In the foundry industry, process improvements move slowly and methodically into the future. This is not the case in the world of computer simulation. So much has changed in even the last few years that it is impossible to contain enthusiasm for this dynamic industry.

Take, for example, the computers foundries are using today. Just three short years ago, many foundries were running their casting process simulations on Unix workstations, These more than $30,000 machines were the only way to analyze the filling of a mold cavity using the NavierStokes equations. Foundries not only had to buy these expensive machines, they also had to employ people who could "speak" the Unix language. Talk of moving to PC's for these types of filling analyses was just beginning in 1999, the last time MODERN CASTING offered a casting process modeling software round-up ("1999 Casting Simulation Software Survey," May 1999).

Now, the PC conversion is complete. Unix workstations are no longer considered the only option when purchasing a computer to run a conventional casting process simulation package. In fact, today's machines generally consist of 2GB of RAM, dual processors and 2GHz of processing speed, and can be purchased for less than $6000. Some of these new machines can run 20-30 times faster than the equipment common in the industry six years ago. A complicated filling and solidification job that used to run overnight can be completed in one hour. That's progress, and it is only going to improve.

More Power, New Capabilities

But speed and platform changes are not the only buzz in the world of computer simulation. The programs themselves have become more powerful and have added many new features.

Nearly all of the casting process modeling software packages on the market today incorporate filling analysis along with the solidification solution. Traditionally, filling is simulated most accurately using the fully coupled Navier-Stokes equations and an appropriate turbulence model. Many software programs utilize this approach, while other packages have either developed a simplified Navier-Stokes equation, or simply use Bernoulli approximations to simulate metal flow.

Another improvement over the last three years has been in the development of material property data and interfacial heat transfer coefficients. Material property thermal data is the lifeblood of any simulation program. Simply put, bad data equals bad results.

During the last three years, thermal datasets have been developed for various metal alloys (including aluminum, steel and compacted graphite iron), mold materials and feeding systems (see this article's For More Information box and the August Website-Only Article., at www.moderncasting.com). Another development involves the work done to understand the fluid mechanics of filters. Pressure drop data has been developed for pressed, extruded and reticulated foam filters, and this data is easily available in industry literature. Many programs allow for input of the pressure drop data, which then permits the user to predict the flow rate through the filter more accurately. This leads to accurate fill time and flow characteristic predictions.

Major enhancements to various programs have opened the door to modeling other processes important to foundries. For example, it is now possible to model the heat treatment process using the results from the filling and solidification analysis. Metallurgy predictions can be made, as well as the impact on the structural integrity of the part. The lost foam process now is being modeled in several programs, although much work must be done to develop the data necessary to provide accurate results. In addition, modeling of the sand core blowing process has just been introduced.

And finally, some software vendors have capitalized on the concurrent development of optimization techniques and incorporated this technology into their programs. At first glance, this allows the user to let the computer help optimize such things as riser placement and size and chill locations. However it isn't hard to imagine that this is just the beginning, and that we are about to embark on a journey in which casting process simulation programs soon will perform what is unthinkable today.

What this all means is that computer simulation can help foster the success and viability of the foundry industry for many years to come. The more capability and accuracy that is built into our simulation tools, the better, more efficient castings that can be produced. As the closest production method to "near net shape," there is no reason that the industry can't steer the reemergence of cast products as the preferred production method.

Editor's Note: The following survey was compiled to provide details on the latest features of casting simulation software. Each description includes a success story of how a particular program has optimized a foundry's casting operation.

Mavis Software

Alphacast Software, Ltd.

2 Kimble Close

Northampton

NN4 ORF

England

44 1604 674716, Fax: 44 1604 660476

Website: www.alphacast-software.co.uk

Email: sales@alphacast-software.co.uk

Contact: Cliff Jobson.

General Methodology: Finite difference mesh.

Software Features: Solid models can be generated from drawings using the integral modeler, or from ASCII .STL files. Each version includes a weight estimator, casting simulation and full post-processing (color coded contour plots and simulated x-ray format). Prediction capabilities include temperatures, pressures and velocities during filling, freezing times, macro and microshrinkage distributions, Niyama coefficients, local freezing times, primary dendrite arm spacings (Al alloys), steady-state die temperature distributions, mold temperatures, cooling rates and temperature gradients.

