The electronic structures and chemical bonding of selected ternary compounds of the family of A4T7X6 (of U4Re7Si6 –type) intermetallics have been studied by ab initio methods. The calculations for two series: Mg4Rh7P6, Sc4Co7Ge6, Ti4Co7Ge6 and uranium containing U4Re7Si6, U4Ru7Ge6, and U4Ru7As6 show common bonding characteristics pertaining to main T1-X and T2-X interaction (T = transition meta...

The influence of the addition of organic compounds, such as palmitic acid and cholesteryl myristate, on the porous structure of Fe-Al intermetallics formation has been investigated in detail in this paper. It was found that additives have a significant effect on the final porosity of the obtained sinters. Formed gaseous products from combustion play the role of the foaming agent during Fe-Al in...

A new method is proposed for estimating the enthalpies of formation of L12 (fcc-ordered) intermetallics from the heat release measured during ordering of their disordered polymorphs. The method is applied to Cu3Au, Ni3Al, and Ni3Si. The resulting estimates of enthalpies of formation are close to values obtained by high temperature dissolution calorimetry. They also appear to be more precise tha...

The development of Al-Si alloy and its based material for engine application is reported in this paper, focusing on improving the material’s fatigue limit and wear resistance, which are two important properties for engine block materials. The paper begins with a description of the microstructure (primary and eutectic phases, intermetallics, and casting defects) of Al-Si alloy and its effects on...

Highly oriented [111] Cu grains with densely packed nanotwins have been fabricated by direct-current electroplating with a high stirring rate. The [111]-oriented and nanotwinned Cu (nt-Cu) allow for the unidirectional growth of Cu(6)Sn(5) intermetallics in the microbumps of three-dimensional integrated-circuit packaging; a uniform microstructure in a large number of microbumps of controlled ori...

The present study investigates the mechanical behavior of severely plastic-deformed Cu-Al composite wires with different diameters and heat-treatments. Each holds 61 restacked copper-clad aluminum wires. bimetal composites were cold-worked up to ranging from 1 mm 3 mm, without any intermediate heat treatment. All contain hexagonal fibers a continuous copper network extended outer surface into c...

The main drawback of friction stir welding (FSW) dissimilar metals is the formation intermetallic compounds (IMCs), which are brittle and affect strength joint. these inevitable due to their low enthalpy formation; however, emergence an indication metallurgical bonding between metals. This means that determining factors intermetallics should be optimal ensure joint and, at same time, performanc...