Development of Flame-Retardant Wrought Magnesium Alloys and Application of the Alloys to High-Speed Railway Body

The application of the flame-retardant magnesium (Mg) alloy, which is defined as Mg-Al alloy with several mass%Ca, is an effective way to improve flame retardance. In Japan, the national project of Innovative Structural Materials R&D was launched in FY2014. In this project, the development and performance assessment of the flame-retardant wrought Mg alloys for their allocation to high-speed railway bodies were conducted. In the first half of the project, wrought Mg-Al-Ca alloys corresponding to the A6005C (Al-Mg-Si) and A7204 (Al-Zn-Mg) alloys were developed, where the AX41 (Mg-4%Al-1%Ca (mass%)) alloy with superior extrudability corresponding to the A6005C alloy, the AX92 (Mg-9%Al-2%Ca), and AX81 (Mg-8%Al-1%Ca) alloys with good balance in mechanical properties corresponding to the A7204 alloy were developed. After the development of the new alloys, a prototype of the railway vehicle body was produced with the purpose of verifying their assembling, forming, joining, cutting, and surface treatment abilities. In FY2015-2016, prototypes of a part of the side panel of the railway body including windows were produced. In FY2017, a prototype of a part of a railway vehicle body with 1:1 scale cross section (1 m length) was produced. In FY2018-2019, an extra-large partial structure (3400 mm width, 2900 mm height, 5000 mm length) was produced.

Automated summary

The application of flame-retardant magnesium alloy is an effective way to improve flame retardance. Japan conducted the development and performance assessment of flame-retardant magnesium alloys for high-speed railway bodies.