ONLINE EXCLUSIVE- Case Study: New Furnace Shows Promise at PSU

A new ultra-high-temperature, ultra-low-oxygen thermal processing furnace installed at The Pennsylvania State University is providing positive results in a range of industrial applications

Figure 1. Free energy of metallic oxide formation and the zone of the furnace operation.
A new continuous furnace* capable of heating to 2200°C has been installed at the Center for Innovative Sintered Products (CSP) at The Pennsylvania State University (PSU) in University Park, Pa. The furnace allows metals and alloys to be sintered and brazed at a reduced oxygen partial pressure without the use of vacuum or hydrogen. This is particularly desirable for sintering and brazing materials with high-vapor-pressure elements, such as chromium and manganese.

Unlike traditional sintering furnaces, where reduction is provided by either hydrogen gas or carbon monoxide, the operation of the new furnace is based on the technology of metal refining, as described by the Ellingham or Richardson Diagram. Figure 1 shows the relationship between metals and metal oxides and their relative stability. As the partial pressure of oxygen is reduced, the ability for heat dissociation of oxides becomes greater.

In vacuum processing, applying a vacuum reduces the partial pressure of oxygen; however, this can result in the evaporation of high-vapor-pressure metals. The new furnace works by reducing the partial pressure of oxygen within the furnace-not by vacuum, but rather by the oxidation of the graphite within the furnace. The graphite essentially acts as a "getter" for any residual oxygen that is present in the process gas. From a physical chemistry standpoint:

C + ? O2 ?CO

The low-oxygen atmosphere will thus reduce even difficult-to-reduce oxides, such as MnO, SiO2, and TiO2, without evaporation.

*The KYK Oxynon(r) sintering furnace, supplied by Kanto Yakin Kogyo, Hiratsuka, Kanagawa, Japan.

A CISP researcher sets up the gas flow on the new furnace.
Test results from the new furnace to date have been positive. For instance, titanium has successfully been sintered continuously with an elongation of 15%, and superalloys have been successfully brazed. Additionally, manganese-containing braze has been used to sinter-braze powder metal components with good bond strength.

Many other materials-including tungsten carbide, niobium, molybdenum, tungsten, silicon nitride and alumina-have also been evaluated in the furnace and are still under development, but the results are expected to be equally positive.

Furnace Features

* Operating temperature: 2200°C (3992°F)

* Number of hot zones: four

* Belt type: graphite composite

* Opening size: 10 in. wide x 4 in. high

* Gases: nitrogen, argon and potentially helium



For more information about the new furnace or to arrange an evaluation of its performance in a specific application, contact CISP at (814) 865-7346 or e-mail dfh100@psu.edu . More information about the furnace can also be found at http://www.oxynon.com .

Did you enjoy this article? Click here to subscribe to Ceramic Industry Magazine.

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

November 2014 Issue Highlights

Our November 2014 issue is now available! Posted: March 31, 2015.

Podcasts

Ceramics Expo podcast
Editor Susan Sutton discusses the upcoming Ceramics Expo with event director Adam Moore.
More Podcasts

Ceramic Industry Magazine

CI April 2015 edition

2015 April

You'll want to check out our continuing coverage of the inaugural Ceramics Expo event, plus articles on dental ceramics, glass coatings, refractories, and more!

Table Of Contents Subscribe

Daily News

We know where you find the latest ceramic industry news (ahem), but where do you catch up on the rest of your daily news?
View Results Poll Archive

THE CERAMIC INDUSTRY STORE

M:\General Shared\__AEC Store Katie Z\AEC Store\Images\Ceramics Industry\handbook of advanced ceramics.gif
Handbook of Advanced Ceramics Machining

Ceramics, with their unique properties and diverse applications, hold the potential to revolutionize many industries, including automotive and semiconductors.

More Products

Clear Seas Research

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications,Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

STAY CONNECTED

facebook_40px twitter_40px  youtube_40pxlinkedin_40google+ icon 40px

Directories

CI Data Book July 2012

Ceramic Industry's Directories including Components, Equipment Digest, Services, Data Book & Buyers Guide, Materials Handbook and much more!