New Large-Capacity Vacuum Hot Press Design

Solar Manufacturing installed and started-up a 100-ton force vacuum hot press at Refrac Systems in Chandler, AZ, a system that includes a 2-bar gas fan quench cooling system (GFQVHP.)

The hot pressing process uses vacuum pressure to diffusion-bond, braze, or sinter components om a reducing atmosphere (thereby removing surface oxides) before pressing the parts together under a high, uniaxial ram load. It is possible to assemble parts with very small internal passage geometries, such as micro-fluidic controls or high convective heat-transfer heat exchangers with no damage to the internal passages.

Refrac Systems offers commercial heat-treating and diffusion bonding, particularly for aerospace manufacturers. It also offers brazing and hot pressing, with projects that have included aircraft engine parts and final component fabrication. Some of projects have included booster-rocket instruments for the NASA Space Shuttle, internal cooling passages for injection-molded blanks, copper heat-transfer systems for high-power lasers, and titanium and stainless steel hydraulic control components for robot arms.

Solar Manufacturing designs and manufactures vacuum heat-treating, sintering, and brazing furnaces. Its engineers worked with Refrac Systems on a version of the standard HLF-5748-2IQ internally quenched 2-bar vacuum furnace as the base design.

The furnace hot zone was modified to contain a 100-ton load hydraulic ram centered over the zone, which is configured to diffusion-bond parts up to 36x48x30 in. (WxLxH.)  

In addition to being specifically designed to diffusion-bond large plastic injection molding dies, and concurrently quench hardening them, Refrac’s new hot press system will be avaialbe for applications in bonding advanced superalloy heat exchangers where the quench cooling offers significant improvement on performance.

“We really drew on the extensive engineering experience base that Solar Manufacturing has for building large, gas -fan quench-cooled vacuum furnaces, coupled with our own vacuum hot-pressing experience, to build this very unique hot press system,” noted Norm Hubele, Refrac Systems president.

Hubele also credited Solar’s engineering team for devising several complex, new engineering solutions that reduce the operational and ownership risks of the new furnace system.