Wang Yunfei, Chen Wenyao, Liu Ya, Peng Haoping, Wang Jianhua, Su Xuping
Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164, China.
Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, China.
Materials (Basel). 2023 Sep 13;16(18):6188. doi: 10.3390/ma16186188.
The synergistic effect between strontium (Sr) and melt quenching on the solidified microstructure of hypereutectic Al-Si alloys was investigated by optical and scanning electron microscopy. The results indicate that melt quenching can suppress the growth of primary Si particles in the solidified structure of the hypereutectic Al-Si alloy, resulting in a significant decrease of in the average size of primary Si particles in Al-(1822)Si alloys from 30.3566.31 μm to 15.13~34.63 μm. The synergistic effect between Sr and melt quenching can further inhibit the precipitation of primary Si particles in the Al-18Si alloy. After the addition of Sr to Al-18Si alloy and undergoing melt quenching, the area fraction of primary Si clearly decreases. When the added amount of Sr increases from 0.1 wt.% to 0.5 wt.%, the area fraction of primary Si decreases from 1.13% to 0.16%. With 0.5 wt.% Sr in the tested alloy, the inhibiting effect on primary Si precipitation was significantly improved. Research has shown that the cooling rate has a significant impact on the solidified structure of the melt-quenched Al-18Si-0.5Sr alloy. There exists no primary Si in solidified structures on the area of 1/8R and 1/4R from the surface of the round bar sample, but the area fraction of primary Si increases, respectively, to 1.97% and 12.48% on the area of 1/2R and R from the surface. The higher the cooling rate, the higher the inhibitory effect on the primary Si precipitation in the Al-18Si-0.5Sr alloy.
通过光学显微镜和扫描电子显微镜研究了锶（Sr）与熔体快冷对过共晶Al-Si合金凝固组织的协同作用。结果表明，熔体快冷可抑制过共晶Al-Si合金凝固组织中初生硅颗粒的生长，使得Al-(1822)Si合金中初生硅颗粒的平均尺寸从30.3566.31μm显著减小至15.13~34.63μm。Sr与熔体快冷的协同作用可进一步抑制Al-18Si合金中初生硅颗粒的析出。向Al-18Si合金中添加Sr并进行熔体快冷后，初生硅的面积分数明显降低。当Sr的添加量从0.1 wt.%增加到0.5 wt.%时，初生硅的面积分数从1.13%降至0.16%。在所测试的合金中添加0.5 wt.%的Sr时，对初生硅析出的抑制效果显著提高。研究表明，冷却速率对熔体快冷的Al-18Si-0.5Sr合金的凝固组织有显著影响。在圆棒试样表面1/8R和1/4R区域的凝固组织中不存在初生硅，但在表面1/2R和R区域，初生硅的面积分数分别增加到1.97%和12.48%。冷却速率越高，对Al-18Si-0.5Sr合金中初生硅析出的抑制作用越强。
