Compound body of vacuum-coated sintered material and process for its production

US5698314A · kind A · utility

Assignee

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US

Inventors

• Klaus Goedicke · Dresden, DE
• Gunter Hotzsch · Dresden, DE
• Fred Fietzke · Dresden, DE
• Olaf Zywitzki · Freiberg, DE
• Siegfried Schiller · Dresden, DE
• Jonathan Reschke · Dresden, DE
• Wolfgang Hempel · Dresden, DE

Key dates

• Filing date: May 22, 1995
• Grant date: Dec 16, 1997
• Expiry date: May 22, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2916
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Compound body of a vacuum coated sintered material and a process for its production. Such compound bodies, when coated in a known manner, have a carrier of sintered material coated with a layer that is thermally, mechanically and chemically unstable, with their surface showings cracks and being partially porous. These shortcomings are overcome via an improved eco-friendly vacuum deposition process, wherein at least one layer of a material, having an outer layer of Al.sub.2 O.sub.3, is applied to the carrier of sintered material at a maximum of 800.degree. C., with this layer being completely crystalline and comprised of an .alpha.Al.sub.2 O.sub..sub.3 phase and possibly of a .gamma.Al.sub.2 O.sub.3 phase with a (440) texture, having a compressive stress of at least 1 GPa and a hardness of at least 20 GPa, with the Al.sub.2 O.sub.3 layer being deposited via reactive magnetron sputtering, wherein the magnetrons are pulse driven, the pulse frequency lies between 20 and 100 Khz and the deposition rate is at least 1 nm/s, with the resulting compound bodies being utilized for cutting treatments, particularly as cemented carbide inserts.