Process Applications: Sand, investment, permanent mold low-pressure and permanent mold diecasting.

Computer Platform: PC with Windows.

Installations: 36 total, including Copal Casting, Birmingham, England; Siobra Arbois, Arbois, France; Brafe Engineering, Woodbridge, England; and Materials Ireland, Dublin, Ireland.

Training, Support and Update Options: Onsite training courses use customer parts for analysis. Technical software support is supplied on an annual basis and includes software updates. Packages also can be rented on an annual basis, including technical support and software updates.

Case History: A zinc high-pressure diecasting tool at Siobra Arbois, Arbois, France, produced castings with 20-30% rejects due to surface porosity revealed after painting. Simulation showed a poor filling profile for the part and significant air entrapment, and then was used to analyze alternative gating designs to improve the part quality. A single ingate with two overflows was predicted to give a progressive fill with minimal air entrapment. The tool was modified based on the simulation and subsequently commissioned. The parts are now produced with zero rejects after painting.

Select No. No. 201 at www.moderncasting.com/info

CastCAE 4.0

CT-Castech, Inc. Oy

Kantokatu 7

04200 Kerava

Finland

358-9-2344482, Fax: 358 9 2344492

Website: www.castech.fi

Email: sales@castech.fi

Contact: Niko Turunen.

General Methodology: Finite volume mesh.

Software Features: Molds and shells are created through mesh generation--no CAD program is needed. Solidification calculations can be based on metal, mold, chill, core and insulation domains. The software also calculates shrinkage and expansion and the effects of exothermic riser sleeves and coatings, as well as performing a 3-D view of x-ray visualization.

Process Applications: Sand and diecasting.

Computer Platforms: PC with Windows NT and higher and Macintosh.

Installations: More than 100 licenses sold, including AlumAlloy Co., Inc., Ontario, California.

Training, Support and Update Options: Training (usually performed onsite) and support are included for the first 12 months for new customers, including updates. After the first year, customers are encouraged to sign up for the valid maintenance agreement, which offers support and upgrades.

Case History: AlumAlloy Co., Inc., an aluminum sand casting foundry in Ontario, California, had an order for a 50.2-in-diameter aluminum ring 6.7 in. thick. Concerned about creating a sound casting, the foundry simulated the casting process first to verify riser size and placement.

The Castech software simulated one quarter of the component (ring symmetry assumes the same results for each section) and saw that the chill placed beneath the casting would direct solidification towards the risers. The risers fed 32% of their total volume into the casting and contained the casting's only porosity and shrinkage defects, verifying that a sound casting would result.

Select No. 202 at www.moderncasting.com/info

EKK, Inc.

100 North Pond Drive, Suite A

Walled Lake, MI 48390

248/624-9957, Fax: 248/624-7158

Website: www.ekkinc.com

Email: ekk@ekkinc.com

Contract: Marty McLaughlin.

General Methodology: Finite element analysis.

Software Features: Kent software capabilities include a multiple surface finite element mesh generator. The Wrafts program features a Navier-Stokes equation solver, which also can be adapted to semi-solid molding and can perform heat transfer simulation. CAP offers heat transfer analysis for performing solidification and multicyclic analysis. PORO porosity prediction software can predict porosity growth in aluminum and iron castings.

Process Applications: Vertically-parted green sand, permanent mold and diecasting, as well as semi-solid molding.

Computer platforms: Linux or Unix platforms.

Installations: Currently more than 20 licenses, including installations at Internet Corp., Troy, Michigan, Hayes Lemmerz, Inc., Ferndale, Michigan, and ACP Manufacturing Co. LLC, Blossburg, Pennsylvania.

Training, Support and Updates: Customers are offered one week of initial training, covering the basic tutorial and a unique project from their company. Customer support includes unlimited phone and email support and software updates.

