Solar finds impressive results with new sintering vacuum furnace

A Solar Atmospheres retrofitted vacuum furnace has been in production for over a month and has produced multiple high temperature sintering cycles. (Courtesy: Solar Atmospheres of Western PA)

Solar Atmospheres of Western PA has found good results with a retrofitted vacuum furnace for use in a new metal injection molding (MIM) and additive manufacturing (AM) binder removal technology application.

In 2021, the company announced the retrofit of the vacuum furnace. The goal was to build a vacuum sintering furnace with a new innovative hot zone and pumping technology that would minimize and target the deposit of detrimental binders evaporating out of MIM and AM parts. The furnace has now been in production for over a month and has produced multiple high temperature sintering cycles and the results are impressive.

The hot zone, after repeated 2,400°F sintering cycles, remains immaculately clean. The problematic binders coalesced exactly where they were targeted to consolidate — within a separate heated pumping port while keeping the primary pump and booster uncontaminated. Most importantly, the customer reported that their sintered parts processed in this new furnace never looked better. The MIM parts were extremely bright and met their critical density and dimensional requirements.

The anticipated maintenance savings on this dedicated furnace versus processing sintering and AM work with binders in a traditional vacuum furnace will be considerable. Processing this job in a conventional vacuum furnace required a scheduled monthly shutdown. Solar’s maintenance team had to extract the hot zone, replace the ceramics, clean or replace the power feed through terminals, scrape the cold walls, clean the diffusion pumps, and scour all the pumping system pipes. The added labor and material costs coupled with the lost production time and degradation on the life of the hot zone cost the company more than $180,000 per year. The projected maintenance costs on this newly designed sintering furnace will be $10,000 per year.

Bob Hill, president of Solar Atmospheres of Western PA, said, “Knowing the effects of what MIM and certain AM processing had done to our equipment in the past, Bill Jones and the engineers at Solar Manufacturing developed an innovative solution for us. Having this newly designed vacuum furnace will be an asset for our future in MIM and AM processing.”