EFFECT OF HARDNESS ON FRETTING WEAR CHARA CTERISTICS OF AC9B AND AC8AALUMINUM-ALLOYS

The fretting wear characteristics of JIS-AC9B and JIS-AC8A aluminum al loys were evaluated using a fretting wear testing machine in order to reveal the effect of the hardness on the fretting wear resistance. An oscillatory normal load (98 N) combined with a rotational vibration (6 .8 x 10(-2) rad) was imposed on the contact region between a spherical rider (case-hardened steel) and a flat rotor (JIS-AC9B or JIS-AC8A). The hardnesses of the rotor specimens were varied by changing the agin g time at 523 K. The wear scar area of JIS-AC9B and JIS-AC8A was decre ased linearly with increasing the rotor hardness at both room temperat ure and 523 K. It was considered that the adhesive wear mechanism was dominant in the fretting wear process of these alloys.