This page contains a Flash digital edition of a book.
of a fi ne microstructure (specifi cally, the size of the eutectic silicon phase). In the crush-critical areas of the nodes, the castings achieve an American Foundry Society (AFS) modifi cation level between 5 and 6, indicating the aluminum’s microstructure has been fully modifi ed for highest ductility and fracture strength. T e fi neness of the silicon phase largely benefi ted the ductility of the casting. By consolidating additional com-


ponents with the redesigned nodes, Honda realized cost savings due to the reduction of tooling investment. Addi- tionally, the application of a casting in the space frame eliminated the need for MIG (metal inert gas) weld length


on each side of the vehicle, thereby minimizing thermal distortion of the space frame during construction. “T rough the ablation casting


process, Honda was able to achieve the mechanical property requirements for application in the crash zone, produce weldable and hollow node components with both thick and thin wall sections, and maintain an acceptable dimensional tolerance,” Vais said. “T is new technol- ogy was a key element to achieving the fi nal performance targets of the new NSX supercar body structure.” With the January launch of the


production version of the NSX, the nodes are one of the fi rst public real- world applications of ablation casting


and a solid example of the cutting- edge advantages ablation gives design- ers to make lightweight structural parts. “T e original Acura NSX debuted


in America 25 years ago. NSX stood for ‘New Sports Experimental.’ But when it proved to be no experiment, the name stuck. And NSX redefi ned what it meant to be a supercar,” said Mike Accavitti, Senior Vice President and General Manager, Acura Division, at the North American International Auto Show in January. “Supercar performance, delivered in a unique and challenging way, powered by new tech- nologies and utilizing new materials, that is the heritage of NSX.”


Best-In-Class


Conformable Compressed Natural Gas Tank REL Inc., Calumet, Michigan, and Eck Industries, Manitowoc, Wisconsin


Material: 7075 aluminum. Process: Low pressure casting. Weight: 71.4 lbs. Dimensions: 11.25 x 11.25 x 20.25 in. (quarter-scale model). Application: Storage of compressed natural gas on automobiles and trucks.


• This conformable tank can store 20-25% more compressed natural gas than a cylinder due to better use of the allowable packaging space.


• To store high pressure without a spheri- cal or cylindrical shape, the inner structure of the vessel must carry the load, so REL designed the tank using the Schwartz P-Surface cell design. The cell walls act as struts and carry a tensile load, keeping the tank intact.


• The tank operates at 3,600 psi yet must withstand a burst of pressure of 8,100 psi and tens of thousands of cyclical loads.


• REL teamed with Eck Industries to cast 7075 aluminum using printed sand cores and fixed walls coated with a proprietary thermal barrier technology, filled on a low pressure casting machine.


24 | MODERN CASTING April 2015


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60