Resources

The development of particle accelerators was previously discussed (see Part 1 and 2 on Vacuum Technology at CERN). The use of the large hadron collider (LHC) located at CERN with its enormous, multiple vacuum systems is intended to investigate the[...]

Vacuum furnaces (Fig. 1) can use a variety of different gases during the processing cycle in partial pressure operation, for backfilling to atmospheric pressure at the end of the processing cycle and for cooling/quenching. The most common of these gases[...]

The basics of particle physics, the development of the particle accelerator, and the installation of the world’s largest such unit at CERN were discussed in Part 1. Here, we will take a closer look at this super collider and the[...]

In vacuum applications, cold traps are added to vacuum pumping systems either to remove unwanted contaminants (e.g. water, solvents, acidic or alkaline compounds) from the gas stream or to prevent pump backstreaming. These conditions can cause loss of efficiency or[...]

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, it[...]

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 systems[...]

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 used[...]

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, molecular[...]

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 systems[...]

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 them[...]

As we have seen in the last two articles, the fixturing used in furnace-brazing is a very important item that MUST be carefully considered if you want to minimize the time used in each brazing cycle (excess fixturing weight adds[...]

In this month’s article, we continue to look at methods you can use to keep fixturing-weight down to a minimum, especially in furnace brazing, remembering once again that fixtures (baskets, frames, grates, dead weights, etc.) represent a large mass of[...]

We look now at the fifth of the seven important criteria for good-brazing that are listed in Table 1, namely, the use of fixtures in the brazing process. Fixtures hold the parts being brazed, whether it is a metal vice[...]

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, if[...]

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,[...]

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 by[...]

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 oil[...]

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")[...]

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 vs[...]

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[...]

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 does[...]

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 a[...]