Sensitization means precipitation of carbides present at the grain boundaries in alloy and causing the alloy to be susceptible to intergranular corrosion. Intergranular corrosion is caused by the segregation of impurities and precipitates at the grain boundaries or by enrichment or depletion in the grain boundary. Sensitization in aluminum composites is an serious problem which is identified by the gradual formation and growth of beta phase Mg 2 Al 3 at grain boundaries, which increases the susceptibility of alloys to intergranular corrosion (IGC) and intergranular stress-corrosion cracking (IGSCC)