Bi-Containing Copper Slide Material With Stronger Substrate Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The bonding strength between a copper alloy layer with Bi phases and a substrate is compromised due to Bi accumulation at the bonding interface during the sintering process, leading to reduced material strength, especially under increased loads or in downsized engine applications.
Innovation Solution
A method involving a copper alloy layer with Bi phases dispersed in a copper alloy matrix, where the contact area ratio of Bi phases at the bonding interface is minimized through unidirectional solidification and controlled cooling, ensuring a reduced Bi presence at the interface and enhanced bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Bi is added to copper alloy to improve seizure resistance, then seizure resistance is improved, but Bi accumulates at the bonding interface during sintering, reducing bonding strength between copper alloy layer and substrate
Solution Approach 1:
The patent applies parameter changes by controlling the particle size distribution of Bi phases, specifically setting the average particle size to 2-50 μm with circularity of 0.1-0.7. This parameter control prevents Bi accumulation at the bonding interface during sintering while maintaining sufficient Bi content (5-30 mass%) in the copper alloy layer for seizure resistance.
Solution Approach 2:
The patent applies local quality by creating a non-uniform distribution of Bi phases where particles are dispersed in the copper alloy matrix but excluded from the bonding interface region. This local differentiation ensures that the bonding interface has high Cu content for strong bonding, while the bulk material contains Bi phases for seizure resistance.
2Reliability
If Bi content in copper alloy layer is increased to improve seizure resistance, then seizure resistance is improved, but bonding area between copper alloy and substrate decreases, reducing overall material strength
Solution Approach 1:
The patent applies parameter changes by specifying that Bi particles with circularity of 0.1-0.7 and size of 2-50 μm should constitute 30% or more of total Bi phases. This controlled morphology and size distribution ensures Bi phases remain dispersed in the matrix without coalescing at the bonding interface, maintaining both high Bi content for seizure resistance and sufficient bonding area.
Solution Approach 2:
The patent applies composite materials by creating a heterogeneous structure where Bi phases are dispersed as distinct particles within the copper alloy matrix. This composite structure allows the Cu matrix to provide bonding area at the interface while Bi particles provide seizure resistance in the bulk, with the interface region being predominantly Cu-rich.
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 increases the bonding area and strength between the copper alloy layer and the substrate, improving the overall material strength and reducing manufacturing costs by minimizing Bi phases at the bonding interface.
Implementation Method 1
Bi is melted during a temperature rise in a first sintering step
Implementation Method 2
the molten Bi starts to flow before copper alloy particles are bonded to each other. A part of Bi melted at an early stage during the first sintering step flows down to an interface between the copper alloy powder and the substrate through a gap between the copper alloy particles
Implementation Method 3
Such a sliding material including a copper alloy including Bi is manufactured by sintering a copper alloy powder scattered on a substrate
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Provided are a slide material in which the joining strength between a Bi-containing copper alloy layer and a substrate is improved, and a method for manufacturing the slide material. The slide material according to the present invention has a substrate and a copper alloy layer. The copper alloy layer comprises a copper alloy containing 4.0-25.0 mass% of Bi and has a structure in which Bi phases are scattered in a copper alloy structure. The contact area ratio of Bi phases of the copper alloy layer at the joining interface with the substrate is not more than 2.0%. The slide material is manufactured by casting a molten copper alloy onto a substrate and causing the copper alloy to solidify unidirectionally.