CaCl2作为造孔剂制备泡沫青铜的结构和力学性能

以青铜粉为原料、CaCl_2为造孔剂,采用粉末烧结溶解法制备开孔泡沫青铜。通过改变造孔剂体积分数和粒径成功制备出孔隙率为70%~90%,孔径1~3mm的泡沫青铜试样。研究了孔隙率和造孔剂的关系以及孔隙率、孔径对泡沫试样力学性能的影响,并对其孔结构,相组成和微观形貌进行观察和分析。结果表明:泡沫青铜试样的塑性屈服平台应力随孔隙率增加而减小,当孔隙率为77%~89%时,对应塑性屈服平台应力为12.6~2.6MPa。当应变量为50%时,孔隙率为77%~89%的泡沫青铜单位体积能量吸收值(W)范围为6.21~0.91MJ/m~3。试样的理想吸能效率(I)都接近0.82,说明泡沫青铜可以作为一种理想的吸能材料。

Microstructure and Mechanic Properties of Bronze FoamsPrepared with CaCl2 as Space Holder

Bronze powder was used as the raw material and calcium chloride as the space holder. The open cell?bronze foams have been fabricated by sintering and dissolution process (SDP). By varying the volume percentage and the size of the space holder, the bronze foams with porosity ranging from 70% to 90%, and cell size from 1 to 3 mm were produced successfully. The relation between the volume percentage of the space holder and the porosity of?bronze foams was investigated, and the effects of porosity and pore size on the mechanic property of bronze foams were also studied. The pore structure, phase composition and micro structure of bronze foams were observed and analyzed. The experimental results show that plateau stress of bronze foams increases with the decrease of porosity, and the plateau stress is in the range from 12.6 to 2.6 MPa with the porosity of ranging between 77% and 89%. The energy absorption per unit volume (W) of bronze foams with the porosity between 77% and 89% is in the range of 33.5~5.1MJ/m3 when strain is 50%. The maximum ideality energy absorption efficiency is about 0.82. All the results indicate that the bronze foam is a kind of energy absorption material.