One method of fabricating complex aerospace components is diffusion bonding. We wish to join a nickel sheet, intended to rapidly transfer lightning strike data away from critical locations, to an FCC iron (stainless steel) plate. We find that we can accomplish a good bond in 8 hours when the two metals are joined at 800°C. How long will it take to obtain an equally good bond if we decide to perform the bonding at 600°C? (Assume that the quality of the bond is determined by the rate of diffusion into the FCC iron).