Influence of piston surface treatment on piston assembly friction in an eco-mileage vehicle engine

Abstract

This study investigated the effect on piston assembly friction after treating piston surfaces with a fine particle bombarding process, using a friction measurement apparatus with a floating cylinder liner, similar to an eco-mileage vehicle engine. Friction was measured in four conditions: (1) no treatment (standard piston in a commercially-available engine), (2) micro dimple treatment (45 μm ceramic particles were air-blasted onto the piston surface), (3) molybdenum disulfide (MoS2) shot treatment (1 μm MoS2 particles were air-blasted onto the piston surface), and (4) combination of the previous two micro dimple and MoS2 shot treatments (first 45 μm ceramic particles and then 1 μm MoS2 were air-blasted onto the piston surface). Results indicated that friction decreased in the following order: no treatment > micro dimple treatment > MoS2 shot treatment > combination of micro dimple and MoS2 shot treatments.

Keywords

• piston
• eco-mileage vehicle engine
• floating cylinder liner
• piston assembly friction
• fine particle bombarding