Core removal Howard Pickard LBBC Technologies Leaders in

Core removal Howard Pickard LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Core removal LBBC Technologies Suppliers of autoclave systems Dewaxing Boilerclave. TM Core Leaching autoclave LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Core removal LBBC Technologies Suppliers of autoclave systems with Quicklock. TM doors Independent family owned Established over 130 years Variety of autoclave applications Equipment development Service and support LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Shell removal vs Core removal LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Shell vs Core removal Removal of the shell involves… metal shrinkage assists the process large ceramic particles mechanical methods Removal of a core involves… small ceramic particles complex geometry enclosed areas LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Cores Used by a minority of foundries Increases applications for investment castings Implications throughout process Removal perceived to be the hardest stage Considering only Silica based cores LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Removal of core Key issues • Geometry • Is it possible to remove? • Metal Alloy • Susceptible to attack • Cost • Market potential, capital investment • Health & Safety • Exposure of operators, waste by-products • Environment • By-products of the process LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Removal of core methods n n n Hydraulic cleaning Sand blasting Caustic bath / mechanical agitation Caustic autoclave Molten caustic Ultrasonics LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Removal of core n n n methods Hydraulic cleaning Sand blasting Caustic bath / mechanical agitation Caustic autoclave Molten caustic Ultrasonics Advantages Good method for simple core geometry. Low health and safety issues. Description High pressure water jets erode core particles then recirculate within machine Best practice • Large non complex cores Disadvantages Can be difficult and time consuming to remove the core. LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Removal of core n n n methods Hydraulic cleaning Sand blasting Caustic bath / mechanical agitation Caustic autoclave Molten caustic Ultrasonics Advantages Effective at removing large cores with low complexity. Low health and safety issues. Good casting finish Disadvantages High level of dust. High possibility of casting wear. Description Grit or shot is fired at the core passage within a cabinet either by compressed air or an impeller. Best practice • Grade of shot/grit. • Mechanical separation LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Removal of core n n n methods Hydraulic cleaning Sand blasting Caustic bath / mechanical agitation Caustic autoclave Molten caustic Ultrasonics Advantages Low cost, simple method for removing cores. Minimises erosion of casting. Disadvantages Can take long time for large or complex cores. High level of health, safety and environmental risks Description Sodium or potassium hydroxide solution (35 – 50%) in a tank at room or elevated temperature. Parts placed into solution and left for liquid to break down the core material. Mechanical or air agitation may be added. Best practice • Consider agitation • Automate systems • Drill holes first LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Removal of core n n n methods Hydraulic cleaning Sand blasting Caustic bath / mechanical agitation Caustic autoclave Molten caustic Ultrasonics LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Core leaching autoclave LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Core examples Courtesy of Certech LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

The process The Equipment LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

The process Load Baskets LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

The process Typically 120 psi 160 o. C Na. OH 20% KOH 40% Fill & Cycle LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

The process Dump LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

The process Wash LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Core leaching autoclave Best practice • Na. OH or KOH • Speed, recycle • Concentration • High / low, temperature • Component orientation • Up or down, horizontal • Cycle parameters • Dwell, vent, mid way break • Recycle caustic • Cost, efficiency • Post leach operations • Water wash LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Removal of core n n n methods Hydraulic cleaning Description Sand blasting Bath of molten concentrated caustic. Caustic bath / mechanical agitation Castings placed inside Caustic autoclave Molten caustic Ultrasonics Advantages Quick and effective at removing cores Disadvantages Many health and safety issues. Likely to attack the casting alloy surface Best practice • Take great care • Check suitability of alloy LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Removal of core n n n methods Hydraulic cleaning Sand blasting Caustic bath / mechanical agitation Caustic autoclave Molten caustic Ultrasonics Advantages Speeds up the process Non contact Disadvantages Early development of the process. Untested. Description Use of ultrasonic rays to break down macroscopic structures Best practice • Research phase – no commercial system LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Removal of core Consider the key issues Be aware of the alternative methods Review the operation Increase application of investment castings Increase yield Improve quality LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Shell and Core removal Special thanks to : Dr Brian Robson Casting Solutions Limited Email : brianrobson@live. com References • Fettling and finishing, Dr Alan Clegg, EICF workshop 2004 • Leaching of preformed ceramic cores, Miller & Eppink, Sherwood Refractories, ICI 1983 LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com

Thank you LBBC Technologies Leaders in autoclave technology www. lbbctechnologies. com