A Comprehensive Study Has Been Carried Out To Understand The Influence Of Various Thermodynamic And Kinetic Factors Such As Temperature, Alloying Element, Processing Method, Volume Fraction And Size Of Reinforcement On The Formation Of Al4C3 In Al/Sicp Composites. By Combining The Wilson Equation With The Miedema Model A Thermodynamic Model Has Been Developed To Understand The Influence Of Thermodynamic Parameters On The Formation Of Al4C3 In Sic Reinforced Multi Component Wrought And Cast Al Alloy Based Composites. To Validate The Thermodynamic Model And To Understand The Influence Of Various Kinetics Factors On The Formation Of Al4C3 In Al/Sicp Composites A Novel Extraction Procedure Was Developed By Salt Flux Addition Technique. This Salt Flux Extraction Process Enables The Use Of XRD To Identify The Interfacial Reaction Product, Al4C3, In Al/Sicp Composites Even In The Early Stages Of Reaction. It Also Allows In Quantifying The Interfacial Reaction Easily And More Accurately Even In Multi Component Alloys Based Al/Sicp Composites Using Spectroscopic Techniques Like Optical Emission Spectroscopy (OES). The Thermodynamically Developed Results Are Experimentally Validated For Pure Al/Sicp, 2124 Al/Sicp, A356 Al/Sicp And A319 Al/Sicp Composites. Experimentally Calculated Results Agree Well With The Thermodynamically Calculated Results In High Si Content (> 4.5 Wt. %) A356 Al/Sicp And A319 Al/Sicp Composites. However, In Low Si Content Pure Al/Sicp And 2124 Al/Sicp Composites (I) Large Deviation Between Thermodynamically Calculated And Experimental Equilibrium Si Contents To Suppress The Al4C3 Formation And (Ii) Strong Influence Of Reinforcement Size And Volume Fraction On The Extent Of Al4C3 Formation Has Been Observed. Formation Of 3 – 4 Μm Thick Protective Layers Of Al4C3 Crystals Over Sic Surface Is Recognized As A Reason For The Above Mentioned Behavior