Case History: Hayes-Albion, Albion, Michigan, approached EKK to help solve a gate shrinkage problem in a transmission case casting. EKK performed a porosity analysis based on flow with conjugate heat transfer and solidification. The porosity analysis predicted porosity exactly where the actual problem was occurring. An alternative gating design was suggested and verified by the software. The original porosity problem disappeared.

Select No. 203 at www.moderncasting.com/info

PAM-Cast

ESI North America

13399 West Star

Shelby Township, Michigan 48315

586/323-4610, Fax: 586/323-4611

Website: www.esi-group.com

Email: info@esidetroit.com

Contact: Buzz Sanderson.

General Methodology: Finite difference and finite element methods.

Software Features: The software performs filling, temperature distribution and solidification 'using mesh generation. It also can predict residual stresses, strains and displacement, and can be coupled with other software to predict performance criteria such as fatigue life.

Process Information: Gravity and low-pressure permanent mold, high-pressure diecasting, sand, investment, thixomolding and squeeze, lost foam and contrapressure casting.

Computer Platforms: PC with Windows NT and higher and Unix.

Installations: More than 30, including 'at major automotive OEM's and large-scale foundries such as PSA; Rungis, France; Renault, Paris; and Dasalt, Pairs.

Training, Support and Update Options: PAMCast is supported by a network of ESI offices throughout the world. Training is available 'either at ESI facilities or may be tailored and delivered onsite to fit specific customer needs.

Case History: Montupet, Quebec, Canada, an automotive gravity and low-pressure permanent mold foundry, uses PAM-Cast software to simulate large parts that require several million computational cells. By using the software, the foundry can shorten lead times, and eliminate defects before a die is built, This results in time savings of up to two months. Based on its sucdess with initial components, the foundry now simulates 100%' of the components it casts.

Select No. 204 at www.moderncasting.com/info

Solidcast, Opticast and Flowcast

Finite Solutions, Inc.

4769 Highland Park Drive

Slinger, WI 53086-9441

877/644-0785, Fax: 262/592-0044

Website: www.finitesolutions.com

Email: Dave@finitesolutions.com

Contact: David Schmidt.

General Methodology: Finite difference, multi-variable response surface and a CFD-based method.

Software Features: Heat transfer is calculated through the finite difference method, and simultaneous volumetric calculations also are performed to track the formation of macroporosity during solidification. Simulations can be set to find optimized results. Detailed information also can be obtained about temperature, velocity and pressure during the filling process.

Process Applications: Sand, investment and permanent mold casting.

Computer Platforms: PC with Windows 98 and higher.

Installations: Over 420 companies and schools worldwide. Users include Stahl Specialty Co., Kingsville, Missouri; Harrison Steel Castings Co., Attica, Indiana; Signicast Corp., Milwaukee; and Bimac Corp., Dayton, Ohio.

Training, Support and Update Options: Three-day training classes are offered every two months. Full phone, fax and email support are included at no charge for the first year, and updates are free during that time. Continuing use/support/update contracts are available on a yearly fee basis after the first year. Updates and an online user group can be found through Finite Solutions' website.

Case History: Johnson Matthey, Ltd., St. Catharines, Ontario, Canada, an investment casting foundry, was encountering problems with oxide inclusions and gas defects in the production of a stainless steel casting. These defects typically are associated with high velocity and turbulence during filling. Flow modeling of the original gating configuration showed excessive velocities in the casting when the shell was 30% full. The revised design showed much lower fluid velocities and a more even filling of the shell, significantly reducing turbulence and gas entrainment/oxide formation.

Select No. 205 at www.moderncasting.com/info

Flow-3D

Flow Science, Inc.

683 Harkle Road, Suite A

Santa Fe, NM 87505

505/982-0088, Fax: 505/982-5551

Website: www.flow3d.com

Email: cfd@flow3d.com

Contact: Tom Jensen.

General Methodology: Finite difference code.

Software Features: The software automatically couples the grid with geometry and offers multi-block gridding, including embedded and linked blocks. Special options include solidification shrinkage, binary segregation during solidification, surface defect tracking, specification of coherency and rigidity solid fractions.

