Wear Behavior Of Sintered Magnesium Matrix Composites Reinforced With Mg_2si Particle Under Wet Sliding Conditions

摘要

For evaluation of wear behavior in the sliding conditions, powder metallurgy Mg97Y_2Zn_1 alloy composites reinforced with additive Mg_2Si particles prepared via the repeated plastic working (RPW) process were investigated. The RPW process was effective in refining Mg_2Si particles of 5 to 10 wt% and grains of the matrix via dynamic recrystallization. When increasing the repetition number of RPW process from 200 to 600 cycles, the particle size of Mg_2Si additives changed from 8 μm to 1～2 μm, and the grain size of the magnesium matrix was 1 μm or less. With regard to the defensive and offensive behavior in wet wear test, this composite had superior adhesive wear resistance compared with the conventional magnesium alloys because of its high matrix hardness at elevated temperature. The uniform distribution of refined Mg_2Si particles was useful for improving both defensive and offensive properties against AZ31B counter disk specimens. Deep scratches of the disk surface were caused by coarse Mg_2Si additives, and resulted in an unstable and high friction coefficient.