Background:

Tom Bayha joined ATI Allvac in July 2001 as Director of Superalloy R&D Technology.  He managed various product development programs in Ni-base alloys and high strength steels, before transferring to his position as Director of the Titanium R&D research group in 2005.  Since his arrival at ATI Allvac,

Tom has been the R&D Administrator of government-sponsored R&D programs, and was the Program Manager of the AFRL Metals Affordability Initiative Program on Electron Beam Single Melting of Ti-6Al-4V.  In January of 2009, Tom was named to his current position as the Director of Research and Development for ATI Allvac.

Prior to joining ATI Allvac, Tom was employed from 1991 to 1997 at Lockheed Martin Aeronautical Systems Company as a Senior Engineer.  In this capacity, he was the Principal Investigator for Metallic Materials Durability for the NASA High Speed Civil Transport Program, and the Program Manager of Ti-6-2-2-2-2 Characterization Program, funded by AFRL.

Tom also worked as an R&D process engineer at Heraeus MTD from 1997 to 1999, where he led development efforts in high purity titanium and magnetic material sputtering targets for electronic materials applications.  Subsequent to that position, Tom spent two years (1999 to 2001) at the Howmet Research Corporation, where he was the Program Manager for all externally funded Ni and Ti research programs.

Tom’s interests and hobbies include mountain biking, hiking, and Carolina athletics and chili peppers of all varieties.

Abstract:

Melt-related inclusions in titanium alloys are an ongoing concern for the titanium industry.  The typical titanium alloy material for aerospace applications or other commercial uses is melted by the VAR-VAR process, where high density (HDI) and Type I inclusions can survive the melting processes to ingot. 

Cold hearth melting methods offer many processing benefits to titanium alloys, in particular the ability to eliminate high density inclusions and dissolve lower density inclusions prior to the molten material entering the ingot mold.  The plasma arc melting (PAM) process, developed over the last two decades for melting conventional Ti alloys, is a type of cold hearth melting that has unique advantages in the production of highly alloyed titanium alloys. These include: 

• ·Good chemistry control, particularly for Al and other volatile elements, due to the presence of an inert He gas atmosphere;

• ·An ability to accommodate a wide choice of raw materials of various chemistries and product forms due to the hearth melting process; and

• Control of ingot structure due to the independence of melt rate and solidification conditions. 

Based on its history of successfully casting highly alloyed titanium ingots with precise chemistry, ATI Allvac has leveraged its extensive experience for the production of Ti-5-5-5-3 ingot for aerospace structural applications. 

Titanium alloy 5-5-5-3 (Ti-5Al-5V-5Mo-3Cr) is a near beta titanium alloy intended for fatigue and fracture toughness limited aircraft structural applications requiring superior tensile strength when compared to beta processed alpha/beta titanium alloys.  Its ability to be forged into complex shapes and heat treated to above 180 ksi ultimate tensile strength makes it a promising titanium alloy material for advanced structure and landing gear applications over traditional Ti alloys such as Ti-6Al-4V and Ti-10V-2Fe-3Al. 

The mechanical properties of alloy Ti-5-5-5-3 are developed by sub-transus solution heat treat or supra-transus beta anneal and appropriate aging to control grain size and precipitation in the wrought microstructure.