Sintering behaviour and mechanical properties of PM Al-Zn-Mg-Cu alloy containing elemental Mg additions

Abstract

Zn, and Si, which are all soluble in aluminium. For every chemical composition of these alloys it is thus essential to A commercially available PM Al-5•5Zn-2•5Mg-1•6Cu point out that liquid phase sintering promotes the basic (wt-%) alloy has been used to study the eVect of mechanisms for neck formation, the development of the elemental Mg additions, ranging from 0 to 4•5 wt-%, alloys and constitution of their microstructure. Speci c on its sinterability and mechanical properties after chemical compositions are designed to obtain heat treatable sintering and heat treatment of the W and T6 type.alloys with enhanced mechanical strength. DSC experiments were performed to study the chemical A great deal of research has been conducted to study reactions occurring during sintering. Results obtained the sinterability of binary 1 7 ,1 8 , 2 1 -2 4 and more complex 1 9 , 2 4 -2 9 from dilatometry and DSC experiments were used to Al alloys. These works report on the in uence of sintering aid determination of the optimum sintering cycles parameters, such as atmosphere, temperature, heating rate, under nitrogen. DSC experiments performed on as particle size, and type of the metallic additions, amongst sintered samples were used for the determination of the others, on the mechanical properties and the dimensional solution treatment temperature. The microstructure stability of the compacts. Liquids in these systems may form obtained after sintering of the experimental Al alloys by melting of the additives themselves or through a eutectic was characterised by SEM and XRD. The mechanical reaction between Al and the added metallic powders. properties of the alloys, both, in the as sintered andAlthough there is a certain degree of controversy on the heat treated states were obtained from tensile testing way to introduce the alloying elements, the use of prealloyed and hardness measurements. Additional theoretical powders represents an obvious alternative and more research calculations, using the THERMOCALC programme, is needed in this area. At present, its utilisation has been along with the experimental observations, were carried pointed out as unattractive because of diYculties during out as an alloy design method to suggest an alternative compaction 1 9 in spite of apparent advantages related to chemical composition and alloying strategy aimed at the dimensional stability of the compacts. 1 8 upgrading the sintering behaviour and mechanicalOther authors, mainly working on binary alloys, 1 6 ,1 7 ,2 0 , 2 4 ,3 0 properties of the present alloy.PM/0987 have also carried out metallographic analyses on specimens subjected to diVerent sintering conditions, while fewer works The authors (

Sintering behaviour of Al-6061 powder produced by rapid solidification process

“…[7][8][9][10] On the other hand, major improvement on sinterability of Al alloys (primarily 7xxx and 2xxx series) containing Pb, Sn and Sb have been achieved through liquid phase sintering. [11][12][13][14][15][16] Silicon is one addition that is now commonly used due to several property gains. 17 To increase the elastic modulus, it is common to incorporate hard ceramic phases such as SiC, Al 2 O 3 or B 4 C. 17 This paper uses the Taguchi design of experiments approach to characterise the press sinter response of an Al-6061 alloy powder produced by rapid solidification.…”

Effect of waxing on the properties of Al-1Mg P/M alloy

“…Fax: +902642956424. this reason enhanced the mechanical features (Kondoh et al, 2001). The new scientists (Martin et al, 2002) have concluded that rising the Mg content equal to 3.5 wt % in 7xxx series enhanced the mechanical strength better than the present commercial alloy. Moreover, it was mentioned (Lumley and Schaffer, 1996) that at elevated Mg contents, the inferior phase could not be completely dissolved in solid solution and therefore stayed as a complex at the grain boundaries resulting embrittlement of the alloy.…”

“…This was feasible by a liquid phase sintering (LPS) course resulting to enhance densification of the alloys. In the reported papers, the cause of trace addition of chosen elements such as Pb, Sn and Sb on the sinterability of Al alloys was examined (Martin et al, 2002;Lumley and Schaffer, 1996;Schaffer et al, 2001;Schaffer and Huo, 1999;Sercombe and Schaffer, 1999;Sercombe, 2003). It was understood that microalloying with 100 ppm of Pb (0.12 wt% Pb) supplied the superlative sintering reaction and enhanced the ultimate tensile strength (UTS) by 36% from 214 to 427 MPa of an Al-Zn-Mg-Cu alloy formed from premixed elemental powders (Sercombe, 2003).…”

An Evaluation of Severe Plastic Deformation on the Densification Behaviour of Powder Metallurgy Aluminium Alloy Al-Mg-Si-Cu-Fe and Al-Zn-Mg-Cu

“…An essential requirement for effective liquid phase sintering is a wetting liquid. Based on thermodynamically approach, magnesium reacts with aluminium oxide forming spinel, facilitating the disruption of oxide layer and thus wetting by liquid (Ziani & Pelletier, 1999); (Martín et al, 2002); (Martín & Castro, 2003). The reaction may be facilitated during sintering by diffusion of the magnesium through the aluminium matrix and will be accompanied by a change in volume, creating shear stresses in the film, ultimately leading to its break up.…”