Reports of many functional deficiencies are these days rampant in many aluminium products flooding the Nigeria markets. These emanate from the local aluminium manufacturing, cottage foundry industries and much more from goods imported in the country. The study investigates the metallurgical properties of as-received and cast aluminium alloy samples used in the floating piston/calliper of the automobile hydraulic master brake cylinder. Commercially available aluminium alloy is procured from which callipers were cast and characterised. The study compares the physical properties by Hardness test, microstructural properties using high resolution metallurgical microscope, X-Ray Diffraction, chemical composition using Atomic Absorption Spectrophotometry. The as-received samples are characterised by poor metallurgical qualities such as variation in weight and density, low HBN, low tensile strength, high porosity and sand inclusions from the previous poor casting practices, hence abnormalities result under usage. The aluminium alloy was technically cast at pouring temperature higher than 750 oC using sand mould of high permeability. The casting gave higher HBN values of eutectic-AlSi structured aluminium alloy. The tensile strength calculated as approximate relationship between the hardness and the tensile strength, gave lower 329.09 Mpa and 154.78 Mpa strength for as-received samples as compared with the cast alloy having 353.58 Mpa and 226.49 Mpa tensile strength values respectively.

Cathodic protection is still one of most useful methods of corrosion control applicable to metal surfaces. Copper is often applied on steels for its good adhesion and improved appearance. Organic additives to plating baths improve the throwing power, levelling and brightening of the film. Hence the effects of surface polishing grit and Saccharin-550 additive on copper plating of steels were studied. Two standard NST60Mn and NST50-2 steels were electroplated in acid-sulphate bath using saccharin-550 as additive. Copper film thickness reduces as surface polishing grit increased with or without additive. The film properties improve as the substrate surface improves, with the most stable, metallic, lustre and adhesion obtained on 400µm and 600µm finishes without additive. Increasing saccharin-550 concentration from 0.1g/l to 0.5g/l improved film quality. Lower 0.1g/l saccharin-550 concentration produced higher thickness but poor brightening. Optimum plating parameters were obtained at 2V, 200g/l CuSO4.H2O, 600µm SFG and 0.5g/l saccharin. The density of copper plates is increased while porosity is reduced. The coat becomes more tenacious and protective in nature, and deposited in form of metal sheet rather than the powdery form. Types of steel do not control Cu-deposition but rather the polishing grade of steel surface.