Aluminum Alloy Forging Material for Lightweight Motorcycle Parts
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Solution Overview
Problem
Conventional aluminum alloy forged products, such as those made from JIS 2014 alloy, suffer from insufficient mechanical strength perpendicular to the extrusion direction, leading to tear fractures and increased weight, which is undesirable for lightweight applications like motorcycle parts, and surface treatments like shotblasting deteriorate productivity and increase production costs.
Innovation Solution
An aluminum alloy forging material with a specific composition (Si: 0.80-1.15%, Fe: 0.2-0.5%, Cu: 3.8-5%, Mn: 0.8-1.15%, Mg: 0.5-0.8%, Zr: 0.05-0.13%, and Ti, with a Cu/Mg ratio of 8 or less, is subjected to homogenization treatment and hot forging, followed by solution treatment under controlled temperature conditions to enhance strength and surface color tone while reducing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional JIS 2014 alloy is used for forging, then the forged product exhibits high stretching properties in the extrusion direction, but the mechanical strength is insufficient and tearing occurs in the perpendicular direction
Solution Approach 1:
The patent applies parameter changes by precisely controlling the alloy composition parameters (Si: 0.80-1.15%, Fe: 0.20-0.50%, Cu: 3.80-5.00%, Mn: 0.80-1.15%, Mg: 0.50-0.80%, Zr: 0.05-0.13%, Ti: 0.02-0.05%) and processing parameters (homogenization temperature 450-510°C, forging temperature 400-510°C) to achieve both high strength and tear resistance without requiring design compensations
2Shape
If surface treatment such as shotblasting is performed to erase macro patterns, then the surface appearance is improved, but productivity deteriorates and production cost increases
Solution Approach 1:
The patent applies preliminary action by controlling the microstructure parameters (secondary dendrite arm spacing ≤40μm, average crystal grain diameter ≤8μm) and performing homogenization treatment before forging to prevent macro pattern formation in the first place, thereby eliminating the need for subsequent surface treatment operations
Solution Approach 2:
The patent converts the potentially harmful effect of acid cleaning (which causes macro patterns) into a benefit by precisely controlling the microstructure parameters so that even after acid cleaning, no macro patterns appear on the surface, eliminating the need for corrective surface treatment
3Reliability
If the dimension in the perpendicular direction is increased to prevent tear fracture, then the strength and reliability are improved, but the weight increases
Solution Approach 1:
The patent applies parameter changes by optimizing the alloy composition (particularly Cu: 3.80-5.00%, Mn: 0.80-1.15%, Mg: 0.50-0.80%) and processing parameters to achieve superior mechanical properties, allowing the use of smaller dimensions while maintaining or improving tear fracture resistance, thereby reducing weight
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 approach results in forged products with improved mechanical strength, reduced weight, and enhanced surface color tone, while also improving production efficiency and reducing costs by minimizing the need for surface treatments like shotblasting.
Implementation Method 1
subjecting an aluminum alloy ingot having a structure in which a secondary dentrite arm spacing (DAS) is 40 μm or less and an average crystal grain diameter of crystallized substances is 8 μm or less to homogenization treatment for holding the ingot for one hour or more under temperature conditions of 450 to 510° C.
Implementation Method 2
homogenization treatment for holding the ingot for one hour or more under temperature conditions of 450 to 510° C.
Implementation Method 3
subjecting the aluminum alloy forging material to hot forging under temperature conditions of 400 to 510° C.
Implementation Method 4
hot forging under temperature conditions of 400 to 510° C.
Implementation Method 5
further subjecting the aluminum alloy forging material to solution treatment under temperature conditions of 450 to 510° C.
Data Source
AI summary
An aluminum alloy forging material of the present invention is constituted by an aluminum alloy cast product obtained by subjecting an aluminum alloy ingot having a structure in which a secondary dentrite arm spacing (DAS) is 40 μm or less and an average grain diameter of crystallized substances is 8 μm or less to homogenization treatment for holding the ingot for one hour or more under temperature conditions of 450 to 510° C., wherein the ingot is obtained by continuously casting a molten aluminum alloy having an alloy composition consisting of: Si: 0.80 to 1.15 mass %; Fe: 0.2 to 0.5 mass %; Cu: 3.8 to 5 mass %; Mn: 0.8 to 1.15 mass %; Mg: 0.5 to 0.8 mass %; Zr: 0.05 to 0.13 mass %; and Ti contained in such an amount that a sum of Ti and Zr is 0.2 mass % or less, and the balance being Al and inevitable impurities, wherein the alloy composition satisfies a Cu/Mg ratio of 8 or less, Ti is added in a form of an Al master alloy (5Ti-1B mother alloy) in which Ti and B are contained at a ratio of 5:1, and a Ti/Zr ratio satisfies 0.3 or higher.