Monday - Friday, 6:00 - 7:00 PM ET Intel CEO Lip-Bu Tan said Monday that the company's external manufacturing business is gaining traction, emerging as a key piece of the chipmaker's turnaround. "Foundry is very important," Tan told Jim Cramer on CNBC's " Mad Money ." "It's one of the key national treasures." Intel's manufacturing business, known as foundry, is of the most expensive and crucial parts of the company's revitalization strategy. It is designed to manufacture semiconductors for