Midget servomotor developed for aircraft: A two-phase servomotor developed by General Electric is believed to be the smallest currently used on aircraft. Originally developed for use in a gyrocompass unit, it may be adaptable to other uses, say GE engineers. The motor weighs 1.2 oz, measures 1.2 in. long, and has a diameter of 0.625 in. It is rated at 26 V with a no-load speed of 21,000 rpm. The motor is designed to withstand 55 to 90°F temperatures and is said to operate at altitudes up to 60,000 ft.
Chrome coat hardens steel: Heat, wear, and corrosion resistance of ferrous metals are increased by high-temperature diffusion of chromium onto the surface. Called "Chromallizing," the process is reported to be well known in Europe and is coming into use in this country.
According to Chromalloy Corp., the process diffuses chromium into the base metal to form an alloy layer that doesn't spall, peel, or flake.
The process can develop a ductile coating (0.001 to 0.003 in.) of chromium on lowcarbon steel. On medium to highcarbon content steels, a thin (0.0002 to 0.0010 in.) extremely hard (Vickers 1800) chromium carbide layer is formed.
The technique may let lowcarbon steels be used in applications that usually require a Type 400 Series stainless steel.
Reported successful uses of the process include electric strip heaters, turbine liners, and various aircraft components.
