Apparatus and method for bulk structural modification of metallic materials at reduced temperatures

A monolithic milling vessel with improved cooling capacity, comprising:

• an inner chamber having no welded sections that could permit egress of a refrigerant or coolant into the interior of the vessel;
• and
• an exterior surface having a geometric surface pattern, which includes axial ribs and a series of orifices, specifically designed for heat exchange between the refrigerant or coolant and the milling vessel,
• wherein the ribs are disposed in a divergent channels or parallel radial channels guiding the refrigerant or coolant from at least one entry point to an exit port, and
• the series of orifices are provided at a base of the inner chamber and are configured to allow for the passage of the refrigerant or coolant through a back flange and a motor housing plate to provide cooling to a gear shaft and couplings.