A turbine rotor blade with a tip cap section bonded to a tip end of the blade airfoil section, the tip cap section forming a separate cooling passage for the blade tip with a series of impingement chambers and diffusion chambers extending from a leading edge cooling air supply channel to a trailing edge exist hole. The chambers are formed by slanted ribs and a thin thermal skin is bonded to the ribs and upper and bottom surfaces to form an airfoil surface for the tip cap section. a blade with a damaged tip section can be repaired by removing the damaged section and bonding a tip cap section to the remaining surface of the blade to form a reusable rotor blade.