High-hardness iron-based powder metallurgy self-lubricating CNG engine valve seat ring and manufacturing method thereof

Abstract

The invention discloses a high-hardness iron-based powder metallurgy self-lubricating CNG engine valve seat ring. The high-hardness iron-based powder metallurgy self-lubricating CNG engine valve seat ring is made from, by weight, 6.2-6.4 parts of chrome, 4.2-4.4 parts of cobalt, 0.7-0.9 part of nickel, 0.5-0.7 part of titanium, 0.3-0.5 part of cerium, 18-19 parts of copper, 1.2-1.5 parts of nano molybdenum disulfide, 0.7-0.9 part of tungsten carbide, 1-2 parts of manganese dioxide, 0.4-0.6 part of methyl triethoxy silane, 2.1-2.4 parts of ferro boron powder, 0.2-0.4 part of aluminum dihydrogen phosphate, 2-3 parts of polytetrafluoroethylene powder and 64-68 parts of iron. According to the high-hardness iron-based powder metallurgy self-lubricating CNG engine valve seat ring, the surface of the modified nano molybdenum disulfide is covered with a layer of copper film to be added into a matrix material as a solid lubricating agent; and meanwhile, manganese dioxide, titanium, cerium and other elements are added, the sintering, melt infiltration and heat treatment process is adopted to change the phase change of metal particles, and the manufactured product has high hardness and high high-temperature stability.

Description

technical field [0001] The invention relates to the technical field of automobile engine accessories, in particular to a high-hardness iron-based powder metallurgy self-lubricating CNG engine valve seat and a manufacturing method thereof. Background technique [0002] Compressed natural gas (CNG), liquefied petroleum gas (LPG) and methanol as alternative fuels for internal combustion engines are effective ways to protect the environment and use energy rationally. my country is rich in natural gas resources, and its market prospect as a clean fuel for engines is huge. However, with the use of new energy sources, the operating conditions of auto parts, especially engine valve seat rings, will change, and new requirements are put forward for their materials. The intake and exhaust valve seat rings of CNG engines are important working parts to control gas intake and exhaust gas discharge. Under high temperature, they are subjected to the erosion of air flow and high-frequency i...

AI Technical Summary

Problems solved by technology

[0004] Because the valve seat ring has no oil lubrication in the working process, its weather resistance is poor, its service life is short, and its long-term wear resistance is poor. At present, there are few researches on the combination of adding hard particles, self-lubricating additives, etc. and adopting a new infiltration process.

In the literature, only the new process of infiltration is adopted, and the method is relatively single, and the obtained valve seat green body has poor toughness, poor cutting performance, low temperature resistance and short service life, etc.