To improve our understanding of prehistoric casting methods and materials, simulations for copper arsenic (As-Cu) alloys with up to 15 wt.% As were calculated. Cooling curves and the secondary dendritic arm spacings (SDAS) for the alloy were plotted and calculated, respectively, under non-steady-state conditions with a time-stepping procedure for prehistoric mold materials (e.g., quartz sand, sandstone, terracotta, and steatite). The cooling and microstructure of the alloy was also simulated in iron molds for immediate comparison with as-cast microstructure. The microstructure and SDAS of the as-cast alloys were studied and measured in polished samples with a metallographic microscope. The purpose of this research was to improve our ability to retroactively evaluate the influence of mold materials on as-cast microstructures and determine their materials. This article focuses on As-Cu alloy microstructure and SDAS values, and also discusses the phenomenon of “inverse segregation” and its relation to cooling rate and As concentration.

中文翻译：

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砷铜铸造模拟：对史前金属生产和材料的新见解

为了加深我们对史前铸造方法和材料的理解，我们计算了砷含量高达 15 wt.% 的铜砷 (As-Cu) 合金的模拟。在非稳态条件下，对史前模具材料（例如石英砂、砂岩、赤陶和滑石）使用时间步长程序分别绘制和计算合金的冷却曲线和二次枝晶臂间距 (SDAS) ）。合金的冷却和微观结构也在铁模中模拟，以便与铸态微观结构进行直接比较。用金相显微镜对抛光样品中的铸态合金的微观结构和 SDAS 进行了研究和测量。这项研究的目的是提高我们追溯评估模具材料对铸态微观结构的影响并确定其材料的能力。本文重点介绍 As-Cu 合金的显微组织和 SDAS 值，并讨论了“逆偏析”现象及其与冷却速度和 As 浓度的关系。