While precious metals possess valuable physical and chemical properties, their processing requires high levels of technical expertise. We prioritize the development of processing techniques for mass production alongside material design of precious metals. We set optimal conditions for casting, forging, rolling, heat treatment, machining and other process, ensuring the final dimensions and shapes meet our clients' requirements.
Iridium Alloy: Challenging Microfabrication of Heat-Resistant Material
The electrodes used at the tips of automotive spark plugs must withstand the extreme conditions of high temperature and oxidation within the engine. In the 1990s, a collaborative development project has been initiated to create a new material that surpasses the conventional platinum electrodes. Among the various materials under investigation, iridium alloy showed the most promising potential.
However, the hard and brittle nature of iridium posed challenges in its processing. Its Young's modulus and hardness are more than three times higher than those of steel, rendering it a challenging material for plastic deformation and machining. Consequently, it was believed to be impossible to achieve the microfabrication, that is necessary to improve the ignitability of spark plugs. Despite such circumstances, we took on the challenge of developing iridium alloys and technologies for microfabrication and the processing of heat-resistant materials while leveraging the expertise we have cultivated over many years of operation.
Due to its high heat resistance, special know-how is required for hot working processes of iridium. For example, the processing temperature for iridium needs to be several hundred degrees Celsius higher than that for steel. Additionally, precise temperature control is essential for performing high-precision machining, as the material properties change significantly with temperature variations. It necessitated the installation of dedicated fixtures and equipment capable of withstanding high-temperature processing for us.
After several years of trial and error in dealing with various other technical issues, we finally established a microfabrication method for iridium alloys that is manufactured through the melting method, and achieved the world's first mass production of electrodes for spark plugs.