ABSTRACT
Abrasion wear caused by sand particles is the prevailing mode of wear in the Arabic nations. The relative increase in the concentration of airborne dust is responsible for the wear increase. It is important to know that the abrasive wear represents more than 50% of all other types of wear due to the spread of sandy regions. Therefore, there is an increasing demand to develop the abrasion wear resistance of the polymeric coated surfaces to withstand the abrasive action of sand particles.
 
Experiments were carried out to investigate the abrasive wear of the test specimens caused by sand particles. Low-carbon steel and hardened steel specimens as well as specimens coated by thermoplastic composites were tested. Silicon oxide (SiO₂), aluminium oxide (Al₂O₃), iron, copper and glass fibre were used as filling materials in polyamide (PA6). Low-carbon steel was used as substrate. An abrasive wear tester was constructed to the wear caused by sand particles.
 
PA6 showed promising results, especially if both the concentration and grain size of the additives were carefully selected. The addition of iron and Al₂O₃ powders to PA6 showed a considerable mitigation in the wear process if their concentrations were controlled to a certain limit. The reinforcement used in the polyamide coatings were metallic wires, polypropylene and polyamide fibres. Also, filling polyamide coatings by copper, iron, molybdenum disulphide and graphite at concentration of 10 wt.% was tested. The polyamide coatings have been impregnated by 10 wt.% and 20 wt.% of SAE 30 oil.
 
Besides, polyamide coatings filled by 10 wt% iron powder and impregnated by 10 wt.% oil showed significant wear resistance. Also, polyamide fibres as filling material in polyamide coatings enhanced the abrasive wear resistance. This enhancement increased with increasing the fibre concentration and decreasing the fibre diameter. Tin coated steel wire as short fibres reinforcing polyamide coatings gave the minimum wear.