Papers by Keyword: Mechanical Properties at Elevated Temperature

Abstract: In order to improve the high-temperature strength of an Al-Cu-Mg alloy, Mn was added at supersaturation to form a high-density dispersion of an intermetallic phase. In the P/M Al-3.6Mn- 6.4Cu-3.6Zn-1.7Mg alloy (mass%), rod-like Al-Mn-Cu-Zn quaternary intermetallic phases (Q phase) several hundred nanometers in length were dispersed in the matrix. The chemical composition of the Q phase was determined by TEM/EDX to be 78.8Al-12Mn-8Cu-1.2Zn (at%). The crystal system, space group, and lattice parameters of the unit cell were identified to be orthorhombic, Cmcm and a = 0.76, b = 2.11, c = 1.25 nm, respectively, by Rietveld analysis. Since the matrix of the alloy obtained was of the Al-Cu-Mg-(Zn) system, age-hardening occurred by formation of a GPB zone at room temperature and 448 K. At the peak level of age-hardening at room temperature, the tensile strength at room temperature was 704 MPa, and the elongations were 8.0%. The high temperature strengths at 523 and 573 K were 319 and 141 MPa, respectively, and the elongations were 17 and 34%, respectively.

Abstract: Aluminum-based alloys containing quasicrystalline particles of 50 – 600 nm in diameter as a reinforcing phase were produced in the form of powder or ribbons by water atomization or melt spinning techniques, respectively. Rods were compacted from powders and some ribbons by severe plastic deformation without sintering. Structure and mechanical behavior of alloys are discussed.