Albion College Mathematics and Computer Science Colloquium

Title: Mesocale Modeling of Damage Nucleation in Titanium Aluminum Grain Boundaries

Speaker: Darren E. Mason
Associate Professor
Mathematics and Computer Science
Albion College
Albion, Michigan

Abstract: Is there a way to predict when and where such failure occurs? In this talk I will discuss some recent research directed at providing answers to these critical real-world problems. After a brief tutorial on the basic math, physics, and metallurgy required to attempt to answer such questions, I will review prior work that used a well characterized patch of Titanium Aluminum (TiAl) to evaluate the utility of a scalar fracture initiation parameter (fip) to predict the relative resistance of grain boundaries to microcracking when subjected to stress. I will then discuss new research that has generalized the idea of a scalar fip to a physically motivated damage tensor D that measures the amount of physical damage that accumulates at stressed grain boundaries as they evolve through space and time. Local lattice curvature near the grain boundary, local elastic and plastic stress evolution, and accumulated dislocation content at the grain boundary are among the quantities considered. Then, using data generated from a three dimensional, nonlinear, crystal plasticity finite element simulation of the same experimental TiAl region, the ability of this the tensor D to predict the location of "weak" grain boundary locations where micro-cracking is likely to occur.

This work is funded by the NSF Materials World Network Grant DMR-0710570, the Deutsche Forschungsgemeinschaft (DFG) Grant EI 681/2-1, and the Department of Mathematics and Computer Science at Albion College.

Location: Palenske 227

Date: 9/23/2010

Time: 3:10

@abstract{MCS:Colloquium:DarrenEMason:2010:9:23, author = "{Darren E. Mason}", title = "{Mesocale Modeling of Damage Nucleation in Titanium Aluminum Grain Boundaries}", address = "{Albion College Mathematics and Computer Science Colloquium}", month = "{23 September}", year = "{2010}" }

Title:	Mesocale Modeling of Damage Nucleation in Titanium Aluminum Grain Boundaries
Speaker:	Darren E. Mason Associate Professor Mathematics and Computer Science Albion College Albion, Michigan
Abstract:	Is there a way to predict when and where such failure occurs? In this talk I will discuss some recent research directed at providing answers to these critical real-world problems. After a brief tutorial on the basic math, physics, and metallurgy required to attempt to answer such questions, I will review prior work that used a well characterized patch of Titanium Aluminum (TiAl) to evaluate the utility of a scalar fracture initiation parameter (fip) to predict the relative resistance of grain boundaries to microcracking when subjected to stress. I will then discuss new research that has generalized the idea of a scalar fip to a physically motivated damage tensor D that measures the amount of physical damage that accumulates at stressed grain boundaries as they evolve through space and time. Local lattice curvature near the grain boundary, local elastic and plastic stress evolution, and accumulated dislocation content at the grain boundary are among the quantities considered. Then, using data generated from a three dimensional, nonlinear, crystal plasticity finite element simulation of the same experimental TiAl region, the ability of this the tensor D to predict the location of "weak" grain boundary locations where micro-cracking is likely to occur. This work is funded by the NSF Materials World Network Grant DMR-0710570, the Deutsche Forschungsgemeinschaft (DFG) Grant EI 681/2-1, and the Department of Mathematics and Computer Science at Albion College.
Location:	Palenske 227
Date:	9/23/2010
Time:	3:10