Patent ID: 8241561

Claim:
A stress-buffering material including a Ca-containing aluminum alloy consisting of: Al, 7.9 to 12 at % of Ca, and unavoidable impurities as an elementary composition, wherein the Ca-containing aluminum alloy includes a first phase of Al and a second phase including Al 4 , Ca, wherein a volume fraction of the second phase of Al 4 Ca is within a range of 20 to 70%, and wherein an average size of the second phase of Al 4 Ca is within a range of 0.01 to 20 μm, and wherein when I A1 (111) represents (111) surface reflection intensity of Al and I Al4Ca (112) represents (112) surface reflection intensity of Al 4 Ca, a diffraction peak of Al and Al 4 Ca by an X-ray diffraction method meets a following formula: 2.5≦ I Al (111)/ I Al4Ca (112)≦100, and wherein static Young's modulus of the Ca-containing aluminum alloy is 60 GPa or less, dynamic Young's modulus of the Ca-containing aluminum alloy is 55 GPa or less, and both the static and the dynamic Young's moduli are determined according to Japanese industrial Standards Z 2280:1993 and are measured at room temperature.