Cu-Mg-P Alloy Microstructure for Connector Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current materials like brass and phosphor bronze used for connectors and terminal components in electronic and automotive applications lack sufficient strength, elasticity, conductivity, and resistance to migration issues, making them inadequate for miniaturized and high-current applications.
Innovation Solution
A Cu—Mg—P based copper alloy with a specific composition and microstructural characteristics, including an area fraction of crystal grains with an average misorientation less than 4°, is developed, along with a production process involving hot rolling, solution treatment, and low-temperature annealing, to achieve balanced tensile strength and bending elastic limit values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If brass is used as connector material, then ease of manufacture is improved, but strength and conductivity are insufficient
Solution Approach 1:
The patent uses a composite copper alloy material containing Cu, Mg, and P elements. The specific composition (Cu: balance, Mg: 0.01-2.0 wt%, P: 0.003-0.05 wt%) creates a multi-phase microstructure that combines the advantages of different elements to achieve both high strength and good manufacturability.
Solution Approach 2:
The patent changes the chemical composition parameters by adding specific amounts of Mg and P elements to the copper base. This parameter modification transforms the material properties to achieve the desired balance between strength and ease of manufacture.
2Strength
If phosphor bronze is used as connector material, then strength and elasticity are improved, but conductivity deteriorates
Solution Approach 1:
The patent precisely controls the composition parameters, limiting P content to 0.003-0.05 wt% and Mg content to 0.01-2.0 wt%. This parameter optimization maintains high conductivity while achieving the required strength level.
Solution Approach 2:
The patent creates local microstructural features through controlled rolling processes that produce specific grain shapes and sizes. This local microstructural optimization provides strength enhancement without compromising the overall conductivity of the material.
3Length of moving object
If material thickness is reduced for miniaturization, then connector size is reduced, but bending elastic limit value deteriorates
Solution Approach 1:
The patent applies specific rolling reduction ratios (30-85% in final cold rolling) and controls crystal grain dimensions (5-20 μm average diameter) to enhance the bending elastic limit value, enabling thin materials to maintain high strength.
Solution Approach 2:
The patent performs preliminary crystal grain control through controlled rolling processes before final connector formation. This preliminary microstructural preparation ensures that even thin materials possess the necessary bending elastic limit value.
4Length of moving object
If connector pitch is reduced for miniaturization, then connector size is reduced, but migration resistance deteriorates
Solution Approach 1:
The patent converts the potential harm of reduced pitch into a benefit by using controlled crystal grain structures that actively prevent migration. The specific grain morphology and size distribution created through rolling processes form barriers against ion migration even at narrow pitches.
Solution Approach 2:
The multi-element copper alloy composition creates a complex microstructure that provides inherent migration resistance. The interaction between Cu, Mg, and P phases forms a protective microstructural barrier against electrochemical migration.
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 Cu—Mg—P alloy exhibits high tensile strength (641 to 708 N/mm²) and bending elastic limit values (472 to 503 N/mm²), effectively addressing the limitations of existing materials and ensuring reliable performance under stress and varying environmental conditions.
Implementation Method 1
a hot rolling starting temperature is 700° C. to 800° C., a total hot rolling reduction ratio is 90% or higher
Implementation Method 2
solution treatment, finishing cold rolling, and low temperature annealing in this order
Implementation Method 3
the low temperature annealing is performed at 250° C. to 450° C. for 30 to 180 seconds
Data Source
AI summary
A copper alloy material includes, by mass %, Mg of 0.3 to 2%, P of 0.001 to 0.1%, and the balance including Cu and inevitable impurities. An area fraction of such crystal grains that an average misorientation between all the pixels in each crystal grain is less than 4° is 45 to 55% of a measured area, when orientations of all the pixels in the measured area of the surface of the copper alloy material are measured by an EBSD method with a scanning electron microscope of an electron backscattered diffraction image system and a boundary in which a misorientation between adjacent pixels is 5° or more is considered as a crystal grain boundary, and a tensile strength is 641 to 708 N/mm2, and a bending elastic limit value is 472 to 503 N/mm2.