SOLUTIONS: Process

PROCESS DESIGN:

Grenville Castings Ltd uses cutting edge computer technology to aid in the design of our customer's molds and our casting process.

Finite Element Solidification Analysis (EKK) and Fluid Flow Modeling.
Solid and Surface Modeling, using Unigraphics, Solid Edge, Cadkey and exchange formats
We combine these technologies with metallurgical engineers and experienced foundrymen in an effort to design optimum processes and industry leading product quality and delivery.

PROCESS CONTROL:

Grenville Castings Ltd has developed their own computerized process control system for our Low Pressure casting process. We employ real time process monitoring and control for:

Multi zone mold temperature -for process control
Metal Temperature - minimized for best properties
Water and Air Cooling Temperature - for consistent gradient across molds
Process Air Dew Point -to minimize regassing of metal
Process Air Pressure Curves -for fill rate control and leak detection

We can download process parameters directly from our central quality database and upload process data in order to record process trends and history. Machine alarming for water line restriction and machine based part serialization make the machines industry leading technology. This process control system allows us to produce the repeatable product integrity demanded by present and future casting customers.

LOW PRESSURE CASTING:

Low Pressure is the process of choice, offering higher casting yield, more repeatable quality, higher productivity, and opportunities for higher casting integrity with the use of water chilling. In combination with FEA Solidification analysis, the Low Pressure casting process is ideally suited to high strength automotive components as well as a wide array of other products.

Low Pressure Casting

Uses air at a low pressure (3-4 psi) to feed metal against gravity into a mold and hold it there until solidification is complete.

click here to view the advantages of the GCL Low Pressure process

GRAVITY POUR PERMANENT MOLD:

Over the years, Grenville Castings has tailored the permanent mold process to accommodate many difficult casting shapes. This allows us to be very competitive producing castings that our competitors can not successfully produce. The use of a combination of sand cores, moving steel cores, and loose cores is commonplace. We use our solidification and fluid flow software to optimize feed and runner systems.

CASTING PROCESS QUALITY AND ITEGRITY

Today's high strength aluminum castings have to meet strict strength requirements and in many cases must meet high fatigue requirements. Automotive suspension castings and motor mounts undergo high levels of cyclical loading and must maintain strength through the life of the vehicle.

Casting defects from oxide films and voids due to shrinkage and gas must be taken seriously. Solidification computer modeling and metal degassing ensure that our castings are pore free. This is confirmed with real time radioscopic analysis. Metal degassing and fluxing remove oxide and gas void potential. We couple these process practices with metal filtration to guarantee our customers and ourselves the best possible final product.

Final metal quality is controlled with strict adherence to metal modification, grain size reducers and metal composition give mechanical results required for high strength castings susceptible to fatigue and high impact potential.

METALLURGICAL QUALITY:

Complete metallurgical laboratories with spectrochemical analysis, real time radioscope, metal polishing and optical microscopes support our entire operation. Mechanical Testing of casting properties is verified with a Tensile tester and results are analyzed for statistical process control and batch verification.

HEAT TREATMENT:

Grenville Castings uses modern accurate heat treat equipment to achieve repetitive consistent properties. Batch style furnaces ensure minimal time to quench for optimal properties. Our quench baths are heated recirculating quench tanks to give consistent quench quality throughout the batch. Batch heat treat quality is confirmed with mechanical and brinell testing.