网状结构高孔率泡沫钛的特性

Characteristic of highly porous foamed titanium with netlike structure

网状泡沫钛属于弹脆性多孔材料,其压缩曲线的平台区为锯齿形,并在总体上呈缓慢增长的趋势;其平台区结束的极限应变较大,且密实化阶段的应力-应变曲线不是那么陡峭。采用浸浆烧结法制备获得了一种孔率在85%~90%之间、孔径分布在1~3 mm之间的网状泡沫钛。结果表明:该泡沫钛制品的热导率随着样品孔率的提高而明显地减小,且总体上具有良好的隔热性能,孔率为87%~89%的试样的室温热导率为0.4~0.8 W/(m·K)。此外,还测试该泡沫钛试样在200~6300 Hz声频范围内的吸声系数,发现其第一共振频率出现在4000 Hz左右,此时试样的吸声系数达到约0.9。

The foamed titanium belongs to the elastic-brittle material, and its compression curve has a hackle-like plateau and rise slowly. The terminal strain is quite large when this plateau ends, and the stress?strain curve in the densification stage is not so steep. A sort of reticulated foamed titanium with porosity of 85%?90%and pore diameter of 1?3 mm was prepared by the organic foam impregnating method. The results show that the thermal conductivity decreases markedly with increasing porosity for this foamed titanium, which performs a good heat-insulation. The room-temperature thermal conductivity of the sample with 87%?89%porosity is 0.4?0.8 W/(m·K). In addition, the sound absorption coefficient of this foamed titanium is also measured in 200?6300 Hz, the first resonant frequency occurs at about 4000 Hz, and the sound absorption coefficient reaches up to 0.9.