Solar Atmospheres takes advanced technical expertise and equipment and uses it to thermally treat parts in a vacuum environment – serving industries that include aerospace, automotive, defense, medical, and power generation.

Gears and other parts made from metals and metal alloys have to be heat-treated to ensure proper performance, and Solar Atmospheres was born out of that need to offer quality vacuum heat-treating services.

“Generally speaking, we offer vacuum heat treating, which produces clean bright results with limited distortion on most alloys,” said Tim Steber, regional sales manager for Solar Atmospheres. “Specific to gears, we offer vacuum carburizing and vacuum gas nitriding.”

Case-hardening options

Solar Atmospheres offers two different types of case hardening: vacuum carburizing and vacuum gas nitriding.

“Vacuum carburizing is most prevalent for the gear industry, where we basically add carbon to the surface of the product,” he said. “It’s actually a diffusion process, not a coating.”

This process uses high-purity acetylene as the carbon source being diffused into the surface of a material within the vacuum furnace, according to Steber.

“A typical process cycle introduces a ‘boost’ of acetylene into the furnace,” he said. “A dwell time allows the carbon to diffuse into the surface, and the cycle is repeated based on the required carbon content and case depth from the specification.”

Solar Atmospheres uses a thermal-process modeling program to determine the desired case steps, the carbon content, and the amount of time it takes to run a specific process, according to Steber.

“It’s very popular in the aerospace and high-performance racing applications, as well as commercial applications,” he said. “The purpose of carburizing is to increase surface hardness, wear resistance, and fatigue strength.”

In addition to clean, bright results, they emerge from the process with no inter-granular oxidation (IGO), and with uniform case depths, according to Steber. In some cases, no additional finishing is required after carburizing.

Hitachi scanning electron microscope (sem) with energy-dispersive X-ray spectroscopy (EDS). (Courtesy: Solar Atmospheres)

Attending to customers’ needs

Solar Atmospheres takes pride in not only meeting but exceeding its customers’ expectations. no matter the level of heat treating.

Steber said Solar Atmospheres deals with a couple of different types of customers.

“We collaborate with some customers to develop custom heat-treating processes for specific applications,” he said. “We have an in-house tech center with metallurgists and a Ph.D. chemist to assist with the process development. We also partner with customers that have very specific heat-treating process requirements for aerospace and medical applications.”

Using microprocessor controls, Steber said Solar Atmospheres has the capability and expertise to provide consistent, quality results time and time again.

48-foot-long vacuum furnace. (Courtesy: Solar Atmospheres)

Ferrium C61

Solar Atmospheres’ involvement in the gear industry has evolved over the years to include the development of an alloy called Ferrium C61, according to Steber.

“The alloy was in development around 2007,” he said. “Alloy development took approximately five years for this brand-new alloy, which was designed with vacuum carburizing in mind. We were part of the R&D effort and performed hundreds of thermal cycles, including metallography. It became commercially available in 2012. Transcending from our R&D efforts, we designed a furnace specific for vacuum carburizing.”

Ferrium C61 derived from the need in the marketplace for a high-fatigue strength, high-temperature resistant alloy, according to Steber. The Ferrium C61 is used in high-performance automotive and aerospace applications.

Low-torr, high-pressure, quench-carburizing vacuum furnace. (Courtesy: Solar Atmospheres)

Taking on challenges

From that brief resume of accomplishments, it’s obvious that Solar Atmospheres embraces any challenges that customers may throw its way.

Solar Atmospheres purchased a scanning electron microscope (SEM) to meet customers’ expanding needs, according to Steber. The SEM analyzes low level contamination from carbon, oxygen, and/or nitrogen, post heat treating. Additionally, the SEM enables Solar
to fulfill materials characterization and microstructural determination requests beyond the basic metallography and hardness testing.

“We embrace technical challenges related to thermal processing,” he said. “We start with development, perform a risk assessment, and move on from there. The challenge could be anything from one or two pieces that could lead into full production, or it could finish with the one or two pieces. It’s basically a strong suit of our company — problem solving leading to customer satisfaction.”

Nadcap-approved metallurgical laboratory. (Courtesy: Solar Atmospheres)

35 years of expertise

Solar Atmospheres has evolved by leaps and bounds since it began more than 35 years ago, and its impressive inventory and history only solidifies that. The company has the world’s largest commercial vacuum furnaces up to 48 feet long with workloads up to 150,000 pounds. The company’s founder, Bill Jones, has more than 12 patents both on the capital equipment and processing side.

“He really built a foundation for us to follow through on,” Steber said. “Solar Atmospheres started with about four or five furnaces to now having over 60 vacuum furnaces across four locations. We are the largest family-owned vacuum heat treater in the country.”

Cut-section of a carburized gear showing uniform case depth. (Courtesy: Solar Atmospheres)

Looking toward the future

To keep up with the constant development, Steber said the company works five shifts around the clock, 365 days a year. Solar Atmospheres is involved in many high-end aerospace contracts and customers — a testament to the company’s expertise and position in the marketplace.

As Solar Atmospheres continues to move into the future, Steber expects the company to remain involved in alloy developments and solving difficult thermal-processing challenges.