Aluminum alloy material for forging

A method of manufacturing an aluminum alloy forging material, comprising:

• obtaining 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 by continuously casting a molten aluminum alloy having an aluminum 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 a 5Ti-1B mother alloy, and Ti/Zr ratio satisfies 0.3 or higher;
• obtaining an aluminum alloy cast product by subjecting the aluminum alloy ingot to homogenization treatment for holding the product for one hour or more at temperatures of 450 to 510° C.,
• hot forging the aluminum alloy cast product under temperature conditions of 400 to 510° C.,
• subjecting the aluminum alloy cast product to a solution treatment under temperature conditions of 450 to 510° C., and
• subjecting the aluminum alloy cast product to an aging treatment,
• wherein the aluminum alloy cast product is constituted as the aluminum alloy forging material.