3.1 Titanium for airframes
The two biggest aircraft manufacturers in the world are the Boeing Company in the USA and Airbus S.A.S. in Europe. Although Boeing is better known in Japan, Airbus is also obtaining an increasing presence there, with delivery of its aircraft reaching 100 in March, 2013. Figure 3 gives the names of Japanese companies that have joined the development of the A380 (full double-deck type with a seating capacity of 525 in a standard cabin configuration), the biggest aircraft manufactured by Airbus. Twenty-one Japanese companies including Nippon Steel & Sumitomo Metal are listed. This demonstrates a strong bond between Airbus and the Japanese aeroFigspace industry. Affiliation between Nippon Steel & Sumitomo Metal and Airbus dates back to 1997, when Airbus was merely a consortium of companies in Germany, France, the UK and Spain.
Nippon Steel & Sumitomo Metal originally delivered pure titanium sheets to Daimler Chrysler AG in Germany and to the Aerospace Corporation. Later in 2001, Airbus became an integrated enterprise, and since 2002 Nippon Steel & Sumitomo Metal has continued to deliver pure titanium sheets. Pure titanium sheets delivered to Airbus are produced based on standards specified by the company, and stable quality and delivery control are crucial. In order to achieve this, acquisition of the Aerospace Quality Management System (JIS Q 9100) and the international special process accreditation program (Nadcap: National Aerospace and Defense Contractors Accreditation Program) were required. Occasionally, specific control is required by Airbus.
Titanium application purposes for aircraft are shown in Table 2. Outside temperatures during flight can be − 60˚C or lower; however, titanium is resistant to embrittlement at low temperatures. Furthermore, there is no concern about corrosion even when dew condenses after a drop in temperature. Moreover, since its low thermal expansion is close to that of CFRP, titanium proves to be a material appropriate for aircraft. Commercially pure titanium is equipped with all of the characteristics ① to ⑤ listed in Table 2, and is therefore used for various airframe parts. Examples of such applications are the nacelle at the entry of an engine, parts of the pylon for hanging engines, and hot air piping (bleed air tubes) that prevents freezing. These parts require reliable performance, irrespective of the size of the airframe and design, and Nippon Steel & Sumitomo Metal has long devoted itself to quality stabilization, and has as a result received high appreciation from customers.