Process Applications: Sand, die, lost foam, tilt pour permanent mold, centrifugal and semi-solid casting as well as limited applications in investment and continuous casting.

Computer Platforms: Various PC's and Linux.

Installations: More than 500 worldwide, including Ford Motor Co., Dearborn, Michigan; General Motors Corp., Warren, Michigan; and Amcan Castings, Ltd., Hamilton, Ontario, Canada.

Training, Support and Update Options: Training is available every other month at Flow Science's office. Technical support and software upgrades are provided during the first year after the purchase of a permanent license and on an annual basis as a maintenance agreement for holders of permanent licenses.

Case History: Ford Motor Co., Dearborn, Michigan, depends on diecasting for many of its automotive components but must watch for surface defects. Using Flow 3-D software helps determine whether the molten metal is taking a direct route through the cavity or is swirling around, causing early solidification and oxide inclusions. Surface defect tracking predicts the formation and location of oxides, leading to optimized reservoir and gate positioning and sizing. Making these design changes on the simulation software eliminates expensive die modification.

Select No. 206 at www.moderncasting.com/info

Magma Foundry Technologies, Inc.

2340 South Arlington Heights Road

Arlington Heights, Illinois 60005

847/427-1001, Fax: 847/427-0601

Website: www.magmasoft.com

Email: sales@magmasoft.com

Contact: Tim McMillin.

Software Features: Alloy-specific simulation, including calibration.

Process Applications: Sand, shell, investment, permanent mold and diecasting.

Computer Platforms: All.

Installations: More than 700, including Grede Foundries, Milwaukee; Waupaca Foundry, Waupaca, Wisconsin; Stahl Specialty Co., Kingsville, Missouri; and Atchison Casting Corp., Atchison, Kansas.

Training, Support and Update Options: Magma provides foundry-experienced engineers, not software developers, for training and implementation to assure that its tools will be further developed and supported well into the 21st century.

Case History: St. Cloud Foundry (Grede Foundries, Inc.), St. Cloud, Minnesota, was experiencing difficulty obtaining good directional solidification in an iron off-road vehicle hub it was casting in green sand. The difficulty was due to the gating design and use of ductile iron. Through the use of Magmasoft and the predictive tools specific to iron, the foundry was able to visualize the porosity problem and determine the best solution. The simulation tool also helped the foundry predict mechanical properties of the iron for consistency in hardness and elongation strength. This ensured a sound, cost-effective casting was delivered to the OEM.

Select No: 207 at www.moderncasting.com/info

NovaCast AB

NovaFlow & Solid

Softcenter

SE-372 25 Ronneby Sweden

216/328-8384, Fax: 216/328-8387

Website: www.novacast.se

Email: bhaskaran@globemetallurgical.com

Contact: Charles Antony Bhaskaran.

General Methodology: Finite difference method/volume of fluid.

Software Features: Software includes separate modules for 3-D import, initial settings and auto mesh, flow with heat transfer, fully coupled flow, and solidification and calibration. Simulations can be viewed by temperature, liquid, shrinkage, solidification time, thermal modulus, flow rate, and 2-or 3-D sections visualized in rotation, pan, zoom, 3-D, 2-D, slicing and flow directions.

Process Applications: Sand (horizontal and vertical), investment, permanent mold, shell and diecasting.

Computer Platforms: PC with Windows 95 or higher and Linux.

Installations: More than 200 users, including Advanced Cast Products, Inc., Meadville, Pennsylvania; Grede Foundries, Inc., Milwaukee; Lufkin Industries, Inc., Lufkin, Texas; and Wisconsin Precision Casting Co., East Troy, Wisconsin.

Training, Support and Update Options: Training is carried out onsite or at training centers. Support is offered by local representatives and through the head office in Sweden. Update of the program is once a year or more for all users with a valid technology partner agreement, which runs for 12 months at a time.

Case History: Advanced Cast Products, Inc., Meadville, Pennsylvania, experienced a problem with widespread elephant skin surface defects on a 2-on vertically molded job. Simulation showed highly exposed broken stream metal flow down the riser. Also, oxidized metal was entering the mold cavity first. By heavily tapering the sides of the ingate and the end of the runner, the falling metal converged into a solid stream. The initial metal to enter the system then was contained in a catch basin at the bottom of the riser, solving the problem.

