Perfecting the Process

June 4, 2004
Ashlands sand-core modeling software manages variables, analyzes effects, and predicts core density ? so its possible to estimate casting quality.

Some experts know the metalcasting process through and through. Others are adept at computer programming. Increasingly, their skill areas are merging. Software is opening up new dimensions for metalcasting — in product design and, particularly, in process development. Because it coordinates data effectively and tests theories efficiently, modeling software speeds through development stages and shortens trial periods.

Ashland Casting Solutions’ Arena-flow software has been commercialized for almost two years, and the response of foundries and OEMs worldwide has been enthusiastic. Among notable users to date are Caterpillar, Ford Motor, General Motors, Hydro Aluminium, and Nissan.

Core technology — First developed by Arena-flow L.L.C., Ashland offers it specifically for sand-core manufacturing. It models all the fluid and granular-flow behavior that defines sand-core blowing, varying the parameters and conditions to optimize tooling design for the best results. All this is done on a desktop computer, saving the time and cost of multiple iterations toolmaking typically requires.

The engineer uses Arena-flow’s graphic user interface to import CAD drawings and indicate all the variables in the core-filling process. He or she sets air-flow and pressure conditions; evaluates sand magazine designs; locates and sizes blow tubes, chooses vent locations, sizes, types, and resistance; specifies sand, additives, and catalysts; and selects gassing and purging parameters.

Arena-flow software models both the sand and air phases of coremaking. It shows 3D multiphase computations and accurately simulates air and sand-particle flow. It will analyze well over 3 million sand particles discretely, and show interfacial drag coupling of air and sand particles. It ensures “proper wall restitution,” says Mark Adamovits, Casting Solutions’ CAE/rapid-prototyping manager, “to ensure accurate particle deflections off of tooling surfaces.” And, it determines the point at which the sand reaches maximum density.

Arena-flow’s analysis functions cover the entire core-blowing machine and process. It rotates, zooms, and slices views it portrays. It analyzes coremaking variables (particle-volume fraction, core density, pressure) and additional variables (particle velocity, air velocity, vent/blow tube performance).

According to Adamovits, the software continues to develop. Newer functions are being developed to make Arena-flow “very predictive of core density,” Adamovits says. “And, from that data, it’s possible to draw information about the quality of castings that are to be produced.” These later developments are based on the early commercial placements of Arena-flow, as well as on Ashland’s ongoing research. Some of these results — from an application at Nissan — will be reported in a presentation later this month at the Japan Foundry Engineering Society conference, May 23-25, in Nagoya, Japan.

Designed to serve — There are advances in marketing Arena-flow, too. First available to foundries and OEMs through licensing agreements, Ashland now acts as a service provider, as well. As many foundries operate within strict capital and operating budgets, potential users now can turn to Ashland with a specific process-design request. According to the task presented, a project team will be organized, the case studied, the possible approaches analyzed, and a quote prepared.

The potential for Arena-flow is vast, according to Adamovits, because the software code is rooted in “pure physics.” It could be applied in a range of applications that includes lost-foam pattern making, fluidized-bed processes, segregation of sand and additives, and shot blasting, he suggests. Ashland’s current and future plans include some of these applications. However, its working relationship with the software’s developers, Arena-flow LLC, is currently focused on all dimensions of sand casting. Enhancements to the Arena-flow software package are underway, and are expected to be revealed in the coming weeks.