(華南理工大學(xué) 國家金屬材料近凈成形工程技術(shù)研究中心，機械與汽車工程學(xué)院，廣州 510640)
摘 要: 本文制備了不同F(xiàn)e和Mn含量高真空壓鑄AlSiMgMn合金，使用透射電鏡(TEM)對富Fe相晶體結(jié)構(gòu)和成分進行了分析；使用高分辨三維X射線(3D μ-CT)對合金進行了斷層掃描，獲得了富Fe相三維形貌和空間坐標(biāo)；結(jié)合非平衡凝固相變計算，討論了Fe和Mn含量對富Fe相形成的影響，并分析了初生α-Fe相的生長機理。基于二分Kmeans和DBSCAN方法，設(shè)計了空間粒子團簇計算程序，對3D μ-CT得到的富Fe金屬間化合物進行了聚類計算，分析了其團簇定量特征。結(jié)果表明：隨著Fe含量增加，富Fe相中Fe含量增加；Mn含量增加不改變富Fe相的元素含量；兩者均不改變富Fe相的晶格常數(shù)，但大幅提高富Fe相的形成溫度；與平衡凝固相比，高冷卻速度下富Fe相和α(Al)相形成順序改變，對富Fe金屬間化合物三維特征和分布產(chǎn)生重要影響，其團簇更為緊密。
關(guān)鍵字: 高真空壓鑄；AlSiMgMn合金；富Fe相；三維形貌；團簇特征
（School of Mechanical and Automotive Engineering, National Engineering Research Center of Near-net-shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, China）
Abstract:AlSiMgMn alloys with different Fe and Mn contents were prepared with high vacuum die-casting (HVDC) process. Transmission electron microscopy (TEM) was used to analyze and compare the crystal structure and composition of the Fe-rich intermetallic in the alloys, and their three-dimensional morphology and characteristics were inspected by high-resolution three-dimensional X-ray micro computed tomography (3D μ-CT). Combined with calculation of non-equilibrium solidification process, the influences of composition and cooling rate on the Fe-rich intermetallic formation were analyzed and discussed. The growth mechanism of primary Fe-rich intermetallic was proposed. Based on the 3D coordinates of the intermetallics, two methods of bisecting, namely Kmeans and DBSCAN, were used to characterize the clusters of the intermetallics. The results show that with the Fe content increases, the Fe content in the intermetallic increases but the intermetallic lattice constant doesn’t show difference; the increase of Mn content does not change the intermetallic compositions whereas significantly increases the formation temperature of the intermetallics promoting their formation before α(Al) grains, which causes significant change of the intermetallic three-dimensional characteristics and distribution, namely the intermetallic clusters are denser.
Key words: high vacuum die casting; AlSi10MgMn alloy; Fe-rich intermetallics; three-dimensional morphology; cluster characteristics