Select No. 208 at www.monderncasting.com/info

Simtec Simulation Software

Simatec, Inc.

3663 Broadmoor SE

Grand Rapids, MI 49512

616/975-3882, Fax: 616/975-7775

Website: www.simtec-inc.com

Email: info@simtec.inc.com

Contact: Don Wade.

General Methodology: Finite elemental analysis.

Software Features: Simulates mold fill and solidification to predict flow-related defects. Performs solidification analysis and can predict defects including shrinkage cavities, hot tearing, segregation and residual stress.

Process Applications: Sand, die, permanent mold, investment, lost foam, semi-solid, squeeze and centrifugal casting.

Computer Platforms: PC with Windows 95 or higher and Linux.

Installations: More than 250 worldwide, including Mercedes, Germany; Lioho, Taiwan; and Progress Casting Group, Inc., Plymouth, Minnesota.

Training, Support and Update Options: Training (5 days recommended) can be performed onsite. Customer support response network includes email and telephone contacts for software specialists. Updates are released once or twice each year and are automatically sent to all current software users.

Case History: Metal Castings, a die caster in the UK, was producing an AZ91 magnesium cylinder head cover for Ford Motor Co. The foundry was experiencing a high defect rate due to leakers in the high mass oil flow areas. Simtec software developed a casting technique that enlarged the gating system and added cooling to the critical areas. By increasing the gate area, the feeding was optimized to avoid shrinkage. Together with two additional cooling lines in the critical areas where hot spots occurred, the homogenization of temperature distribution created a smooth solidification gradient, which resolved the high scrap rate problem.

Select No. 209 at www.moderncasting.com/info

Procast

UES Software, Inc

175 Admiral Cochrane Drive

Annapolis, Maryland 21401

410/573-2037, Fax: 410/573-2041

Website: www.ues-software.com

Email: sales@ues-software.com

Contact: John Barney.

General Methodology: Finite element.

Software Features: Software includes free surface flow, stress and distortion calculation, microstructure evolution with mechanical property determination, porosity and trapped gas predictions. Integrated alloy property prediction program is based on specific chemistry.

Process Applications: Sand, shell, low pressure permanent mold diecasting, semi-solid, gravity permanent mold, lost foam, investment, squeeze, continuous and centrifugal casting.

Installations: More than 400, including Gould Pumps, Ashland, Pennsylvania; Precision Castparts Corp. Portland, Oregon; and Citation Corp., Southfield, Michigan.

Computer Platforms: PC with Windows 2000 or higher, Unix and Linux.

Training, Support and Update Options: A three-day training class is offered every month and in-house training also is available. Technical support personnel have foundry, computer software and CAD experience. Upgrades are downloadable from .ftp site.

Case History: ITT Industries-Gould Pumps, Ashland, Pennsylvania, wanted to optimize existing designs for a pump line to improve yield and reduce machining time using ProCast software. The pump casing originally employed nine risers to address locations that produced porosity. After running a pouring simulation, the foundry realized only five problem areas existed. After modifying the design by using only five risers to feed the potential problem areas, the simulation resulted in a sound casting and the design was implemented into production with no further changes. The new design achieved a 29 lb/casting reduction in pour weight and an 18 sq in. reduction in machining area.

Select No. 210 at www.moderncasting.com/info

For More Information

Visit www.moderncasting.com for the 2002 AFS Transaction paper, (02-080) "Mold Material Thermophysical Data," T. Midea and J. V. Shah (2002).

About the Authors

Tony Midea is a product development manager in charge of the casting simulation group at Foseco, Inc. He is an aerospace engineer by trade (B.S. and M.S. in aeronautical and astronautical engineering from Ohio State Univ. and Univ. of Illinois, respectively) and has been involved with computer simulation activities for the past decade. The AFS Process Design & Modeling Committee (1-F) promotes computer simulation and its application in the solidification, reheating and cooling of castings.