Highly complex assemblies, for a variety of end-use applications in such diverse fields as automotive, aerospace, medical, electronics, and tooling (just to name a few), can be effectively made via brazing.

For this to happen, however, each of the individual components in these complex assemblies must be able to be held together in proper alignment, have the appropriate brazing filler metal (BFM) applied to it, and this assembly then moved into a brazing-furnace, where it can be heated until the BFM melts and flows into the joints by capillary action, thereby permanently joining the components together to make a complex assembly. by Dan Kay

Commercial introduction of the Scanning Electron Microscope (SEM) in 1965, and its subsequent rapid development and implementation in metallographic laboratories, has had a profound influence on failure studies. The chief advantage of the SEM is its great depth of field in comparison of the light microscope. Observations can be made over a much wider range of magnifications including those above the range for light microscopes (and those below the range of TEM replicas). Examination of fracture features by SEM is much simpler than through the study of replicas with the Transmission Electron Microscope, TEM. A further advantage of the SEM is the chemical analytical capability of spectrometers that can be attached to the microscope, Energy-dispersive Spectrometers (EDS) being the most common.

The study of fractures with the unaided eye has been practiced since antiquity chiefly for controlling the quality of metals production. R. A. F. de Réammur may have been the first to examine and publish drawings of fractures examined at high magnifications, at least 100X, in 1722. R. Mallet appears to have been the first to link fracture appearance to service performances in a study of failed cannon barrels published in 1856. Adolf Martens may have been the first to study both fracture surfaces and the underlying microstructures in 1878 followed by the first description of fracture surface features in 1887 when he showed that these lineal features could be traced backward to identify the fracture origin. By George Vander Voort

In the world of mechanical oil sealed rotary vacuum pumps there is a need for a variety of oils and fluids to suit the specific type of pump, its duty and the process it is used on. This discussion covers high vacuum pumps only, such as are used in the heat treating and vacuum furnace industry. These same vacuum pumps are used in many other industrial and scientific applications and have to work under many different types of conditions including one that many people expose their pumps too – neglect!.

Rotary vane vacuum pumps are available as direct drive (usually 1800 rpm) and vee belt drive (between 400 and 500 rpm) versions. Rotary piston vacuum pumps are generally vee belt driven and run at about 500 rpm. The work duty of a vacuum pump can vary between intermittent use and running continuously. They can also be used for cyclic duty, to evacuate a loadlock for example, where the pump evacuates a chamber from atmosphere to vacuum every few minutes. The vacuum process can also vary, from clean air pumping to hazardous gas, wet vapor pumping and dirty/dusty atmospheres.. By Howard Tring

The metallographic laboratory is a relatively safe working environment; however, there are dangers inherent to the job. Included in these dangers is exposure to heat, acids, bases, oxidizers and solvents. Specimen preparation devices, such as drill presses, shears and cutoff saws, also present hazards. In general, these dangers can be minimized if the metallographer consults documents such as ASTM E 2014 (Standard Guide on Metallographic Laboratory Safety) and relevant Material Safety Data Sheets (MSDS) before working with unfamiliar chemicals. Common sense, caution, training in basic laboratory skills, a laboratory safety program, access to safety reference books – these are some of the ingredients of a recipe for laboratory safety.

Safe working habits begin with good housekeeping. A neat, orderly laboratory promotes safe working habits, while a sloppy, messy work area invites disaster. Good working habits include such obvious, commonsense items as washing the hands after handling chemicals or before eating. Simple carelessness can cause accidents. For example, failure to clean glassware after use can cause an accident for the next user. Another common problem is burns due to failure to properly clean acid spills or splatter. By George Vander Voort

Fastener applications are demanding. Whether fasteners are being used in the petrochemical industry, in medical or mining applications, for assembly of marine or nuclear components or in the aerospace, automotive or construction world, vacuum processing allows us to repeatedly achieve the highest quality and metallurgy.