July_August_AMP_Digital

HIGHL IGHTS 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 | J U L Y / A U G U S T 2 0 1 9 5 9 MS&T LECTURERS Continuing the grand tradition of ASM International events, three distinguished lecturers will speak at the 2019 Materials Science & Technology Conference and Exhibition (MS&T19) to be held September 29 – October 3 at the Ore- gon Convention Center in Portland. MS&T brings together the strengths of five major materials organizations: ASM International, The American Ceramic Society (ACerS), The Association for Iron & Steel Technology (AIST), The Minerals, Metals & Materials Society (TMS), and NACE International. 2019 Alpha Sigma Mu Monday, September 30 • 2:30 – 4:30 p.m. Prof. Diana Lados, FASM Milton Prince Higgins II Distinguished Professor Worcester Polytechnic Institute (WPI) “A Comparative Study of Ti-6Al-4V Alloys Fabricated by Three Pow- der-Based Additive Manufacturing Technologies: Integrative Design for Fatigue Performance and New Meth- ods for Rapid Material/Part Qualifications” Many additive manufacturing (AM) processes have been used for the fabrication and repair of Ti-6Al-4V com- ponents, and the use of various manufacturing methods exhibit different mechanical properties. This presentation compares the processing-microstructure-property relation- ships in Ti-6Al-4V alloys produced by three powder-based AM technologies: Laser engineered net shaping, electron beam powder bed fusion, and laser powder bed fusion. First, the thermal histories, microstructure evolutions, and tensile properties of the materials will be discussed. Next, the fatigue and fatigue crack growth behavior for different orientations, stress ratios, and heat treating conditions will be addressed, and damage mechanisms at different crack growth stages will be identified. The results will then be reviewed from the perspective of design for fatigue resis- tance and life predictions in high-integrity applications. Opportunities and directions towards qualifying structural AM parts will also be discussed, and a new and effective methodology for rapid materials characterization and pro- cess optimization for fatigue performance will be proposed. 2019 ASM/TMS Distinguished Lectureship in Materials and Society Tuesday, October 1 • 8:00 – 10:40 a.m. Prof. Carolyn M. Hansson Professor of Materials Engineering University of Waterloo, Canada “The Challenge of 100 Year Service- life Requirement” The highway authorities in Canada and the U.S. are considering raising the service-life specification for rein- forced concrete highway infrastructure from the current 75 years to 100 years or more. The goals are to reduce finan- cial and environmental costs and improve sustainability of the system by limiting the need for maintenance, remedi- ation, and replacement of the structures. In coastal areas and in the northern parts of North America and Europe, the major culprit in limiting the durability of reinforced concrete is salt, from seawater and de-icing agents. The chlorides destroy the natural passivity of reinforcing steel in con- crete and allow active corrosion, which eventually causes cracking and spalling of the concrete. De-icing agents con- taining calcium- or magnesium-chloride can attack the con- crete directly. This presentation will describe the research at Waterloo on identifying the most appropriate stainless steels to combat the chloride attack over the long term. 2019 Edward DeMille Campbell Memorial Lecture Tuesday, October 1 • 12:45 – 1:45 p.m. Prof. Katherine T. Faber, FASM Division of Engineering and Applied Science California Institute of Technology “Breaking Old Barriers: New Oppor- tunities in Brittle Fracture” The foundations for understand- ing brittle fracture were established nearly a century ago with the pio- neering work of Griffith, and later, using a continuum frac- ture-mechanics approach. These principles provide the basis for the design of structural ceramics and rely onmicro- structural solutions to overcome many of the limitations of brittle fracture. However, the improvement of such ceram- ics has been limited by the extent to which microstructure can be controlled. The advent of additive manufacturing as well as advances in more traditional solidification-based processing techniques offer new methods for both chemi- cal and microstructural control. By employing a theoreti- cal framework to design and optimize microstructures for enhanced fracture toughness, it is possible to identify both new candidate microstructures and new structural oppor- tunities for ceramics. Examples will be discussed, includ- ing a “fracture diode,” a dendritic porous membrane and a shape-memory ceramic, each of which benefits from opti- mized topology. Lados Hansson Faber MS&T 2019 LECTURERS ANNOUNCED