Petru Moldovan

New Quaternary Type of Al-Sr-Ti-B Master Alloy for Grain Refining and Modifying of Al-Si

The paper’s aim is to present the processing of a new master alloy similar to STROBLOY. This alloy represents a combination of two master alloys, already known in aluminum industry (AlTiB and AlSr). The benefits of this new alloy are the cut of Ti, B and Sr consumption, as well as a grain refining/modification ecological technology for Al-Si and Al-Mg-Si alloys. So, this alloy was obtained from binary AlB8, AlSr10 and AlTi10 master alloys melted in an electric resistance furnace and argon atmosphere. Samples were cast in an iron mould. As STROBLOY, this new quaternary alloy contains fast dissolving SrAl4 particles important in modification stage, and nucleating particles such as TiB2 and (Al, Ti)B2 essential for grain refining of aluminum alloys.

The Combined Effect of Modifier and Grain Refiner AlTiBSr Master Alloy on Microstructure and Porosity of Aluminum Alloys

The aim of the paper is to present the influence of a new multifunctional material, a master alloy named Al-Sr-Ti-B, in aluminum foundry alloys. The Al-Sr-Ti-B master alloy represents a new combination of two master alloys, already known in aluminum industry, AlTiB and AlSr, used in treatment of aluminum alloys for grain refining and modification. As Strobloy, our master alloy contain fast dissolving SrAl4 particles and also nucleating particles as TiB2 and (Al,Ti)B2 which are important first in modification and second in grain refining of aluminum alloys. The paper presents optic and electron microscopy studies realized on AlSi7Mg alloy treated with this new multifunctional material

Powder Metallurgy Processing of Al/TiAl3+Al2O3

This paper aims to present a way of obtaining aluminum based composite material obtained by powder metallurgy technique. We start mixing and milling the powders, compressing and sintering the samples. We established a sintering cycle for this type of composite material and studied obtained samples by SEM microscopy. The reaction between the matrix and the precursor of the reinforcing materials was studied with the aid of HSC 4.0 program, available at Engineering and Management of Metallic Materials department.

The Effect of Grain Refiners for Aluminium Alloy Containing Mn-Ti-Sr Dispersoid

The new structural applications of aluminum materials are determined by intelligent lightweight design: the demand of safety, ecology, recycling and by economics. Al-Si alloys allow complex shapes to be cast. Metallurgical a high volume fraction of fine dispersoid which are less about 0.1 microns in size are useful for retaining a fine grain. In the 6061 series of alloys, iron combines with aluminium and silicon to form two types of commune inter-metallic, (beta AlFeSi and alpha AlFeSi).The type of inter-metallic that is present these alloys will have an important bearing on the homogenization time, workability and quality of the surface finish. The microstructure of the as-cast samples was evaluated by electronic microscopy and the morphology of inter-metallic compounds related to the efficiently modification. Mn-Ti-Sr modification of Al-alloys is normally accompanied by an increase in porosity in the casting.