Because So Much Is Riding On Us! Heat treating aircraft landing gear involves experience, precision and state-of-the-art equipment. Because of our ongoing commitment to excellence recognized by customer approvals from major Aerospace prime contractors, we’re proud to be one of the world’s largest subcontractors for processing landing gear components for commercial and military aircraft. The […]
Archives for September 2015
Heat Treating
A wide array of equipment and capabilities to meet your challenging requirements and diverse processing needs. VAC AERO specializes in vacuum heat treating and brazing of advanced materials and holds numerous customer and quality system approvals from prime manufacturers in aerospace and other high-tech industries. VAC AERO has the equipment and expertise to process a […]
Purchase Order – Terms and Conditions
CLICK ON LINK BELOW TO DOWNLOAD PDF OF THE DOCUMENT VAC AERO – PURCHASE ORDER TERMS AND CONDITIONS 1. Incorporation of Terms and Conditions in Purchase Order These terms and conditions apply to all orders of products (“Goods”) and/or services (“Services”) by VAC AERO International Inc. (“VAC AERO”) and shall form a part of each […]
Pressure Relief Valves
One of the most critical components on any vacuum furnace is the pressure relief valve. While its function is clear, the fact that it needs to be inspected – and tested is either not well understood or simply ignored. Normally positioned atop a vacuum furnace it is in an area that is not always conducive to maintenance, and complicated in many instances by the fact that only the manufacturer can service them.
What is a Pressure Relief Valve? A pressure relief valve is a safety device designed to protect a vacuum furnace from over-pressurization. An overpressure event refers to any condition that would cause the pressure to increase beyond the specified design pressure (the so-called maximum allowable working pressure or MAWP). The pressure relief valve is an integral part of the safety system provided on most vacuum furnaces. Vacuum vessels, including evacuated chambers and associated piping, pose a potential hazard to personnel and the equipment itself from collapse, rupture, or implosion.
Very Low Loads in Micro-indentation Tests Must Be Avoided
For many years, ASTM E384 has stated that test forces from 1 to 1000 gf can be used to determine the Vickers or Knoop micro-indentation hardness. But, is it realistic to consider using very low test forces when the indents are measured with a light optical microscope? ASTM E92 is being resurrected and changed to cover all test loads, micro- and macro-loads, from 1 gf to 120,000 gf. Most micro-indentation hardness testers manufactured over the last 50 years or more have provided the user with a 10X objective used to find the area of interest for testing and one measurement objective, 40X magnification being the most common. A few testers have offered 50X or 60X objectives to measure the indents. It is rare to find a tester with a multiple objective (and indenter) turret, such as the DuraScan system which has ports for 2 indenters and 4 objectives. But, even with the highest quality 100X objective, indents smaller than ~15 μm in length cannot be measured with adequate precision for realistic work. The ASTM standards should eliminate recommendation of use of test loads <50 gf for Vickers and <20 gf for Knoop.
In both ASTM E384 (Micro-indentation Hardness Test Standard) and the proposed revision and re-instatement of E92 (to cover both Macro- and Micro-Loads for Vickers and Knoop), test forces below 25 gf for both Vickers and Knoop testing are listed as permissible for use. The proposed E92 lists test forces for Vickers macro-testing up to 120 kgf , although no machine built in some time has provided forces above 50 kg. The original Vickers testers made in England did use test forces up to 120 kgf, but that is a historical fact, irrelevant today.
Come Visit VAC AERO at the ASM Expo, Booth 606 – Detroit, October 21-22
We’re excited to be exhibiting at the ASM Heat Treating Expo and look forward to seeing you in Detroit! If you plan on attending the show, please be sure to stop by our booth number 606 to learn more about our latest vacuum furnaces, and most importantly… we’re interested in learning about you, your business, […]
What is the Purpose of a Vacuum Pump
To successfully process component parts in a vacuum furnace, we need to create and control the “atmosphere” surrounding the work. In general, applications run in vacuum furnaces can be broken down into five main (5) categories: 1) Processes that can be done in no other way than in vacuum; 2) processes that can be done better in vacuum from a metallurgical standpoint; 3) processes that can be done better in vacuum from an economic viewpoint; 4) processes that can be done better in vacuum from a surface finish perspective and, 5) process that can be done better in vacuum from an environmental perspective.
A principal difference between vacuum heat treatment and all other forms of thermal processing is the absence of, or perhaps better stated, the precise control of surface reactions. In addition, vacuum processing can remove contaminants, and under certain circumstances degas or convert oxides found on the surface of a material. Typical vacuum applications include industrial, food and packaging, coatings, analytical and medical technology, solar, semiconductor technology and research and development. In the heat-treating industry typical processes involve: Brazing, Hardening, Annealing, Case Hardening (e.g. carburizing, nitriding), Sintering, Tempering and Special Processes (e.g. degassing, diffusion bonding).