Photo Credit: L&L Special Furnace Co. Inc.
L&L Special Furnace Co. Inc. (Aston, Pa., U.S.) has received an order for two atmosphere-controlled retort box furnaces used for debinding ceramic matrix composite (CMC) parts, along with powder medals processing (PM) and hot isostatic processing (HIP).
According to the company, CMC, other ceramic matrix components and additive manufactured (AM) parts, which were initially developed for bullet-resistive armor and cloth, are now becoming more routine materials for a wide range of industries, ranging from aerospace and military applications for CMC and AM, as well as a newly established presence in agricultural applications such as water desalinization, power and battery technology in providing lighter fuel cells for CMC, to improve transportation capabilities and reduce greenhouse emissions.
The main function of the furnace from L&L is to remove all organics and other materials used in the product prior to placing in a high fire vacuum chamber. This debinding process is said to be very important and ensures a strong, lightweight finished product.
The model XLC3648 furnace has a work zone of 23 inches wide x 23 inches high x 36 inches deep. The furnace has a single zone of control with a temperature gradient of ±20°F at 1,100°F using four zones of temperature control with biasing to balance any temperature gradients.
The furnace itself is constructed of low-mass insulating firebrick, the company notes, which enables quicker cool down times, further aided by a venturi cooling blower. The furnace is controlled by a Eurotherm (Worthing, U.K.) program control with overtemperature protection. There is also a programmable flow panel to control the nitrogen flow throughout the process.
Parts are heated to 1,220°F in a retort chamber that is pressurized with nitrogen. The by-products of the outgassing part are directed by pressure and flow out the rear of the furnace. The parts are then heated in a vacuum furnace to temperatures in excess of 2,300°F.
All L&L Special Furnace’s products can be configured with various options and tailored to meet specific thermal needs. Options include a variety of control and recorder configurations. L&L says it also offers furnaces equipped with pyrometry packages to meet ASM2750. A three-day, all-inclusive startup service is included with each system within the continental U.S. and Canada. International startup and training service is available by factory quote.
