The purpose of this paper is to evaluate the effect of post process combinations, e.g. hot isostatic pressing (HIP) only, HIP + T6 heat treatments, and T6 only, with different aging time, on surface properties, microstructure and mechanical properties of stress-relieved AlSi10Mg parts produced by direct laser metal sintering.,HIP process and HIP + T6 heat treatments were applied to as stress-relieved direct laser metal sintered (DMLS) AlSi10Mg parts. Aging times of 4 and 12 h are selected to examine the optimum duration. To analyze the advantages of HIP process, a T6 heat treatment with 4 h of aging was also applied. Densities, open porosities and roughness values of as stress-relieved, HIPed, HIP + T6, and T6-only samples were measured. The samples were characterized by OM and SEM together with EDX analysis. An image analysis study was made to evaluate the inner pore structure, thereby to understand the mechanical behavior.,HIP process does not cause a significant change in surface porosity; yet it has a positive influence on inner porosity. HIP process results in a microstructure of the aluminum matrix surrounded by a network of micron and nano size Si particles. Additional heat treatment results in larger particles and precipitation. After HIPing, ductility increases but strength decreases. Samples aged 4 h present improved yield and tensile strength but decreased elongation, yet samples aged for 12 h reach a combination of optimum strength and ductility. The lower level of tensile strength and ductility in T6-only condition indicates that HIP process plays a crucial role in elimination of the porosity thus improves the effectiveness of subsequent heat treatment.,The study investigates the effect of post-process conditions and optimizes the aging time of the T6 heat treatment after HIP process in order to obtain improved mechanical properties. The stress-relieved state was chosen as the reference to prevent distortion during HIPing or heat treatment.

中文翻译：

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HIP工艺及后续热处理对直接金属激光烧结AlSi10Mg合金组织和力学性能的影响

本文的目的是评估后处理组合，例如仅热等静压 (HIP)、HIP + T6 热处理和仅 T6，不同时效时间对表面性能、微观结构和应力机械性能的影响。通过直接激光金属烧结生产的释放的 AlSi10Mg 零件，HIP 工艺和 HIP + T6 热处理应用于作为应力消除的直接激光金属烧结 (DMLS) 的 AlSi10Mg 零件。选择 4 小时和 12 小时的老化时间来检查最佳持续时间。为了分析 HIP 工艺的优势，还应用了时效 4 小时的 T6 热处理。测量了应力消除、HIPed、HIP + T6 和仅 T6 样品的密度、开孔率和粗糙度值。样品通过 OM 和 SEM 以及 EDX 分析进行表征。进行图像分析研究以评估内部孔隙结构，从而了解力学行为。HIP 过程不会引起表面孔隙率的显着变化；但它对内部孔隙率有积极的影响。HIP 工艺导致铝基体的微观结构被微米和纳米尺寸的硅颗粒网络包围。额外的热处理会导致更大的颗粒和沉淀。HIPing 后，延展性增加但强度降低。老化 4 小时的样品表现出提高的屈服强度和拉伸强度，但降低了伸长率，但老化 12 小时的样品达到了最佳强度和延展性的组合。T6-only 条件下较低的拉伸强度和延展性水平表明 HIP 工艺在消除孔隙率方面起着至关重要的作用，从而提高了后续热处理的有效性。,该研究调查了后处理条件的影响并优化了时效HIP 工艺后 T6 热处理的时间，以获得改善的机械性能。选择应力消除状态作为参考，以防止 HIP 或热处理过程中发生变形。