FORMING Al-Al2O3 NANOCOMPOSITE SURFACES USING FRICTION STIR PROCESSING

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Transactions of NAMRI/SME

OSTI ID:958938

Qu, Jun ^[1]; Xu, Hanbing ^[1]; Feng, Zhili ^[1]; An, Ke ^[1]; Battiste, Rick ^[1]; An, Linan ^[2]; Heinrich, Helge ^[2]

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1. ORNL
2. University of Central Florida

This study presents a solid state surface engineering process to form a nanocomposite layer on aluminum surface. Friction stir processing (FSP) was used to stir and mix nano-sized Al2O3 particles into a commercially pure aluminum surface to form an Al-Al2O3 nanocomposite layer of up to several millimeters thick. Compared with a non-processed aluminum surface, a nanocomposite surface with 15 vol% nano-particles has demonstrated increased hardness (by 3X) and yield strength (by 10X), and reduced friction coefficient (by 55%) and wear rate (by 100X). Transmission electron microscopy (TEM) has revealed high matrix dislocation density in the nanocomposite surface that is believed to be largely responsible to such significant property improvements. Neutron diffraction measurements suggested tensile residual stress in the aluminum matrix. The stress was mainly induced by thermal-expansion-mismatch between aluminum and alumina.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Flux Isotope Reactor; High Temperature Materials Laboratory
• Sponsoring Organization: ORNL LDRD Director's R&D
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 958938
• Journal Information: Transactions of NAMRI/SME, Journal Name: Transactions of NAMRI/SME Vol. 37
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
DISLOCATIONS
FRICTION
HARDNESS
NEUTRON DIFFRACTION
PROCESSING
TRANSMISSION ELECTRON MICROSCOPY
YIELD STRENGTH