Dr. Ching-Feng "John" Chang ( 張清鋒) , 79, of Houston, TX passed away on Thursday, October 9, 2025, at home with family in Rochester, MN. John was born on May 16, 1946, in Changhua, Taiwan to his parents Jin Xiu Tai and Tian Zhou Chang. He was the second oldest of five siblings.

After earning his B.S. in Chemical Engineering from Tunghai University in 1968, he immigrated to the United States for graduate school. He received his M.S. from Rensselaer Polytechnic Institute in 1971 and his Ph.D. in Chemical Engineering from Princeton University in 1976. He went on to earn an MBA from Ohio University in 1979 and taught chemical engineering courses in his spare time as an Adjunct Professor at Cleveland State University. In 1974, John married Shun-Tang "Susan" Chang, and the couple settled in Cleveland, Ohio, where they raised three daughters: Connie, Patricia, and Cathleen.

John worked for Union Carbide and subsequently GrafTech, for 38 years. A world-renowned expert on carbon materials, he traveled extensively – to Japan, South Africa, Europe, China, and Brazil – and was honored as a Senior Corporate Fellow by Graftech (1995-2014). In 2011, he and his colleagues received an R&D 100 Award for one of his many patents. After several years of consulting, John retired in 2014 and moved to Houston, TX.

John loved classical and country music, traveling, reading, good food, and giving back through charity work. He will be remembered as a devoted husband, loving father, and cherished friend and colleague.

He is survived by his wife, three daughters, four grandchildren, two younger sisters, and a younger brother.

A memorial service for Dr. Chang will be held on Sunday, October 19th, 2025, in the River Park Chapel at Macken Funeral Home.

In lieu of flowers, the family requests that memorial gifts be designated to support research at Mayo Clinic ( https://give.mayoclinic.org/ ) or to the Tzu Chi Foundation ( https://donate.tzuchi.us/ ).

Online condolences are welcome at www.mackenfuneralhome.com