for prediction of those properties were elaborated and then compared with the experimentally received values. Satisfactory agreement of computed results with experimental values is obtained if the changes in volume of filament at strain is taken into account.     

LASER RAMAN SPECTROSCOPY OF PRECIPITATES: APPLICATIONS IN CATALYSIS

Precipitates are important precursors in the preparation of catalysts, pigments, fillers, and other metal oxides and sulfides. Despite the extensive investigations of these colloidal systems, the mechanism of precipitate formation and particle growth remains unclear. The processes involved during precipitation are complex and are sensitive to many environmental factors. The solutions of the metal salts used in the precipitation also may be complex, particularly for mutli-valent ions. Precipitate solutions are extremely difficult to characterize in situ with most spectroscopic techniques. The use of Raman spectroscopy is highly advantageous since precipitates may be examined in aqueous solution without interference from the presence of water.

A series of bismuth molybdate selective oxidation catalysts were characterized during preparation using in situ Raman spectroscopy. Spectra were recorded during the precipitation and aging of stoichiometric γ-Bi₂MoO₆ and Bi₂Mo₃O₁₂ catalysts. The formation of these phases was related to the slate of aggregation of molybdenum and bismuth species. Various techniques were used to obtain the Raman spectra of the precipitates, which are briefly described.     

Experimental and Numerical Investigation of the Deformation and Fracture Mode of Microcantilever Beams Made of Cr(Re)/Al2O3 Metal–Matrix Composite

Metallurgical and Materials Transactions A - This work presents a combined experimental and computational study of the deformation and fracture of microcantilever specimens made of...