Resources

The demands on space simulation chambers from the extremes of temperature and vacuum were discussed in Part One along with the development of space simulation chambers (aka space simulators) for testing of components used on vehicles for space travel suchRead more...

Finding leaks in vacuum furnaces is a task that few of us cherish but all of us know is important and necessary. Leaks are a problem experienced by almost every vacuum user. Leaks can occur suddenly or develop slowly overRead more...

HOT-ZONE CONSTRUCTION Hot-zone service life is directly related to the type of heat treating process used in a vacuum furnace and to the severe thermal stresses imposed by continuous vacuum-furnace cycles. For example, a by-product of high-temperature sintering is contamination inRead more...

Manufacturers of materials, components, and machines for spacecraft and satellites deployed in space must vigorously test them prior to putting them into service. For example, linear actuator mechanisms on satellites have failed to function properly (extend or retract) because ofRead more...

We continue our discussion from Part One on the vacuum vapor degreasing method by focusing on the subject of part drying. Drying in Aqueous Systems In aqueous systems, heated air-drying is the most common method used for water removal. However, itRead more...

Cleaning in a solvent offers a level of simplicity and forgiveness not seen in aqueous methods. At one time solvent cleaning was considered mandatory for successful vacuum processing but environmental concerns (VOC and other emissions) and improvements to aqueous systemsRead more...

In parts 1 and 2 we talked about the Kinetic Theory of Gases and in particular, we showed how the movement of atoms affects principles such as molecular density, mean free path, and molecular velocity and how they are usedRead more...

Last time (The Fundamentals of Vacuum Theory – Part 1) we talked about the Kinetic Theory of Gases and how it can be used to calculate gas properties. We also considered the relationship between molecular density, mean free path, molecularRead more...

As in any discipline, understanding the underlying scientific principles has profound practical implications when properly understood. In this series of articles we will review the first principles of vacuum technology and explain them using real world illustrations. Most industrial vacuum systemsRead more...

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 2017. Contact your people today to have themRead more...

We return this month to our series on the essential criteria for brazing, to complete our current series on some fundamental issues about brazing filler metals (BFMs). As was discussed in my previous article on Essential Criteria for Brazing, ifRead more...

This quiz was not as easy as many of you may have thought. I chose a number of questions that I knew would “challenge” many of you to more clearly think about some of the principles of brazing, and howRead more...

IMPORTANT NOTE: The Brazing Quiz published in our April column is STILL open for readers to try. Because only a few people actually sent in their replies, we encourage more of you to do so. We’ll then publish the answersRead more...

For this month’s column we would like to challenge our readers to have some fun with a brazing quiz. If you would like to try our Brazing Quiz, please e-mail your responses to Quiz@vacaero.com listing the numbers 1 through 20Read more...

To maximize your investment and produce repeatable high-quality process results, it is mandatory to institute a thorough pump preventative maintenance program. In a pump’s normal operating life, nearly all unexpected vacuum pump failures can be prevented, and when carefully maintained,Read more...

Booster pumps (aka Roots blowers or intermediate stage vacuum pumps) fall into the class of dry, gas transfer pumps. As a dry pump, they do not introduce oil or water into the pumped gas stream. Gas transfer is accomplished byRead more...

Just as vacuum pumps can be considered the heart of the vacuum furnace, so too can the oil be thought of as its circulatory system. The selection and properties of the oil are critical to proper furnace operation. Pump oilRead more...

Every industrial vacuum furnace system uses a primary (aka mechanical) pump, which is also commonly referred to as a "backing" pump when either used in series with a booster pump, or used with both a booster and secondary ("high vacuum")Read more...

Last time we focused on the principles of operation of oil sealed rotary vane pumps including basic pump design, and pump oil. We now continue that discussion focusing on operational features and the inner workings of these pumps. Single Stage vsRead more...

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 areRead more...

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 andRead more...

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 overRead more...

Abstract ASTM Test Method E 112 says it covers test methods to determine the average grain size of specimens with a uni-modal distribution of grain areas, diameters or intercept lengths. It says that these distributions are approximately log-normal. But, it doesRead more...

Abstract For many years, ASTM E384 has stated that the load range for microindentation hardness testing with both Knoop and Vickers indenters is 1 to 1000 gf. But, it also states that tests that produce a Knoop long diagonal or aRead more...