Multilayer Sintered Plate Alloy for Sulfidation-Resistant Sliding
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Solution Overview
Problem
Bronze-based copper alloy porous sintered layers in multilayered sliding members are prone to sulfidation corrosion when used in lubricating oils containing extreme pressure additives like sulfur, leading to reduced strength and increased wear.
Innovation Solution
A multilayered sintered plate with a porous sintered alloy layer composed of 30-50% nickel, 1-10% phosphorus, and 2.5-10% tin, featuring a matrix phase with an iron-nickel-tin alloy and a hard phase with a nickel-phosphorus-iron-tin alloy, which is sintered onto a backing plate, providing enhanced wear resistance and preventing sulfidation corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bronze-based copper alloy porous sintered layer is used in a multilayered sliding member, then firm bonding strength and excellent sliding characteristics are achieved, but sulfidation corrosion occurs when used in lubricating oils containing extreme pressure additives like sulfur
Solution Approach 1:
The invention changes the chemical composition parameters of the porous sintered alloy layer by adding tin (2-10 mass%) to the bronze-based copper alloy. This parameter change modifies the material's chemical properties to resist sulfidation corrosion from sulfur-containing lubricating oils while maintaining the original sliding characteristics and bonding strength.
Solution Approach 2:
The invention creates a composite material system by combining multiple elements (copper, tin, phosphorus, and optionally zinc and lead) in a porous sintered structure. This composite approach integrates the beneficial properties of each element: copper provides ductility and bonding, tin provides corrosion resistance, phosphorus provides wear resistance, and the porous structure provides oil retention and lubrication.
2Reliability
If sulfur-containing extreme pressure additives are added to lubricating oil to improve seizure resistance, then seizure resistance is enhanced, but sulfidation corrosion occurs in the copper-based porous sintered alloy layer
Solution Approach 1:
The invention converts the harmful effect of sulfur (which causes sulfidation corrosion in copper) into a beneficial situation by adding tin to the alloy. The tin preferentially reacts with sulfur to form tin sulfides, protecting the copper from sulfidation. This allows the use of sulfur-containing extreme pressure additives for their intended purpose of improving seizure resistance without suffering from sulfidation corrosion.
3Strength
If phosphorus, aluminum, or bismuth are added to the porous sintered alloy layer to improve wear resistance, then wear resistance is enhanced, but the susceptibility to sulfidation corrosion from sulfur-containing lubricating oils increases
Solution Approach 1:
The invention changes the compositional parameters by adding tin (2-10 mass%) to the alloy system containing phosphorus, aluminum, or bismuth. This parameter modification enables the material to maintain the wear resistance benefits of these additives while gaining protection against sulfidation corrosion from sulfur-containing lubricating oils.
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
The solution significantly improves wear resistance and prevents sulfidation corrosion even in lubricating oils with extreme pressure additives, maintaining excellent sliding characteristics and extending the lifespan of the multilayered sliding member.
Implementation Method 1
a porous sintered alloy layer which is integrally joined to one surface of the backing plate
Implementation Method 2
a structure which includes a matrix phase containing an iron-nickel-tin alloy and a hard phase precipitated in the matrix phase and containing a nickel-phosphorus-iron-tin alloy
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A manufacturing apparatus 1 has a leveler 3 which, while pulling out a steel plate starting with one end thereof and while transporting it, corrects the waviness and the like of the steel plate, which serves as a backing plate 2 and is constituted by a continuous strip having a thickness of 0.3 to 2.0 mm and provided as a hoop material by being wound into a coil shape.