Technical Articles

How big is .005 Inch?  In everyday life it is very small.  In the world of cast products these are amazingly tight tolerances especially when you consider that Investment Castings are manufactured without the need of a draft allowance.

The DOD “Better Buying Power” objective as stated by Dr. Carter, is to procure the goods and services needed by the country’s Warfighters within the constraints of Congressional Budget and the overwhelming need to upgrade and replace equipment currently in the field. 

Many confuse the word “Affordability” with the word “Price”.  They are not the same and there are quite a large number of articles available that are devoted to defining Affordability.  The short rendition, however, is that Affordability equates to the total cost of ownership.

Over the years, we have had the pleasure of having participated in numerous Collaborative Engineering events, several of which were quite unforgettable.  One instance occurred about ten years ago and began with a rather panicked phone request from an owner of a machine shop.  As it stood he was seriously delinquent on a contract because multiple casting suppliers had proven unable to produce a particular casting to print.  They had suggested their customer that O’Fallon Casting might be able take one of the existing two molds and manufacture “good” castings from it. 

Minor oversights during the design phase of a casting can lead to unintended downstream costs.  Let us consider two case studies we have encountered recently as examples of how overlooking the requirements of specifications on your drawing can lead to extraneous manufacturing steps. 

As it is with other hard alloys such as inconel or even stainless steel, the secondary machining of MMC castings is a significant cost component of their manufacture.   The near-net-shape advantage and the greater freedom of design that is inherent with the Investment Casting process provides opportunities to greatly reduce or eliminate machining content of MMC castings. 

Aluminum alloy / Silicon Carbide MMC castings can be produced in 20%, 30% & 40% concentrations of Silicon Carbide by volume and heat treatable, commonly being furnished to a T77P heat treatment.

With its unique set of properties MMC alloys have been employed in diverse applications such as moving structures in high speed equipment for manufacturing, brake rotors for vehicles, heat sinks for electronics and as housings & mirrors for optics.

OFC invests heavily with its Customers to forward our mutual success.  O’Fallon Casting represents so much more value in a supply chain than simply “good parts on time, every time”.

Investment Casting-201 is a three day class taught at O’Fallon Casting on the basics of Investment Casting manufacture.  An IC-201 class provides an introduction to all of the investment casting manufacturing operations and includes hands-on experience with pattern injection, sprue assembly, gate grinding, straightening, radiography and penetrant inspection.  In addition IC-201 “students” receive 3-hours of classroom work, participate in a collaborative engineering workshop and are exposed to toolmaking, solidification modeling and defect analysis.