泡沫钢的制备及三点弯曲性能

为了制备孔隙率较高、孔结构均匀、性能优良的泡沫钢板及夹芯复合板,以316L不锈钢粉为原料,Ca Cl2为造孔剂,采用粉末冶金烧结-溶解法制备不同孔隙率、孔径的泡沫钢,并用物理粘接法制备泡沫钢夹芯复合板。通过对泡沫钢板和夹芯复合板进行三点弯曲实验研究两者的抗弯曲性能。观察泡沫钢板的三点弯曲变形过程,分析孔隙率和孔径对泡沫钢板和夹芯复合板抗弯曲性能的影响,对比两者的极限抗弯载荷变化。结果表明:泡沫钢板的变形首先从薄壁不规则的孔壁开始,形成裂纹并进行扩展,最终导致宏观断裂;对于泡沫钢夹芯复合板,当孔隙率从69.4%增加至82.5%时,其所能承受的极限载荷从2345 N下降至1254 N,在相同孔隙率下,相比于泡沫钢板,夹芯板承受的极限弯曲载荷提升了15%~43%;当孔径从1.9 mm增加至3.9 mm,孔隙率约为73%时,其所能承受的极限弯曲载荷从2070 N下降至1528 N,与泡沫钢板相比,相同孔径下,夹芯板承受的极限弯曲载荷提升了15%~28%;在孔隙率和孔径相同条件下,泡沫钢夹芯复合板的抗弯承载能力比泡沫钢板提高15%以上。

Preparation and Three-point Bending Performanceof Steel Foam Plate

In order to fabricate steel foams with high porosity,uniform pore structure and high-performance, steel foams with different porosities and cell sizes were fabricated by a sintering-dissolution process using 316L stainless steel powder as raw material and CaCl2 as pore forming agent, and steel foam-sandwich panels were fabricated by physical bonding.Three-point bending tests were carried out to explore the bending performance of steel foam and steel foam-sandwich panels.The influence of the porosity and cell size of foam sample on the bending load was analyzed and discussed,and the bending strength of steel foam-sandwich panel was compared with steel foam sample.The results show that the bending deformation of steel foam is started at the weakest cell wall firstly,then the cracks are initiated and propagated,eventually the macroscopic fracture is caused.For steel foam-sandwich panels,the maximum load is reduced from 2345 N to 1254 N when the porosity is increased from 69.4% to 82.5%,whereas the maximum bending load of steel foam-sandwich panels is increased by 15%-43% with the same porosity.When the cell size is increased from 1.9 mm to 3.9 mm and the porosity is about 73%,the maximum bending load is reduced from 2070 N to 1528 N,whereas the maximum bending load of steel foam-sandwich panels is increased by 15%-28% with the same pore size.Under the same porosity and pore size,the steel foam-sandwich panels have excellent resistance to bending at least 15% higher than the steel foam.