Wear Behavior of Hot Rolled AZ31B and AZ31B-Nd-La Mg Alloys Tested at Different Angles to Rolling Direction

The aim of this study is to investigate the direction-based dry wear behavior of hot rolled AZ31B and AZ31B-0.5wt.%Nd-0.1wt%La alloys which were deformed with two rolling speeds of 4.4 and 29.5 rpm. The twins and dynamic recrystallization mechanisms were introduced on microstructure of studied specimens dependent on the rolling speeds, where 4.4 rpm rolling imparted to higher hardness than 29.5 rpm due to twinning. Linear reciprocating ball-on flats wear tests were employed to measure the wear rate of 90 degrees, 45 degrees and 0 degrees ways to the rolling direction. To understand the relationship between wear behavior and microstructure properties, the light optical microscopy (LOM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) methods were employed. AZ31B-0.5wt.%Nd-0.1wt%La alloy was diverse from AZ31B because of dense fiber-like Al-11(Nd, La)(3) and Al-2(Nd, La) secondary phases. AZ31B demonstrated more wear rate than AZ31B-0.5wt.%Nd-0.1wt%La alloy at 90 degrees, 45 degrees and 0 degrees direction of wear tests. However, the wear rates order was obtained as 45 degrees>90 degrees>0 degrees for both alloys rolled at 29.5rpm rolling speed. Thus, the pole figure analysis was studied to obtain the effect of macro-texture on the wear behavior of alloys, where the orientation distribution of (0002) texture around the normal direction is wider than TD (90 degrees) than RD (0 degrees) for both investigated specimens. Furthermore, the worn surfaces were investigated by SEM and energy-dispersive spectroscopy (EDS) to obtain which wear mechanism is dominant and how affect the wear resistance. Commanding wear mechanisms were obtained as abrasion, oxidation and delamination.