Resources

A Vacuum Gauge is a pressure measuring instrument that measures pressure in a vacuum (i.e., in a vessel operating at sub-atmospheric pressure). Depending on the type of vacuum system (Fig. 1) and the required operating vacuum level, different vacuum gauges[...]

Vacuum valves are an essential component in any vacuum system. There are a variety of different types that fall into three main categories – operational valves, closing valves and sealing valves (Fig. 1). The selection of the proper valve type[...]

Passing a Nadcap audit is considered by most heat treaters to be both a significant company-wide accomplishment and a benchmark as to their commitment to quality. Nadcap accreditation not only allows the company to perform heat treating for the Aerospace/Defense[...]

When problems arise, especially those related to safety, we want to know that we have isolated the root cause and instituted corrective action measures so as to avoid their reoccurrence. Worker safety and the safe operation of heat-treat equipment is both[...]

For those of us who participate in the Heat Treatment group of LinkedIn (https://www.linkedin.com/groups/1855932), which by the way is 8795 members strong (!), an important vacuum processing question was recently asked and what follows is a stimulating exchange of ideas,[...]

Many of us who use vacuum furnaces are all too familiar with and have learned how to counteract the unintentional diffusion bonding that has been known to occur between component parts exposed to high temperatures and low vacuum levels.1 By contrast,[...]

When performing any type of vacuum heat treatment it is always important to be aware of the possibility of evaporation and/or sublimation of elements, which can be present in the material being processed, introduced into the vacuum system with the[...]

Vacuum deposition is a generic term used to describe a type of surface engineering treatment used to deposit layers of material onto a substrate. The types of coatings include metals (e.g., cadmium, chromium, copper, nickel, titanium) and nonmetals (e.g., ceramic[...]

The movement of gases is an important and interesting subject but one often dismissed as a topic best left to scientists. However, the Heat Treater needs to know something about the basic nature (theory) of gases and in particular how[...]

Since brazing plays an important part in some of your company’s products, plan to have one or more of your people attend one of the high-powered, three-day (Tues-Thurs) seminars being held in 2020. Contact your people today to have them[...]

Shell & tube heat exchangers (S&THE) have been used for many years in a wide range of industries, including aerospace, oil refineries, chemical processing, beverage industries, and pharmaceutical industries, to name a few. Brazing has become more and more the desired[...]

Braze-spatter is occasionally seen in furnace brazing and usually occurs when someone is using brazing paste. I have not personally seen it happen when solid forms of brazing filler metal (BFM) such as wire, sheet or solid rings are used.[...]

One of the most widely used charts in the field of brazing is the strength vs. clearance chart created from work done in the Handy & Harman laboratories in Fairfield, Connecticut back in the 1930's. This chart is shown below,[...]

Earlier this year, I wrote an article on this website about the use of Zinc (Zn) in brazing, and strongly warned readers to never vacuum-braze any metals/alloys that contained any Zn in their chemistry or if they had Zn-plating on[...]

Oil sealed rotary vane pumps (aka rotary vane pumps) are the primary pumps on most vacuum systems used in the heat treatment industry. They are also referred to as a "backing" pump when used in combination with a booster pump,[...]

Selecting the correct vacuum gauge or gauges is critical to the success of a heat treatment process. It is important to know how they work and what options are available so that the correct choice can be made. There are[...]

Dry pumps are becoming increasingly popular as an alternative to oil sealed rotary vane pumps for many medium and high vacuum applications (e.g., in low-pressure vacuum carburizing where fine granular soot is carried from the process into the pump). Designers[...]

The Edwards “RV” (simply meaning Rotary Vane) laboratory sized oil sealed rotary vane vacuum pumps (Fig. 1) have been in the market for 25 years. They have a very unique design with no equal. This article will attempt to show[...]

Vee belt drive design This article discusses one and two-stage “medium vacuum” oil sealed rotary vane vacuum pumps that can produce a catalog ultimate vacuum of about 1 x 10-2 Torr (0.01 Torr or 10 microns) for a one stage model[...]

Abstract Meteorites have fascinated mankind for centuries. Indeed, more than two dozen meteorites have been venerated by Indian tribes, aborigines, Arabs and other ancient peoples. The study of meteorites is part of the overall study of the origin of our solar[...]

Introduction The microstructure of iron-based alloys is very complicated, being influenced by composition, homogeneity, processing and section size. Microstructures in coarse-grained steels are much easier to observe than in fine-grained steels. Of course, steels are normally made with a fine grain[...]

Failures in metallic components may be caused by any of the following factors or combinations of factors: Design shortcomings Imperfections due to faulty processing or fabrication Overloading and other service abuses Improper maintenance and repair Environmental factors Not all failures are[...]

Abstract Tool Steel Failure Examples and Metallographic Imagery below. Steels used for tools and dies differ from most other steels in several aspects. First, they are used in the manufacture of other products by a variety of forming processes. Second, tools and[...]

Abstract Medical technology has developed many new devices that can be implanted into humans (in-vivo) to repair, assist or take the place of diseased or defective bones, arteries and even organs. The materials used for these devices have evolved steadily over[...]