**2. Experimental procedure**

The base material, Al powder with 99.9% purity was purchased from NovaScientific (M) Sdn Bhd. The sintering additives to facilitate liquid phase

### *Assisting Liquid Phase Sintering of Pure Aluminum (Al) by the Tin Addition DOI: http://dx.doi.org/10.5772/intechopen.101507*

sintering of Al utilized elemental powders of Sn (99.5% purity) and Mg (99.9% purity) were supplied by NovaScientific (M) Sdn Bhd and Sigma Aldrich (M) Sdn Bhd, respectively. The information on the purity of these starting materials was provided by the respective suppliers. To observe the behavior of liquid phase sintering of Al alloys, varied content of Sn between 1.5, 2, and 2.5 wt.% and a constant 1 wt.% of Mg was added. Moreover, pure Al without the addition of Sn and Mg constituents was set as the reference material prior to study the effects of Sn and Mg in assisting liquid phase sintering of Al. As schematically illustrated in **Figure 1**, a powder metallurgy technique of mixing, compaction, and sintering was implemented to fabricate a sintered Al alloy. In this process, table-top ball milling was employed to prepare the elemental powder mixture comprised of Al, Sn, and Mg. The mixing was conducted for 2 h with the ball to powder ratio of 1 to 10, where zirconia balls were used as the ball milling medium to produce a homogenous elemental powder mixture. Consequently, the elemental powder mixture was pressed into cylindrical pellets of 10 mm diameter and 6 mm height under a constantly applied pressure of 250 MPa. Then, the compacted specimens were sintered under a protected environment of argon (Ar) gas at 580°C for 2 h to obtain pure sintered Al alloys. The sintered alloys were then cleaned with acetone to remove impurities, followed by drying in an oven for 12 h to prepare them for characterization. The microstructure of as received starting materials and elemental powder mixture were analyzed under scanning electron microscopy (SEM) (SEM, Jeol JSM6500F, JEOL Ltd., Tokyo, Japan) before they were employed to fabricate the sintered Al alloy. The step was essential to develop satisfactory sintered Al alloys
