A mold device with a high-temperature, high-pressure, airtight cavity structure, comprising:
- a lower mold, including a lower mold body made of steel, the lower mold body having a main cavity for forming a workpiece, a lower parting surface being defined from the main cavity to a periphery of the lower mold body, the lower parting surface including an inner support surface segment surrounding the main cavity, an outer support surface segment, and an airtight support surface segment between the inner support surface segment and the outer support surface segment, the airtight support surface segment having a plurality of downward concave arc-shaped annular grooves and a plurality of upward convex annular protrusions each connected between every adjacent two of the plurality of downward concave arc-shaped annular grooves;
- an airtight gasket, including a thin gasket body made of a flexible metal material, the thin gasket body surrounding the main cavity of the lower mold and being attached to the lower parting surface, the thin gasket body having an inner gasket lip and an outer gasket lip corresponding to the inner support surface segment and the outer support surface segment, and an airtight gasket frame connected between the inner gasket lip and the outer gasket lip, the airtight gasket frame having a plurality of downward concave annular frame portions that correspond to and are fitted in the respective downward concave arc-shaped annular grooves and a plurality of upward convex annular frame portions each connected between every adjacent two of the plurality of downward concave annular frame portions and being matched with the respective upward convex annular protrusions;
- an upper mold, including an upper mold body made of steel, the upper mold body having an upper cavity, the upper cavity and the main cavity of the lower mold constituting a workpiece forming cavity, an upper parting surface being defined from the upper cavity to a periphery of the upper mold body, the upper parting surface including an inner pressing surface segment surrounding the upper cavity, an outer pressing surface segment, and an airtight pressing surface segment between the inner pressing surface segment and the outer pressing surface segment, the inner pressing surface segment and the outer pressing surface segment being configured for pressing the inner gasket lip and the outer gasket lip of the airtight gasket, the airtight pressing surface segment having a plurality of downward convex annular protrusions configured for pressing the respective downward concave annular frame portions and a plurality of upward concave arc-shaped annular grooves each connected between every adjacent two of the plurality of downward convex annular protrusions and configured for clamping the respective upward convex annular frame portions.