Publications
Showing 180 results for Author: Jun Qu
Oct, 2009
Journal
NEUTRON DIFFRACTION MEASUREMENT OF RESIDUAL STRESSES IN FRICTION STIR PROCESSED NANOCOMPOSITE SURFACE LAYER
Friction stir processing (FSP) was successfully used to stir and mix nano-sized Al2O3 particles into a Al6061-T6 aluminum plate to form a nanocomposite layer up to 3 mm thick. This nanocomposite surface has demonstrated significantly improved surface hardness, yield strength, and wear-resistance without sacrificing the substrate ductility and conductivity. Neutron diffract…
Sep, 2009
Journal
Ionic Liquids as Novel Lubricants and Additives for Diesel Engine Applications
The lubricating properties of two ionic liquids with the same anion but different cations, one ammonium IL [C8H17]3NH.Tf2N and one imidazolium IL C10mim.Tf2N, were evaluated both in neat form and as oil additives. Experiments were conducted using a standardized reciprocating sliding test using a segment of a Cr-plated diesel engine piston ring against a grey cast iron flat…
Jun, 2009
Journal
Tribological characteristics of aluminum alloys against steel lubricated by ammonium and imidazolium ionic liquids
Sliding friction and wear characteristics of aluminum alloys against AISI 52100 steel lubricated by ionic liquids (ILs) were investigated at both room and elevated temperatures. The tested aluminum alloys include a commercially pure aluminum Al 1100, a wrought alloy Al 6061-T6511, and a cast alloy Al 319-T6. The lubricating performance of two ILs with the same anion, one a…
Jun, 2009
Journal
FORMING Al-Al2O3 NANOCOMPOSITE SURFACES USING FRICTION STIR PROCESSING
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 nanocomposi…
Jun, 2009
Journal
Oxygen-Diffused Titanium as a Candidate Brake Rotor Material
Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surf…
Dec, 2008
Conference Paper
Tribological Characteristics of Single-phase AlMgB14 and Nanocomposite AlMgB14-TiB2 Superhard Coatings
This study investigated the friction and wear characteristics of AlMgB14 and AlMgB14-TiB2 superhard coatings, produced by pulse laser deposition (PLD) and physical vapor deposition (PVD), respectively. Tests were conducted under unidirectional and reciprocating sliding against AISI 52100 bearing steel in both dry and oil-lubricated conditions. The AlMgB14 coating exhibited…
Dec, 2008
Journal
Effects of Multiple Treatments of Low-Temperature Colossal Supersaturation on Tribological Characteristics of Austenitic Stainless Steels
An alternative carburization process, low-temperature colossal supersaturation (LTCSS), has demonstrated significant improvement on both wear- and corrosion-resistance for austenitic stainless steel surfaces in recent literature. This study explores the effects of multiple treatments of LTCSS on tribological characteristics for Type 316 stainless steel. Thicker carburized…
Mar, 2008
Conference Paper
PRODUCING A COMPOSITE SURFACE USING FRICTION STIR PROCESSING
Aluminum alloys would have much wider usage in bearing applications if their wear-resistance could be significantly improved. This investigation developed a solid-state surface engineering process to form an aluminum-alumina composite surface by friction stirring ceramic particles into an aluminum surface to improve the surface hardness and wear-resistance without sacrific…