7xxx系烧结铝合金沿样品长度的孔隙分布变化（英文）

Variation in pore distribution along sample length in sintered 7xxx aluminum alloy

对7xxx系Al-7Zn-2.5Mg-1Cu合金在流动氮气气氛下的烧结行为进行实验和计算流体力学模拟研究。3个尺寸为56 mm×10 mm×4.5 mm的长条样品在氮气流量为6 L/min的管式炉中同一批次进行烧结,样品间距为2或10 mm,烧结温度为620°C,烧结时间为40 min。实验结果表明,烧结样品不同截面上的孔隙分布与样品间距及该截面的位置有关。通过建立三维流体力学模型,研究等温烧结过程中3个样品周围的氮气行为。结果表明,每个烧结样品沿样品长度不同横截面的孔隙分布与烧结表面附近的氮气流场密切相关。

An experimental and computational fluid dynamics (CFD) numerical study of the sintering of an Al?7Zn?2.5Mg?1Cu alloy in flowing nitrogen was presented. Three rectangular bars with dimensions of 56 mm × 10 mm × 4.5 mm each, equally spaced 2 or 10 mm apart, were sintered in one batch at 620 °C for 40 min in a tube furnace. The pore distribution in the selected cross section of sintered samples was found to be dependent on the sample separation distance and the distance from the cross section examined to the sample end. A three-dimensional (3D) CFD model was developed to investigate the nitrogen gas behavior near each sintering surface of the three samples during isothermal sintering. The variation in porosity in the cross section of each sintered sample along sample length was found to be closely related to the nitrogen gas flow field near the sintering surfaces.