Mechanical integrity and erosion resistance of 3D sand printing materials

[Display omitted] •Interconnections have been investigated between the organic binders and activators how to degrade and erode mechanical integrity of 3D sand molds, demonstrating microstructural visualization, mechanical integrity, and erosion resistance.•3D-printed sand molds, fabricated using a binder 2 wt% and activator of 0.25 wt%, possess flexural strength over 4 MPa, where using micro-CT analysis confirm that the molds have highest erosion resistance of 85% after poring cast steel.•Defect-free exhaust manifolds are developed based on the composition of the molds, where performance of turbo charger fabricated by 3D-printed sand mold shows better power performance of 1% compared to the genuine parts. 3D sand printing, a binder jetting-based additive manufacturing process, can directly produce sand molds with complex geometries for high-quality and lightweight metal parts. However, there is still a lack of information on how to degrade and erode the mechanical integrity of 3D sand molds. Here, correlations have been investigated between 3D printing materials and various properties of 3D-printed molds: microstructure, flexural strength, reliability, and erosion resistance. As a result, given the mechanical strength and the formation of the binder necks, the most appropriate flexural strength of 4.2 MPa, reliability of 7.8, and high erosion resistance of 86% are achieved from the 3D-printed sand molds prepared with a binder of 2 wt% and an activator of 0.25 wt%. The exhaust manifold casted using a 3D-printed sand mold with optimum conditions, it shows the same or better performance than the genuine part.