Piston manufacturing method and piston

Abstract

The invention belongs to the technical field of machining, and discloses a piston manufacturing method and a piston. The piston manufacturing method comprises the steps that the top surface of a piston matrix is coated through magnetic control injection to form a metal layer, wherein the metal layer is a composite metal layer of aluminum oxide and zirconium oxide; and electrochemical reaction is performed on the metal layer by adopting a micro-arc oxidation mode to form a ceramic layer, wherein the ceramic layer is of a hole-shaped structure. According to the piston manufacturing method, aluminum oxide is added on the basis of zirconium oxide due to the composite metal layer of aluminum oxide and zirconium oxide, so that the heat capacity of the metal layer is effectively reduced, the situation that the temperature of a combustion chamber rises because heat insulation stores a lot of heat is avoided, and sufficient combustion of fuel is facilitated. At the same time, the ceramic layeris of a loose structure and has low heat capacity, so that the heat capacity of the piston matrix is further reduced. In addition, the air heat conductivity coefficient in a micro-hole coating is extremely small, and the heat conductivity of air is poor, so that heat transfer from high-temperature gas to the piston matrix can be hindered, and the heat conductivity of the piston matrix is effectively reduced.

Description

technical field [0001] The invention relates to the technical field of machining, in particular to a method for manufacturing a piston and the piston. Background technique [0002] The production and manufacture of the existing piston has the following two methods: [0003] The first one is to coat the top of the steel piston with thermal barrier ceramic layers such as YSZ and Mg-PSZ. The main material of the ceramic layer is zirconia, and the low thermal conductivity of zirconia is used to reduce heat transfer and loss. Due to the high density of zirconia, the heat capacity is large, usually 2000kJ / (m 3 K) above will cause the zirconia coating to store a large amount of heat during heat insulation, thereby increasing the temperature of the combustion chamber and reducing the number of oxygen atoms entering the combustion chamber, which is not conducive to the full combustion of fuel. [0004] The second is to prepare a steel piston with a metal-ceramic composite coating. ...

AI Technical Summary

Problems solved by technology

However, arc spraying technology has the following disadvantages: (1) The metal layer prepared by arc spraying has a relatively large porosity and is distributed throughout the metal layer, which will cause the metal layer to be unable to be tightly bonded to the steel piston substrate, and coating may occur. (2) Arc spraying will generate high temperature on the surface of the steel piston, which may lead to a decrease in the high temperature strength of the steel piston substrate

In addition, although a metal-ceramic composite coating has been prepared on the surface of the steel piston, the coating does not have excellent low thermal conductivity and low heat capacity.

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