Tech Downloads
Maximizing Vacuum Furnace Gas Quenching Performance
There are many areas that engineers must consider when attempting to design a new and high performance gas quenching vacuum furnace.
A Brief History of Vacuum Technology
The history of vacuum technology is a fascinating one. It seems to have begun in ancient Greece when the philosopher Democritus.
Gear Market Offers Opportunities for Ingenuity and Innovation
Solar’s Souderton plant recently received a Nadcap accreditation in carburizing, allowing it to better serve the aerospace market. This accreditation joins Solar’s other Nadcap approvals for heat treating, brazing and fluorescent penetrant inspection. Additionally, earlier this year the company became an approved supplier for General Electric Aviation (GEA), UTC Aerospace Systems (UTAS) and Moog Corporation.
Gas vs. Liquid Quenching: A Direct Comparison in Hardenability to Reduce Distortion
Hardenability is the ability of steel to partially or completely transform from austenite to some fraction of martensite at a given depth below the surface, when cooled under a certain condition.
Blended Gases – A Cost-Effective Alternative To Helium In Processing Reactive Metals
Argon and helium gases have been used and evaluated as quench gases within vacuum heat treating circles for many years.
Understanding Power Losses in Vacuum Furnaces
Since the early development of the vacuum furnace, engineers and thermal experts have continually tried to improve the insulating characteristics of the furnace hot zone. Several materials have been used for different applications with varying success. However, all designs must still deal with the heat losses penetrating through the insulation materials and the need to minimize these losses. This is especially important today with the continual escalation of electrical power cost. This paper will review the different types of hot zone insulation materials used, the projected losses of the different designs, the impact relating to furnace cycle heating rates and cycle times, and the projected cost advantages of one design over another.
Titanium Heats Up
Today, the trend for airframe manufacturers is the increased use of composite materials and titanium alloys. Compared to an aluminum structure, these composites provide a greater reduction in maintenance due to fatigue. When loading and environmental factors are analyzed, low maintenance, high strength titanium trumps aluminum again.
Understanding PID Temperature Control As Applied To Vacuum Furnace Performance
Proportional-Integral-Derivative (PID) control is the most common control type algorithm used and accepted in the furnace industry. These popular controllers are used because of their robust performance in a wide range of operating conditions and because of their simplicity of function once understood by the processing operator. The purpose of this paper is to further define and thoroughly explain the basics of the PID controller. It should be noted that many current instruments incorporate what is called an “Autotune” feature which can automatically set the PID variables for a given temperature setting allowing the operator to bypass much of the initial manual requirements. However, Autotuning was not introduced until the late 1980’s and there still exists many instruments in use which do not have this tuning feature and must still be manually set-up. Also, Autotuning often requires additional tuning or tweaking to reach final acceptable results. By understanding fully the basics of the PID functions as described below, it is hoped that any final adjustments or tuning will be simplified. Further discussion of the Autotune feature follows below. As the name suggests, the PID algorithm consists of three basic components: proportional, integral and derivative which are varied to get optimal response. If we were to observe the temperature of the furnace during a heating cycle it would be rare to find the temperature reading to be exactly at set point temperature. The temperature would vary above and below the set point most of the time. What we are concerned about is the rate and amount of variation. This is where PID is applied.
Raw VS. Part Heat Treatments – What is the Difference?
The fuzzy definitions of “raw material” and “parts” in specifications create variable and debatable heat treating quality standards.