The production and application of Japanese Irogane alloys.

The applicant holds an AHRC Fellowship in the Creative and Performing Arts. The research program is entitled 'The production and application of Japanese alloys and patination' and will run from May 2007- April 2010. The material and other costs covered by this application are central to the program of research proposed for the fellowship.

The Western tradition of metal patination and colouring is based on the use of a small range of metals and alloys which are coloured by the application of a wide range of patination solutions. In contrast to this, Japanese metalworkers developed a wide range of irogane alloys which are coloured with a single patination solution (the niiro eki or boiling colour solution). This approach allows different alloys to be combined in one piece and patinated, producing a multi-coloured piece of metalwork.

Irogane alloys are produced primarily on a small scale by skilled craftsmen with many years experience. In order to realise the potential of these alloys it is necessary to study the metallurgy of the alloys and the variations that result from the use of traditional and modern casting techniques. An understanding of the structure and behaviour of the cast alloys may also lead to improvements in the alloys, their processing, and the quality and consistency of the finished products. We will also look at the optimisation of the alloys for practical studio work through the use of micro alloys to control mechanical properties such as hardness and ductility.

This project will look specifically at the reliable production of shakudo (gold/copper), shibuichi (copper/silver), and kuromido (copper/arsenic) alloys. An initial list of alloy compositions to study will include Cu-99% Au-1%, Cu97% Au-3% and Cu-70% Ag-30%. Subject to health and safety considerations a Cu-99% As-1% is also a candidate material.

The research will ask:

1. What are the fundamental metallurgical properties of the irogane alloys?

2. How do the alloys respond to small workshop and industrial production methods? Do they differ and in what way?

3. How will the metallurgical properties of the alloys change during processing and practical studio work?

4. How can we optimise the materials for practical studio work through the use of microalloys?

The research will be located at Sheffield Hallam University (SHU) using the facilities and expertise of the Art and Design Research Centre (ADRC) and the Materials and Engineering Research Institute (MERI). There is a strong team of highly experienced and internationally recognised Metalwork and Jewellery staff at ADRC to support the research. MERI has the background of precious metals research, and the extensive equipment and materials characterisation techniques essential to support this research.

Papers will be submitted to scientific, design and craft related journals. The University website will be utilized for the publication of papers, exhibited works etc. Commercial collaborators will be sought through SHU to exploit any materials or processes that are developed.

The research program will allow me to significantly advance knowledge of technical issues relating to irogane alloys. This project is a fundamental part of the larger research programme as high quality alloys will be necessary for the study of the niiro patination technique and the production of my studio work. The proposed research will build on traditional craft knowledge and on contemporary technical research. This research will be a great contribution to the understanding of Japanese metalsmithing techniques, providing information and solutions to the problems faced by contemporary metalsmiths working with these materials, while also widening the area of possible applications and expression. This research will be of interest to metalsmiths, product designers, the metal finishing industry, and the materials science community.