Frame member for use in two-wheeled vehicle and all-terrain vehicle, and method for producing the same

A frame member for use in a two-wheeled vehicle and an all-terrain vehicle, comprising a plurality of Al members each formed of a 7000 series Al alloy consisting of Cu:

• 0.01 to 0.50%, Mg:
• 0.5 to 2.1%, and Zn:
• 4.0 to 8.5% on a mass basis, the balance being Al and inevitable impurities, the plurality of Al members being integrated by welding and subjected to one of a T4 treatment and a T6 treatment,
• wherein the plurality of Al members are integrally connected by means of a weld joint formed by welding using a filler metal consisting of Mg:
• 5.5 to 8.0%, Mn:
• 0.05 to 1.0%, Cr:
• 0.05 to 0.25%, Ti:
• 0.25% or less, Si:
• 0.4% or less, Fe:
• 0.4% or less, Cu:
• 0.1% or less, Zr:
• 0.05% or less and Zn:
• 0.25% or less on a mass basis, the balance being Al and inevitable impurities.

A method of producing a frame member for use in a two-wheeled vehicle and an all-terrain vehicle, comprising the steps of:

• welding a plurality of Al members each formed of a 7000 series Al alloy by using a filler metal to prepare a joined product, the 7000 series Al alloy consisting of Cu:
• 0.01 to 0.50%, Mg:
• 0.5 to 2.1%, and Zn:
• 4.0 to 8.5% on a mass basis, the balance being Al and inevitable impurities, and the filler metal consisting of Mg:
• 5.5 to 8.0%, Cr:
• 0.05 to 0.25%, Ti:
• 0.25% or less, Si:
• 0.4% or less, Fe:
• 0.4% or less, Cu:
• 0.1% or less, Zr:
• 0.05% or less and Zn:
• 0.25% or less on a mass basis, the balance being Al and inevitable impurities, and
• performing one of a T4 treatment and a T6 treatment on the joined product.