Analysis of Vibration Damping Mechanisms of Cu-Sn/Al₂O₃Composite Material by Frequency Response Function of FFT Analyzer

Abstract

In the fields of an eco-friendly automobile, an advanced industrial machine, and a precision electronic device, controlling of vibration damping behavior of the sintering parts obtained from powder metallurgy is required. In this paper, the vibration behavior of Cu-Sn/Al 2 O 3 composite material made by powder metallurgy was investigated by a FFT analyzer.Cu, Sn, and Al 2 O 3 powders were used as initial substances. The powders were mixed and pressed into a plate shaped compact with 200 MPa. Using a vacuum furnace, the green compact was sintered at 825-1075 °C for 1 hour. By changing the mixing ratio and the sintering temperature, some kinds of the composite material plates were produced. For the composite material obtained, microstructure observation, Vickers hardness test, compression test and vibration test were performed.The composite materials were consisted from the crystal grain of 15-69 μm, and the mixed Al 2 O 3 particles were dispersed on the grain boundary. Additionally, twin crystal was also found in the composite materials. The damping coefficient of composite material depended on the mixing ratio of the raw powders and the sintering microstructure. The vibration damping behavior of the Cu-Sn/Al 2 O 3 composite material was affected by solubility element, grain boundary, dispersoid particle, and twin crystal. KEY WORDSvibration damping mechanism, damping coefficient, FFT analyzer, frequency response function, Cu-Sn/Al 2 O 3 composite material

Vibration Damping Analysis of Cu-Sn/Carbon Fiber Sintered Composite Materials by Frequency Response Function of FFT Analyzer

“…On the other hand, for Cu-Sn/Al 2 O 3 , Cu-Sn/Graphite sintered composite materials, vibration damping coefficient was depended on the mixing ratio of disperse particle, and twin crystal is introduced in the Cu-Sn matrix phase cause by interface energy between matrix phase and disperse particle, and it was found that vibration damping behavior of Cu-Sn/Al 2 O 3 , Cu-Sn/Graphite sintered composite materials was affected by the twin crystal of Cu-Sn matrix phase 6,7) . However, effect of shape of dispersed particle is not clear yet.…”

“…The powders and fiver were mixed, and Cu/Sn/Carbon fiber premixed powder was prepared. The mixing ratio of Cabon fiber were set to 5%, 10% as same manner of the previous paper 6,7) . These premixed powder was pressed with 200 MPa, and plate shaped compacts of L = 120 mm, W = 20 mm, t = 10 mm were made.…”

“…according to solidus line in Cu-Sn phase diagram 6,7) . For the Cu-Sn/ Carbon fiber composite materials obtained, measurements of densities, microstructure observation, micro Vickers hardness testing, compression test, and vibration damping test were performed.…”

“…And, for the value measured by the FFT analyzer, the dumping coefficient was calculated as same manner of previous paper [5][6][7] .…”

“…The vibration damping testing of the test piece by a FFT analyzer was performed as same method of previous paper 6,7) . And, for the value measured by the FFT analyzer, the dumping coefficient was calculated as same manner of previous paper [5][6][7] .…”