Effect of Rare Earth Elements on the Tribological Properties of Magnesium Alloys

Within a specific compositional range, magnesium alloys containing rare earth elements (RE-Mg alloys) exhibit significantly superior friction and wear characteristics compared to their rare earth-free matrix counterparts. The primary influences can be analyzed as follows:

1. Wear Resistance Enhancement

The incorporation of rare earth elements substantially enhances the wear resistance of magnesium alloys, which is mainly because rare earth elements can form stable phases in alloys, and these phases can effectively impede the movement of dislocations, thereby enhancing the hardness and strength of the alloys and reducing wear.

2. Load-Dependent Behavior

Both RE-containing and conventional magnesium alloys demonstrate accelerated wear rates with increasing applied loads, which suggests that under high loads, the wear mechanism of the alloys may change, leading to an increase in wear rate.

3. Wear Mechanism Modulation

The addition of rare earth elements fundamentally modifies the operative wear mechanisms in magnesium alloys. The specific wear behavior demonstrates significant dependence on operational parameters including contact pressure, sliding velocity, and ambient temperature, with rare earth elements altering the predominant material removal pathways.

4. Structural-Functional Integration Design

Strategic regulation of rare earth element composition enables the development of novel high-performance RE-Mg alloys with integrated structural and functional properties, which not only optimizes tribological performance but also concurrently enhances plasticity, thermal conductivity, and corrosion resistance - critical properties for engineering applications.

5. Performance Enhancement Mechanisms

The influence mechanism of rare earth elements on the performance of magnesium alloys includes improving the microstructure of the alloy, enhancing the strength of grain boundaries, and promoting fine grain strengthening, etc. These synergistic mechanisms collectively enable RE-Mg alloys to maintain exceptional ductility while achieving superior wear resistance and corrosion protection capabilities compared to conventional magnesium alloys.

 

Rare earth elements have a positive impact on the friction and wear performance of magnesium alloys. Through reasonable design and addition of rare earth elements, the comprehensive performance of magnesium alloys can be significantly improved, making them more suitable for industrial applications with higher requirements.