Process
Casting
DESIGN FOR MANUFACTURE
Harrop Casting Technologies promote principles of design for manufacture (DFM). Harrop is committed to providing you with the very best expert advice and support.
Focus is on assisting you to develop and refine your casting design to obtain the highest quality cast product for the lowest possible cost.
Pattern tooling is a crucial investment that must be considered carefully and in conjunction with the casting design.
Metal casting simulation (MAGMASOFT) is regularly employed by Harrop Casting Technologies as a valuable tool in providing important insights to the liquid metal flow during mould filling, solidification sequence and porosity predictions which will inform aspects of the final casting design for manufacture.
Potential casting defects can effectively be designed out before pattern tooling is even manufactured.
Not all cast parts warrant a high-level investigation, therefore general advice regarding application of draft, split lines, material properties, heat treatment options etc. are freely available to help support you.
PATTERN TOOLING MANUFACTURE
Traditional pattern making is a process of making a ‘model’ of a part to be cast. The pattern is effectively a replica of the cast part to be produced but with shrinkage, draft and machining allowances added along with gating and feeders needed to pour molten metal into the mould.
Traditionally a Pattern Maker will cut and shape timber using hand tools, measuring equipment and machinery to produce the pattern tooling. Harrop Casting Technologies prefer utilizing modern CNC machining methods to produce pattern tooling from high quality polyurethane tooling board materials. This provides an optimum combination of accuracy, consistency, durability, and cost.
Pattern tooling is generally a requirement for producing castings with moulding sand being specially prepared then compacted around the pattern and cured before the pattern is extracting leaving a perfect impression / cavity in the sand mould.
Advances in 3D Printing has enabled Harrop Casting Technologies to produce sand moulds without the need for expensive pattern tooling and enables supply of high integrity castings with a focus on getting your products to market in the best possible timeframe.
Complex cast shapes, low volume and prototype parts can ideally be produced with much shorter lead times than is possible with conventional tooling.
MELTING PROCESS
Aluminium Alloy primary ingot is supplied directly from reputable Australian suppliers. Each bar is individually bar-coded for traceability. All metal specifications data sheets exceed or fall well within Australian Standards AS-1874 2000.
Melting occurs in gas fired furnaces. These furnaces can provide molten metal 24 hours a day 7 days a week with temperatures and processes recorded.
Rotary degassing and flux injection of molten alloy guarantees premium cleanliness of every batch melted at Harrop Casting Technologies. Thus removing all dross, impurities and contaminants possible, giving us the confidence you receive nothing less than perfection.
HEAT TREATMENTS
Primarily CC601 or CC603 are used and heat treated to T6 and T7, for assigned applications. Harrop Castings Technologies are more than happy to discuss the best outcome for your application. Many hours of research in partnership with CSIRO have resulted in proven process controls. Each casting is individually date stamped for traceability.
AFTER CASTING FINISHING
All castings are carefully hand finished to remove flashing during the casting process. Each casting is then shot blasted with stainless steel shot to give the casting a uniform texture and finish.
CASTING GREEN IN A SAFE ENVIRONMENT
Harrop Casting Technologies supports a green future with the guidance of Environment Protection Authority South Australia in best practice recycling and energy usage. Harrop Casting Technologies prides itself by abiding by all Worksafe laws and regulations.