American Machinist

Creep-feed methods speed blades. (Howmet Corp. increases production of jet-engine turbine blades)

Creep-feed methods speed blades

BY MERGING THREE DISCIPLINES--the manufacturing-cell concept, ergonomics, and high-tech grinding--the Howmet Corp's Machining Div (Winsted, Conn) reduced lead time and increased production of jet-engine turbine blades from several hundred a month to several hundred a day.

Installing the "cell" approach and increasing productivity through operator ergonomics was only part of the task. Incorporating creepfeed grinding into the cell, particularly the continous-dress technology, proved both challenging and rewarding.

The parts involved are high-tech turbine blades and vanes. These are precision investment-cast products from another Howmet division> following machining they will be sent to jet-engine manufacturers like GE, Pratt & Whitney, Rolls Royce, Garrett, Fiat, etc.

The materials are mostly cobalt-or nickel-based superalloys like Inconels and REnes. The materials are extremely tough, with machinability indixes of 8% to 12% of the of cold-rolled steel. The castings start with 0.030 to 0.150-in. Excess stock, removed during machining.

Abrasive machining

A few years ago, Howmet's productivitity team began planning the "cell" approach to their machining operation. …

Log in to your account to read this article – and millions more.