Method for processing alloys via plasma (ion) nitriding

US7695573B2 · kind B2 · utility

Assignee

• SIKORSKY AIRCRAFT CORPORATION · US

Inventors

• Clark V. Cooper · Glastonbury, US
• Krassimir Grigorov Marchev · Sudbury, US
• Bill C. Giessen · Cambridge, US
• Raymond C. Benn · Huntington, US
• Edward H. Bittner · Madison, US
• Harsh Vinayak · Bhangrola, IN

Key dates

• Filing date: Sep 9, 2004
• Grant date: Apr 13, 2010
• Expiry date: Apr 8, 2028

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C8/36
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A surface processing method and power transmission component includes transforming a surface region of a metal alloy into a hardened surface region at a temperature that is less than a heat treating temperature of the metal alloy. The metal alloy includes about 11.1 wt % Ni, about 13.4 wt % Co, about 3.0 wt % Cr, about 0.2 wt % C, and about 1.2 wt % Mo which reacts with the C to form a metal carbide precipitate of the form M2C. The surface processing temperature, vacuum pressure, precursor gas flow and ratio, and time of processing are controlled to provide a desirable hardened surface region having a gradual transition in nitrogen concentration.