Plain-Bearing Composite Material Hardening by Direct Quench Aging
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Solution Overview
Problem
Existing methods for producing plain bearing composite materials do not meet the increased requirements for strength, as they are time-consuming and costly, and the resulting materials lack the necessary mechanical properties such as tensile strength, yield strength, and hardness.
Innovation Solution
A method that involves sintering a copper alloy powder onto a steel strip, followed by rapid quenching and aging without an annealing step, allowing for the adjustment of mechanical properties through the quenching and aging process, which includes quenching for less than two minutes and aging at temperatures between 350°C to 520°C for four to ten hours.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If annealing is performed after sintering to dissolve precipitates and create a uniform structure, then homogeneity is improved, but production time increases and the process becomes more complex
Solution Approach 1:
The patent removes the annealing step from the conventional heat treatment process after sintering. By extracting this intermediate homogenization step, the process achieves the desired uniform structure directly through controlled quenching and aging, significantly reducing production time while maintaining compositional homogeneity through the supersaturated solid solution mechanism.
Solution Approach 2:
The patent skips the conventional annealing step by rapidly quenching the sintered composite material from sintering temperature to room temperature or below. This rapid cooling bypasses the slow diffusion-based homogenization of annealing and directly creates a supersaturated solid solution that subsequently ages to achieve uniform structure, thereby rushing through the homogenization process in minutes rather than hours.
2Strength
If conventional heat treatment including annealing and quenching is used, then mechanical properties are improved, but the process becomes more complex and costly
Solution Approach 1:
The patent merges the annealing and quenching steps into a single integrated heat treatment process. The sintering operation itself provides the necessary heating, followed by direct quenching, eliminating the need for separate annealing equipment and operations. This consolidation maintains mechanical property enhancement while simplifying the overall process flow and reducing equipment complexity.
Solution Approach 2:
The sintering process is given multiple functions: it serves both as the consolidation operation for the copper powder and as the heating step that prepares the material for quenching. This multi-functionality eliminates the need for a dedicated annealing step, reducing process complexity and cost while achieving the same microstructural preparation for subsequent aging hardening.
3Productivity
If rapid quenching is performed after sintering, then production time is reduced and hardness is improved, but the process requires precise temperature control
Solution Approach 1:
The sintering process is designed to reach and maintain a specific temperature range (800-1100°C) before quenching begins. This preliminary heating ensures the material is properly prepared for rapid cooling, with the copper powder fully densified and the steel substrate in the appropriate thermal state. By pre-establishing these conditions, the subsequent quenching can proceed rapidly with more forgiving temperature control requirements.
Solution Approach 2:
The patent utilizes the phase transformation characteristics of steel at different cooling rates from the sintering temperature. By changing the cooling rate parameter during quenching, the process achieves desired microstructural transformations without requiring extremely precise temperature control throughout the entire process. The inherent phase diagram properties of the steel-copper system provide natural guidance for the transformation process.
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 method significantly improves the mechanical properties of the composite material, achieving higher strength, hardness, and electrical conductivity, making it suitable for heavy-duty applications such as in trucks and industrial machinery.
Implementation Method 1
a powder of a bearing metal is applied to a strip material made of steel, the bearing metal is subjected to at least one sintering process
Implementation Method 2
the composite material is quenched and then an aging process is followed
Implementation Method 3
an aging process is followed... aging at temperatures between 350°C to 520°C for four to ten hours
Implementation Method 4
precipitation hardening (aging)... cause segregation and/or precipitation from supersaturated mixed crystals
Data Source
Figure 1~2
Figure 3
Figure 4a~4b
AI summary
Disclosed is a method for producing plain-bearing composite materials (30), in which a powder (11) of a bearing metal is applied to a strip material (6) consisting of steel and the bearing metal undergoes at least one sintering process. The composite material (25) consisting of the strip material (6) and the bearing metal (14) subsequently undergoes a heat treatment. After the sintering process the composite material (25) is quenched, directly followed by an ageing process. The plain-bearing composite material (30) has a substrate (32) consisting of steel and a sintered bearing metal layer (34) consisting of a copper alloy, the bearing metal layer (34) having a hardness of 100 HBW 1/5/30 to 200 HBW 1/5/30.