Honda of America revealed the results of its ablation casting capability with the unveiling of the new Acura NSX hybrid vehicle. The introduction took place at SAE World Congress in Detroit this month; Tom Murphy of FoundryMag.com’s affiliate WardsAuto.com reported details.
The NSX will be the world’s first vehicle to incorporate aluminum parts produced by ablation casting as large ultra-rigid nodes or junction points within the crush zones of the vehicle body. The ablation-cast nodes will have sockets into which aluminum extrusions will be inserted and then MIG-welded as part of the spaceframe.
Ablation casting, a process developed by Alotech Limited, involves sand casting followed by high-powered water-jet cleaning, with the water also acting to speed cooling of the casting. WardsAuto reported that Honda chose the ablation process because conventional sand castings would have been too brittle to deliver the required energy absorption characteristics needed in the vehicle’s spaceframe.
“Ablation casting was a key concept in order to produce this spaceframe,” Ted Klaus, chief engineer and NSX global development leader for Honda R&D Americas, stated at SAE World.
The ablation castings also allow Honda to use traditional aluminum castings at other strategic locations in the spaceframe and as the primary mounting points for suspension and power-unit components. “Without being able to apply castings at all the suspension points, we couldn’t produce a body this rigid,” Klaus said.
Shawn Tarr, principal engineer and Acura NSX body development leader, is credited advocating the use of ablation casting. He noted that the sand binder is water-soluble – which “allows the sand to get out of the way really fast, so then the water can quench the part.”
Tarr said Honda chose an aluminum spaceframe instead of a carbon-fiber monocoque to simplify the Acura NSX’ repairability.
The ablation castings and extrusion members “were designed in a way that you can extract those by removing the MIG-welds, and then we have a service part, a front clip, that would be replaced entirely,” Tarr said.
Dealers will be trained to do the work. “It’s a very strong concept so the customer doesn’t have to go to some independent shop,” Klaus says. “They will go to an authorized shop to have these high-quality repairs done, which is a real challenge in the supercar market today.”