Reclamation of Machinery Components using Plasma Weld Surfacing

Abstract

Reclamation techniques are gaining moment um due to the cost and downtime involved in the replacement cost of worn out components One of the latest techniques for rejuvenating worn out critical machinery components is to combine the plasma spraying and plasma welding techniques in a semi-transferred arc mode. Arc is controlled independently and precisely so that optimum deposition and welding currents can be used to melt and spray the metal powders of interest and then weld it to the base metal. Thus the process provides a good metallurgical bonding with minimum heat input and avoids warpage which is a vital parameter in case of critical components where dimensional stability to close tolerance are important.

Many important machinery components have been reported to be reclaimed using this technique. However, the success of the process depends on many important parameters like choice of powder metal, joint fit-up, machine settings, control of gas flows, powder feed rate, arc length, etc. The paper describes in detail the process used for reclamation of a critical aircraft component using programmable plasma weld surfacing machine and also mentions evaluation technigues used for assessment of quality standard of weld surfacing.