“Paying it forward” in technology—Wrapping a “Bow Tie” around what Bill Hillig started in CMCs 

by Todd Alhart

In 2016, GE and the Aviation industry celebrated a major materials milestone with the introduction of ceramic matrix composites (CMCs) in the CFM LEAP engine. Each of the more than 14,000+ engines now on order will have 18 shrouds made of this watershed material innovation.

This innovation, of course, was no small feat. The research and development of this new material spanned decades and several generations of GE researchers. But when you ultimately deliver a breakthrough that shattered the heat tolerance threshold of jet engine parts by not tens but hundreds of degrees, the journey was well worth it. And that is how advances in technology work, with every new generation of scientists and engineers building on the discoveries and breakthroughs of the last.

We pay it forward.

Recently, one of GE’s earliest research pioneers in CMCs, Dr. William (Bill) Hillig, passed way. He retired from GE’s Research lab after a successful 36-year career in 1989, long before most current GE research employees worked for Global Research. But those who had the privilege of working with him like chief scientist Krishan Luthra remember a true scientific visionary who was a thorough gentlemen in the truest sense.

Luthra, who was his manager for several years, said Bill’s contributions put us on the right path to commercialization, stating, “Bill had the vision back in the seventies to create silicon carbide (SiC) fiber reinforced silicon Si–SiC composites that ultimately led to the approach used to form CMC parts used in aircraft engines today.”

Luthra noted the work Bill did was key to later breakthroughs in achieving what’s called the “near net-shape” of parts. This means that when forming a part during the manufacturing process, it maintains close to its actual size and shape. Luthra said this was an essential barrier to break through to be successful in commercializing the CMC technology.

Following Dr. Hillig’s retirement from GE, he joined Rensselaer Polytechnic Institute (RPI) as a research professor in materials science. During his career, he held 12 patents and had more than 70 papers, reviews and book contributions published. Many of his papers focused on advanced materials, including high-temperature ceramics and ceramics composites.

Luthra said, “As we celebrate technical milestones today, it’s important that we look back and remember those before us whose work we built upon to get there. I’ll never forget Bill. Each day he came to work wearing a bow tie. It was kind of his trademark, and in a way symbolic.”

Luthra concluded, “When you tie a bow tie, you must bring two loose ends together. And that’s what we have essentially done with CMCs. We took the end he started and advanced the work he and his generation made to bring to market. And this journey continues with the present and future generations to come.”