P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences we...

In order to improve the corrosion resistance of aluminosilicate refractories by molten aluminum, alkaline fluoride NaF and cryolite Na3AlF6 powders were studied. Both physical and chemical properties are known to influence wetting and corrosion behavior. This paper devoted to determine the influence of alkaline fluoride and cryolite added to andalusite based castable on the reaction with a...

High strength aluminum alloys, especially those containing zirconium, are historically difficult to grain refine. Early efforts by Alcoa indicated that the addition of lithium to these alloys increases difficulty with grain refinement. Although grain refining of alloys 2090 and 2091 was possible, consistent results were not obtained. Statistically-designed experiments were used to quickly ident...

Raney catalysts were prepared by a combination of mechanical alloying and leaching as an alternative in the synthesis of Raney-Nickel catalysts. Binary Al-Ni and ternary Al-Ni-Fe alloys with nominal compositions Al65Ni35, Al75Ni25, Al65Ni30Fe5, Al75Ni20Fe5 (in atomic percent), were processed from pure elemental powders; they consisted mainly of the intermetallic B2 AlNi phase. Aluminum was sele...

Hypereutectic aluminum silicon alloys are mainly used in cast form in important components like pistons, cylinder liners, rocker arms, air conditioner compressors, brake drums, engine blocks, etc. These have inherent advantages of being high wear resistance, high strength to weight ratio, high corrosion resistance, good cast performance, high thermal conductivity, good weldability, etc. The inf...

This lecture aims at providing a survey of the metallographic techniques available for the examination of aluminium and its alloys. The information must be sufficient to be sure that the students and the users are able to choose the most suitable technique to solve their problems in the examination of samples. The lecture should contain a direct understanding of the main problems in the metallo...

For last several decades aluminium and aluminium alloys are widely used in automotive industries because for their favourable properties like low density (about 2700 Kg/m 3 ), good malleability, high formability, high corrosion resistance and high electrical and thermal conductivity. High machinability and workability of aluminium alloys are prone to porosity due to gases dissolved during melti...

Aluminum alloys containing Sc are promising materials for high-temperature structural applications due to the high strengthening effect of the Al3Sc (L12 structure) precipitates [1]. Further improvements in strength and nanostructural stability of Al-Sc based alloys are achieved by adding alloying elements, such as Mg, as solid-solution strengtheners. It is important to understand the effects o...