Aerospace Metals Get Stronger, Lighter
In this AeroDef exclusive interview, Tim Armstrong, Vice President, Research and Product Commercialization for Carpenter Metals discusses the need for continued development of new lightweight, strong metals even as new composites grab the attention of the aerospace community. Advanced computer modeling and new nanostructures are leading to substantial stronger, lighter metals than ever.
AeroDef: How would you characterize the general attitude towards metals and the
development of new metals?
There is a perception in the world today that there’s no need for new metals—that we have everything that we’re ever going to need. Even in scientific and government funded research, we’re not putting any funding into developing the alloys we will need tomorrow for high-temperature engine components, for ultra high-strength structural components, for metals that will result in lightweighting of the aircraft to achieve greater fuel efficiency.
AeroDef: What would you suggest needs to happen to change that?
We need to change the paradigm on how we develop and take alloys to market. In the past, we let the aircraft designers dictate the materials that they wanted to use. They would design a component and choose a metal that would meet the properties for that part. They would then purchase only that material.
Today the paradigm is changing. What we’re seeing is that materials developers, manufacturers and designers are coming together in a collaborative effort, and they’re redesigning to the unique attributes of the metals in the marketplace.
What that allows you to do is, one, get your new alloys into the market faster, and it allows you to realize sales faster. Second, it shortens the qualification times for the OEMs to get the products into the market. It’s a win-win for everybody.
AeroDef: Are there other new ways of developing metals?
We now talk about ‘materials by design.’ Today, there are more design advancements being made on the computer, which takes the empiricism out of development, shortens the development time, and is going to allow us to manipulate the properties and the microstructure of alloys as we develop them.
The desire for everyone is to shorten development times. Otherwise, we won’t make the advances in technology that are necessary to drive better fuel efficiency.
AeroDef: What you are suggesting is that metallic materials will be undergoing perhaps fundamental change.
Yes, for instance take nanomaterials. Nanomaterials that will be a game changer are becoming a reality. Carpenter now has a product line where we’re producing small bar with very fine grain. In these materials, we are increasing strength by a factor of two and increasing the fatigue resistance by a factor of one and one half. This allows designers to make the same component substantially lighter and achieve the same properties.
If we apply this technique to Titanium, this could be a big game changer as this technology is scaled. It is also applicable to stainless steels, nickel-based alloys and aluminum.
AereoDef: Are there any new developments inmetal that you would like to tell my readers about?
We have a new alloy steel called PremoMet which is a very high strength, very fatigue-resistant alloy steel that is getting some visibility in transportation.
We also have a yet-to-be-named high-strength stainless steel. It’s the world’s strongest quench and tempered martensitic stainless steel and we are already fielding it into various aerospace tests for actuation systems and landing gear components.
AeroDef: How do you see the future of metals in aerospace?
I think the future of metals is bright. The future is going to be a combination of metals and composites, whether they are carbon fiber or plastic carbon or plastic fiber composites. I think everything’s moving towards lightweighting, improved fuel efficiency and revenue per flight hour.