Review Article

Vapour deposition technologies for the fabrication of hot-forming tools: a review

¹ Center of Advanced Surface Engineering, AIN, Cordovilla-Pamplona E31191, Spain
² School of Metallurgy and Materials, University of Birmingham, Edgbaston B15 2TT, UK
³ Dept. of Design, Manufacture and Engineering Management, The University of Strathclyde, G1 1XJ Glasgow, UK
⁴ Dpto. de Ingeniería de Superficies, Universidad Complutense de Madrid, 28040 Madrid, Spain
⁵ IMEM Department, Universidad Pública de Navarra, E31006 Pamplona, Spain

^* e-mail: gfuentes@ain.es

Received: 31 July 2014
Accepted: 9 November 2014

Abstract

This paper reports recent developments of vacuum coatings technologies for hot-forming tooling applications. Whilst well implanted in the machining and cutting industry, vacuum coatings face important challenges for the fabrication of forming tools, and more specifically in hot forming, due to the extreme operation conditions to be met, such as high loading forces, impact/thermal cycling, working material adhesion, etc. Present and future coatings adapted to hot work tooling are discussed in this paper: transition metal nitrides, carbon nitrides, borides and mixed oxides are among the currently postulated coating formulations for high temperature forming. The study is complemented with current strategies of characterizing the properties of the coatings in the adequate environment of high temperatures and contact loadings. To this aspect, a number of examples, from using standard laboratory equipment to the use of in-house developed tribological set-ups, are given, together with recent findings obtained from the authors’ research groups. The data available is, however, quite limited from the scientific literatures on the field trials with reliable, statistical relevance, which is, probably, attributed to the high costs normally incurred for carrying out experiments in real industrial environment. Nevertheless, we could still draw a conclusion of that vacuum coating for tooling applications is at a front edge of knowledge generation and technology transfer to industry, and while being already mature, there is still a needed effort for significant industrial up-take from the novel coatings developed or being under the development.