“…In the meantime, some flaky pieces of TZM were transferred to the surface of the counterpart ball (Point 5 in Figure 3c) as schematically shown in Figure 14a. This is because molybdenum is well known for its adhesive character as it has a strong bond to glasses, polymers, ceramics and other materials [11,12]. For example, molybdenum has been added into Al 2 O 3 ceramic as a binding phase or forming a laminate structure to improve the fracture toughness of the ceramics used in cutting tools [13,14], solar selective absorbing coatings [15] and catalysts [16] etc.…”