Dense black-spot-free iron-based powdery metallurgical self-lubricating CNG engine valve seat ring and preparation method thereof

Abstract

The invention discloses a dense black-spot-free iron-based powdery metallurgical self-lubricating CNG engine valve seat ring. The dense black-spot-free iron-based powdery metallurgical self-lubricating CNG engine valve seat ring is prepared from, by weight, 6.4-6.6 parts of chrome, 4.4-4.6 parts of cobalt, 0.7-1.2 parts of nickel, 0.3-0.5 part of neodymium, 2.3-2.6 parts of boron, 3.6-4.3 parts of polymerization iron powder, 16-18 parts of copper, 1.3-1.5 parts of nano molybdenum disulfide, 0.7-0.8 part of calcium fluoride, 1.2-1.4 parts of silicon carbide, 0.2-0.3 part of zinc chloride, 0.5-0.8 part of triethyl silane, 1-2 parts of glass fiber, 2-3 parts of high carbon ferro-chrome alloy powder and 62-65 parts of iron. The surface of the modified nano molybdenum disulfide is coated with a layer of copper film to serve as a solid lubricant which is added to a substrate material, meanwhile the silicon carbide, neodymium, boron and other ingredients are further added, metal particle phase change is changed by adopting sintering, infiltration and heat treatment processes, and the prepared product is uniform in texture, dense, stable and free of black spot and other defects.

Description

technical field [0001] The invention relates to the technical field of automobile engine accessories, in particular to a dense iron-based powder metallurgy self-lubricating CNG engine valve seat without black spots 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...

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.