Cast Body Nodes for 2016 Acura NSX

Ablation casting is an emerging technology which combines traditional sand molding techniques with rapid cooling due to the use of a water soluble binder. High cooling rates and control of solidification direction allows for exceptional mechanical properties and complex shapes. Through the use of ablation, six different body node castings have been manufactured for the 2016 NSX aluminum space frame. The high mechanical properties allowed these castings to be integrated into the crash structure for energy absorption. Using the traditional casting alloy A356, target mechanical properties were 190 Mpa Yield Strength, 280 Mpa Tensile Strength and 12% min elongation. The high elongation was achieved due to the refined eutectic microstructure produced by high cooling rates. The eutectic microstructure produced by ablation was found to be Level 5 or 6 on the AFS scale. Light weighting could also be achieved when compared to traditional GDC castings. By using sand molds instead of steel dies, the nominal wall thickness was set to 4 mm instead of 5-6 mm when using traditional gravity die casting. Further light weighting was achieved by using sand cores to create complex hollow internal sections. The combination of high properties and hollow shapes made ablation cast nodes ideal for a lightweight space frame structure.