The aluminium-silicon (Al-Si) based on Metal Matrix Composites (MMCs) is widely used in lightweight
constructions and transport applications requiring a combination of high strength and ductility. A grain
refinement plays a crucial role in improving characteristics and properties of Al alloys. In this investigation,
titanium diboride (TiB2) and scandium (Sc) inoculants were added to the Al-Si alloys for grain refinement of
an alloy. In this investigation, the corrosion resistance rate of Al-Si cast alloy reinforced by TiB2 and Sc were
measured by potentiostat (AUTOLAB) instrument. The aim of this research is to investigate the corrosion
rate for Al-Si-TiB2-Sc composites that immersed in different concentration of acidic solutions. Besides, the
immersion time of acidic solutions also was investigated. All the samples were prepared accordingly for
ASTM standard by the composition of 6.0 wt% TiB2 and 0.6wt% Sc. All the samples undergo cold mounting
technique for easy handling on corrosion tests. Then the samples were immersed in two different
concentrations acidic medium solutions, which were 0.1.and 1.0 M hydrochloric acids (HCl). The corrosion
rate also was investigated for immersion samples of 1.0 M HCl for 21 days. From the results obtained, added
TiB2 and Sc onto Al-Si alloy gave the better properties in corrosion resistance. Corrosion rates to reduce when
the samples were immersed in a lower concentration of acidic medium, 0.1 HCl. However, there are some
significant on the result but it still following the corrosion rates trend. Thus, improvements to reinforcement
content need to be done in further research to cover the lack of this corrosion rates trend.
This study investigates the effect of oxalic acid at different concentrations as doping agent on
the electrical properties of polyaniline (PANI). The polymerization of aniline to produce
PANI was carried out in media containing oxalic acid at 0.08 M, 0.09 M, 0.1 M, 0.2 M and
0.3 M in the presence of ammonium persulphate as oxidizing agent. The successful formation
of PANI doped with oxalic acid was confirmed by FTIR and the morphology studied using
XRD. An impedance investigation on the series of PANI formed revealed that doping in 0.1M
oxalic acid produced PANI of the highest conductivity of 2.52 x 10-6
Scm-1.