Accession Number:

ADA581368

Title:

Understanding Nanoscale Thermal Conduction an Mechanical Strength Correlation in High Temperature Ceramics with Improved Thermal Shock Resistance for Aerospace Applications

Descriptive Note:

Final rept. 1 Aug 2010 - 31 Jul 2012

Corporate Author:

PURDUE UNIV LAFAYETTE IN

Personal Author(s):

• Tomar, Vikas

Report Date:

2012-08-08

Pagination or Media Count:

44.0

Abstract:

This research focused on obtaining an understanding of the nanoscale physical mechanisms that govern interfacial interactions and heat transfer in materials at elevated temperatures. The underlying strategy was to understand how thermal conduction at nanoscale gets affected by factors such as the effect of quantum to molecular scale temperature related phase change, effect of nanoscale interfacial reconstruction, and effect of thermal stress affected material transformation. Issue is to enhance thermal management characteristics of materials exposed to high heating rates and high thermal gradients based on understanding gained in this research as well as to leverage this understanding to resolve thermal shock and thermal cycling affected failures in materials exposed to temperature extremes by introducing control factors related to nanoscale thermal conduction. Material systems of focus are Si based ceramics, particularly ZrB2-SiC nanocomposite interfaces. For verification purposes analyses also focus on Si-Ge interfaces and nanocomposites, as a lot of simulation data is available on this system.

Descriptors:

• *AEROSPACE SYSTEMS
• *CERAMIC MATERIALS
• *CORRELATION
• *THERMAL CONDUCTIVITY
• HEAT TRANSFER
• INTERACTIONS
• INTERFACES
• PHASE TRANSFORMATIONS

Subject Categories:

• Ceramics, Refractories and Glass
• Thermodynamics
• Astronautics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE