Titanium Nitride Coated Sliding Mechanism for Diesel Engine Friction Reduction
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Solution Overview
Problem
Existing sliding mechanisms with iron series materials, such as steel, fail to effectively form a lubricating film at sliding surfaces when using organic molybdenum lubricating oil additives like molybdenum dithiocarbamate (MoDTC) due to competition from other additives, particularly in diesel engine oils with high detergent-dispersant content, resulting in inadequate friction reduction.
Innovation Solution
Coating at least one sliding member with a titanium nitride-based material, such as titanium carbon nitride, titanium nitride, or titanium nitride aluminum, and adding molybdenum dithiocarbamate (MoDTC) to diesel engine oil with a high detergent-dispersant content, under specific lubricating conditions defined by the Sommerfeld number range, to enhance friction reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If organic molybdenum lubricating oil additive (MoDTC) is added to diesel engine oil, then friction reduction is expected, but the lubricating film cannot be sufficiently formed due to competition from detergent-dispersant additives
Solution Approach 1:
The invention changes the chemical composition parameters of the lubricant by specifying precise concentrations of MoDTC (600-1000 ppm) and detergent-dispersant (1.0-5.0% by weight), and changes the surface property parameters by coating sliding members with titanium nitride-based materials, thereby resolving the contradiction between friction reduction and lubricating film formation
Solution Approach 2:
The invention creates a composite lubrication system combining MoDTC additive with titanium nitride-based surface coatings on sliding members, where the coating material and lubricant additive work synergistically to form an effective lubricating film despite the presence of detergent-dispersants
2Object-generated harmful factors
If detergent-dispersant is added to diesel engine oil, then cleaning and dispersing performance is improved, but the lubricating film formation by MoDTC is inhibited
Solution Approach 1:
The invention optimizes the concentration parameters of both detergent-dispersant (1.0-5.0% by weight) and MoDTC (600-1000 ppm) to achieve a balance where both cleaning performance and friction reduction are maintained, and introduces titanium nitride-based coatings to enhance MoDTC's lubricating effect
Solution Approach 2:
The titanium nitride-based surface coating acts as an intermediary that facilitates the formation of MoDTC lubricating film on sliding surfaces, mediating between the detergent-dispersant-containing lubricant and the metal surface to enable effective friction reduction
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces friction and improves lubricating performance by allowing the molybdenum dithiocarbamate to form a lubricating film effectively, even in diesel engine oils with high detergent-dispersant levels, leading to marked improvements in friction coefficients and wear resistance.
Implementation Method 1
at least one of the sliding members is coated by a titanium nitride-based material, and a friction coefficient is reduced under certain specified conditions whereby low friction performance can be exhibited
Implementation Method 2
molybdenum dithiocarbamate (MoDTC) is added even to a high dispersant-detergent diesel engine oil, and at least one of the sliding members is coated by a titanium nitride-based material
Implementation Method 3
at least one of the sliding members is coated by a titanium nitride-based material (for example, titanium carbon nitride, titanium nitride or titanium nitride aluminum)
Data Source
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AI summary
The purpose of the present invention is to provide: a sliding member having a lubricating film formed on the sliding surface thereof, and capable of exhibiting friction-reducing performance; and a friction reduction method for the same. To that end, the present invention entails coating the sliding surface with a titanium nitride-based material (for example, titanium carbon nitride, titanium nitride, or titanium aluminum nitride), adding a molybdenum dithiocarbamate with molybdenum in the amount of 600-1000ppm to diesel engine oil, setting the arithmetic mean roughness of the sliding member to 2-10nm, and upon converting the Sommerfeld number viscosity to Pa·s, the speed to s-1, and the load to mean Hertzian stress (Pa), then the lubrication conditions for use are within the range of 2.12365×10-19 to 5.94509×10-19.