The operational parameters improving of internal combustion engine parts

Abstract

The work is dedicated to improving the reliability and durability of parts of a piston cylinder group of internal combustion engines. Strengthening of machine parts is possible due to the application of special technological processes. Modern materials and coatings must meet high operating temperatures and loads. Chromium plating, boring and ion-plasma spraying do not meet the established quality requirements. The aluminium piston is destroyed in the area of the head. This is manifested in the accumulation of holes, channels, traces of alloy leaching. In addition, as a result of heating, the strength of the aluminium alloy is more than doubled.
It is proposed to create and apply a coating that can withstand operating temperatures above 2000 ° C, as well as pulsating loads. A detonation and gas spraying method is proposed. It is characterized by the versatility of materials: from polymers to refractory ceramics, precious metals and alloys. The sawn particles have high kinetic energy. The coating is characterized by high strength, reaching up to 180… 200 MPa, HRCe 60 hardness, minimum width. The temperature influence during spraying on the work piece is negligible. A sequence of preparatory operations is proposed. The piston and the heat ring on the UN-102 detonation gas plant were subject to hardening. A manipulator using the shot energy of the installation was used. The obtained surfaces are characterized by regular macrostructure (waviness). The application was subject to a nickelaluminium alloy. The coating thickness is 150… 270 microns, the hardness is HV 550, the adhesion to the base is 94…100 MPa.
The results of the studies on the details of the cylindrical piston group showed a decrease in operating temperatures due to the finalization of the coating and the high-quality seal of the combustion chamber. The durability of the rings is 1.6·106…2.3·106, which indicates a significant increase in fatigue resistance and work life. The proposed technology is suitable and recommended for implementation in batch production.