Formation of a TiAl₃ layer by an AIH-FPP treatment using mechanically milled particles and its wear resistance

In order to form a Ti?Al intermetallic compound layer on a carbon steel surface, an atmospheric-controlled induction heating fine particle peening (AIH-FPP) treatment was performed at 1000°C in argon atmosphere. The shot particles were prepared by a mechanical milling method. Titanium and aluminum particles at molar ratios of one to three were mechanically milled by a planetary ball mill for 6 h. The treated surface was analyzed using a scanning electron microscope, an energy dispersive X-ray spectrometer and X-ray diffraction. The reciprocating dry wear tests were performed under the following conditions; an opposing material of alumina balls of 3 mm in diameter, a load of 2.0 N, a sliding speed of 600 mm/min and a sliding distance of 224 m. The results showed that a Ti-Al intermetallic compound layer consisting mainly of TiAl3 formed on the surface of carbon steel by AIH-FPP treatment. This was because the shot particles were transferred to the substrate and the aluminum and titanium in the particles reacted neither excessively nor insufficiently. The AIH-FPP treated surface showed a higher wear resistance than that of the un- treated surface. This was because the wear mode of carbon steel changed from abrasive wear to adhesive wear owing to the formation of the Ti-Al intermetallic compound layer on the surface.