Experience has shown us that sensitive materials in the presence of minute quantities of unwanted gaseous contaminates can destroy the integrity and shorten the life expectance of components.

It is natural to ask ourselves what can be done to further protect the work in a vacuum environment after the pumps have done their part in reducing the chamber pressure to as low as is economically feasible in a production environment? This task falls to getter materials. By Dan Herring

The 27th part in our Vacuum Heat-Treatment Series focuses on vacuum markets, new technology trends and future direction.

The last decade has seen double-digit growth in the use of vacuum heat treating and an increased vacuum market share throughout the Americas. Vacuum processing is growing more rapidly than any other technology, due in large part to the demand for high-quality, precision processes and repeatability of part performance in ever more sophisticated and demanding service applications. By Dan Herring

This article, the 26th in our Vacuum Heat-Treatment Series, focuses on applications involving less common or special vacuum processes.

In this part, we focus on examples of certain standard and special processes run every day in vacuum equipment. The types of materials, products and processes vary depending on the needs of the industry being serviced, but they all take advantage of vacuum’s unique ability with respect to quality and repeatability of cycles and results. By Dan Herring

Next time: We will discuss the potential for vacuum heat treating and vacuum metallurgy by looking at the markets, technology trends and future role of vacuum in the heat-treating industry.

This is the 24th article in our Vacuum Heat-Treatment Series, and it focuses on applications involving vacuum brazing. Brazing is a joining operation, and it is well-suited for vacuum processing since it involves a variety of base metal materials and filler metal alloys.

Vacuum brazing represents one of the largest application uses for vacuum furnaces. The transportation industry (automotive and aerospace) in particular has provided the impetus for increasing demand for vacuum brazing. In addition, the gain in popularity of lightweight, high-strength materials has also contributed to the popularity of vacuum brazing. By Dan Herring

This is the 23rd article in our Vacuum Heat-Treatment Series. It focuses on applications involving the hardening of steels in vacuum.

In general, applications involving vacuum heat treating can be broken down into four main categories: Processes that can be done in no other way than in vacuum, processes that can be done better in vacuum from a metallurgical standpoint, processes that can be done better in vacuum from an economic viewpoint, processes that can be done better in vacuum from a surface finish perspective. By Dan Herring

Next Time: Part 24 of this series continues our discussion of the various heat-treatment applications by talking about vacuum brazing.

This is the 22nd in our Vacuum Heat-Treatment Series. Selecting the proper backfill gas and backfill system is a key aspect in proper operation of any vacuum system, whether it be for a partial-pressure atmosphere, a process gas, a quench gas or a gas used to equalize pressure between chambers for load transfer or removal.

Backfill Gases: The most common gases used in vacuum processing are nitrogen, argon, helium and hydrogen (Tables 1-4). Other common specialty gases include various hydrocarbons and ammonia (for vacuum carburizing/carbonitriding) and carbon dioxide. Each of these gases and how they are used will be discussed. By Dan Herring

Next Time: Part 23 of this series begins a discussion of the various heat-treatment applications commonly run in vacuum. We start by considering vacuum hardening.

This is the 21st article in our Vacuum Heat-Treatment Series. Grids, baskets and fixtures for use in vacuum applications are made from materials such as high-temperature metallic alloys, graphite, ceramic-fiber composite (CFC) materials or combination designs utilizing multiple materials. Proper design and material selection will maximize useful life and allow a true cost/benefit analysis to be performed.

Our mission is to provide an overview of some of the basic requirements necessary for selection of material systems for use in thermal-processing applications running from subzero temperatures as low as -195ºC (- 320ºF) to elevated temperatures as high as 1650ºC (3000ºF) and beyond. This information is presented for the purpose of aiding in the selection process for those who have not had the opportunity to work with these materials in great detail. By Dan Herring

Next Time: We will talk about selecting the proper backfill gas and backfill system, whether it be a partial-pressure atmosphere, a process gas, a quench gas or a gas used to equalize pressure between chambers for load transfer or removal.