Effects of Macroscopic Pores on the Damping Behaviors of Metal Materials

Abstract

A large number of macroscopic pores were introduced into commercially pure aluminum (Al) and Zn-Al eutectoid alloy by air pressure infiltration process to comparatively study the influence of macroscopic pores on the damping behaviors of the materials. Macroscopic pores size are on the order of a millimetre (0.5~1.4mm) and in large proportions, typically high 76vol.%. The damping behavior of the materials is characterized by internal friction (IF). The IF was measured on a multifunction internal friction apparatus (MFIFA) at frequencies of 0.5, 1.0 and 3.0 Hz over the temperature range of 25 to 400 °C, while continuously changing temperature. The damping capacity of the metal materials is shown to increase with introducing macroscopic pores. Finally, the operative damping mechanisms in the metal materials with macroscopic pores were discussed in light of IF measurements.

Study on Preparation of Foamed Zn-Al Eutectoid Alloy by Air Pressure Infiltration Process

“…After infiltration process, the container system was cooled to obtain a Zn-Al/NaCl compact, the amount of NaCl in the compact was leached by immersion in a water bath at 25 ºC for three hours, to generate the foamed Zn-Al eutectoid alloy with interconnected cells. [4,7,8]. The obtained foams showed a highly porous structure with interconnected cells in all cases.…”

Preparation of foamed commercially pure aluminum by air pressure infiltration process

“…Figure 2 shows the typical photo of foamed commercially pure aluminum prepared by air pressure infiltration process. The macroscopic pores in the foamed commercially pure aluminum are open and most are regular circle [4,7]. Foamed commercially pure aluminum has a quite uniform macroscopic pore and density distribution through the section.…”