October_2021_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | O C T O B E R 2 0 2 1 1 9 W hen QuesTek Innovations formed in 1997, inefficient, costly, and time-consum- ing trial and error methods for materi- als design were the industry norm. The company’s engineers believed there was a better way—using the power of a mechanistic-based computation- al approach to shift from physical ex- perimentation to virtual simulation. By successfully implementing this trans- formative methodology over the past 25 years, the company’s unique ap- proach to integrated computation- al materials engineering (ICME) has reduced development costs and lead time, improved existing materials and processes, and enabled design and de- velopment of novel materials. QuesTek emerged as a leader in this area when its high strength, corrosion-resistant FerriumS53 steel became the first ICME- designed material to receive aerospace AMS and MMPDS qualifications and fly as a safety critical landing gear on the U.S. Air Force T-38 platform in 2010 [1] . The company also deployed the accelerated insertion of materials (AIM) process using expected chemistry and thermal process variation along with computational mechanistic models of alloy strength to create simulated data and estimate S53’s A-Basis 1% design minimums using only three full-scale data heats. Traditionally, full experi- mental generation of an A-Basis design minimum would require data from 10 full-scale heats of material [2] . Another standout among Ques- Tek’s recent developments is Ferrium C64, a commercially available steel de- signed for high-performance gearing. The alloy also serves as an enabling technology for future rotorcraft power transmission shafts, gears, and other mission-critical applications, such as those requiring weight savings, fatigue resistance, and temperature stability. The material, Fe-3.5Cr-7.5Ni-16.3Co- 1.75Mo-0.2W-0.11C, is the culmination of a rigorous design process that by- passed extensive physical experimen- tation—delivering a carburizable steel with unmatched capability. This article discusses the material design process for Ferrium C64. ANATOMY OF A MATERIAL DESIGN A systems-based methodology employing ICME technologies was used to design a novel alloy composition. Fundamental to the design process was the development of models predicting the interplay between processing, mi- crostructure, and key material prop- erties. The systems design chart for Ferrium C64 shown in Fig. 1 illustrates FERRIUM C64: A 21 ST CENTURY STEEL TAKES FLIGHT Ferrium C64 is the culmination of a rigorous design process that bypassed extensive physical experimentation — delivering a carburizable steel with unmatched capability. TECHNICAL SPOTLIGHT Carpenter Technology’s 22 metric ton vacuum induction melter where FerriumC64 is manufactured. Courtesy of Carpenter.