William Hall Wendel, 76, retired president of the Carborundum Co. and the Kennecott Copper Corp. Graduated from the U.S. Naval Academy and the Harvard Business School, Wendel joined Carborundum after World War II, rising to president by 1962. When Carborundum was sold to Kennecott in 1977, he became president of Kennecott, retiring in 1980. During his retirement, he served five years as chairman of Polaris Industries, Minneapolis manufacturer of all-terrain vehicles. On Dec. 3 in Savannah, Ga., of a heart attack.