STP964

    Anelastic and Elastic Measurements in Aluminum Metal Matrix Composites

    Published: Jan 1988


      Format Pages Price  
    PDF Version (136K) 9 $25   ADD TO CART
    Complete Source PDF (8.9M) 9 $70   ADD TO CART


    Abstract

    The piezoelectric ultrasonic composite oscillator technique (PUCOT) has been used at temperatures up to 638 K and at 80 kHz to measure dynamic Young's modulus E, mechanical damping or internal friction Q−1 and strain amplitude ϵ in Al/SiCw and Al/Sicp. For four adjacent specimens from one sheet of 6061 Al/SiCp E-values varied in the range 114–119 GPa at room temperature. The composition dependence of the modulus followed E = 68.6 + 2.2X with R = 0.95 (E is in GPa and X in volume percent SiC). The temperature dependence of the dynamic modulus followed E = 138.7 − 0.11T with R = 0.98 (E is in GPa and T in Kelvin). The amplitude dependence of Q−1 for 6061 Al/SiCw revealed a damping peak at ϵ = 10−6. An analysis of the internal friction data in terms of a damping theory yielded values for the minor pinning length of dislocation lines and the density of mobile dislocations. The results are discussed in terms of the microstructure.

    Keywords:

    dynamic modulus, damping, internal friction, temperature, composition, aluminum, silicon carbide, metal matrix composites, composites, dislocations, whiskers, particles, mechanical properties, anelasticity, elasticity


    Author Information:

    Wolfenden, A
    Professor and lecturer, Texas A&M University, College Station, TX

    Harmouche, MR
    Professor and lecturer, Texas A&M University, College Station, TX

    Hayes, SV
    Lead engineer, LTV Aerospace and Defense Company, Dallas, TX


    Paper ID: STP25954S

    Committee/Subcommittee: D30.07

    DOI: 10.1520/STP25954S


    CrossRef ASTM International is a member of CrossRef.