Chemical milling of high tungsten content superalloys

USRE31823E · kind E · reissue

Assignee

• UNITED TECHNOLOGIES CORPORATION · US

Inventors

• Robert E. Fishter · Boca Raton, US
• Henry F. Lada · Cypress, US
• Brian A. Manty · Lake Park, US

Key dates

• Filing date: Oct 11, 1983
• Grant date: Feb 5, 1985
• Expiry date: Oct 11, 2003

Classification

• Technology area (CPC —): General

Abstract

Chemical milling of cast superalloys having high tungsten contents is advantageously accomplished with an etchant which consists by volume percent of 40-60 concentrated HNO.sub.3, 0.6-0.8 concentrated HF, .[.30.]..Iadd.40.Iaddend.-70 H.sub.2 O, with which is included at least 0.008 moles/liter CuSO.sub.4 and 0.0016-0.025 moles/liter FeCl.sub.3. Preferably the molar ratio of CuSO.sub.4 to FeCl.sub.3 is 2:1 and etching is accomplished in the range 50.degree.-80.degree. C.