October 4, 2016

Fujikura Ltd. (President & CEO: Masahiko Ito) has succeeded in making Magnetocaloric material (hereinafter referred to as MCM) into wire. MCM is used for magnetic refrigeration technology suitable for environment-friendly next-generation refrigerators. Our wire drawing technology, one of our core technologies, has achieved the smallest diameter in the world, and has demonstrated that using a thin wire-like MCM achieves a refrigeration capacity far greater than those using a conventional granular MCM.

A magnetic refrigerator makes use of the magnetocaloric effect, which is a phenomenon in which MCM generates/absorbs heat in accordance with the application/removal of a magnetic field (Fig. 1) and has remarkable features such as (1) being capable of using a refrigerant with zero global warming potential (GWP) and (2) being overwhelmingly highly efficient, when compared with a conventional refrigerator. These features are expected to contribute greatly to the environment.

Conventionally, a granular shape was standard in MCM owing to manufacturability and ease of filling. However, it had the drawback of the refrigerant not flowing easily (Fig. 2). It made it difficult to achieve a refrigeration cycle with a higher frequency and was a major cause of inhibiting improvement in refrigeration capacity. Under the circumstances, Fujikura took on the challenge of developing a magnetic refrigeration wire which was said to make the refrigerant flow more easily than in the case of a granular material. But this was considered difficult to manufacture (Fig. 3). Use of the developed wire made it possible to operate a refrigeration cycle at a high speed of 10 Hz or more and has drastically improved the refrigeration capacity compared with the result of our experiment using a granular material. The achievement gained attention in Thermag VII, an international conference held in September 2016 in Torino. From now on, we aim to practically apply the technology to chillers, refrigerators, air-conditioners, and other appliances.