This technical information has been contributed by
Alphacasting Inc.

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Precision Investment Casting Specialist Produces Complex Parts for High-Tech Applications

Precision Investment Casting

The company saves costs for customers by processing numerous metals under one roof, eliminating the need to use multiple suppliers, and by using the same mold to cast parts from different alloys

Mark Shortt
Editorial Director
Design-2-Part Magazine

Investment casting, a process reportedly used to craft ornaments and jewelry in ancient India, Africa, and China, is today being used to manufacture precision parts for industries such as aerospace, defense, medical, and telecommunications. For Alphacasting Inc., a precision investment casting specialist that counts some of the world's best known aircraft manufacturers among its customers, evolving to meet the changing needs of the high-tech marketplace is an essential part of its mission. According to Alphacasting General Manager Frederik Centazzo, the company manufactures parts from 120 different alloys and has developed "a unique way to cast thin-walled castings in aluminum and titanium," a process refinement that is said to maintain a high level of structural integrity, or strength, in thin-walled parts.

Alphacasting (www.alphacasting.com) recently completed a major expansion of its production facility, adding 19,000 square feet of work space that includes a new mold room and additional heat treatment capabilities. The company now has 75,000 square feet of work space at its Montreal headquarters, where it employs 120 people.

Design-2-Part Magazine (D2P) spoke with Frederik Centazzo recently about Alphacasting's unique service offerings, which include various ways that customers can save costs on complex, precision castings. Here's what he had to say.
 

D2P: What sets you apart from other investment casting companies?

Frederik Centazzo (FC): The difference between us and other companies is that we cast 120 different alloys, including aluminum, bronze steel, stainless steel, titanium, and all kinds of exotic alloys, like Inconel. We use different methods of pouring castings, such as vacuum casting, air melting, and controlled solidification. Most investment casting companies specialize in one metal, such as steels, aluminum, or titanium, but we can process many metals under one roof. So it makes it easier for our customers because they can come to one supplier for investment castings. Sometimes, we can use the same mold to cast the part in different alloys. 
 

D2P: What types of applications is your investment casting process best suited for?

FC: We are very specialized in fields like aerospace, military armament, and medical. These are the main market sectors that we are in. Our process is ideally suited to these applications because of the complexity of the parts, as well as their mechanical properties, low-to-medium volumes, and high functionality. For example, when you have a very high-volume part in aluminum, it will probably be done with die casting.

Also, there are certain limitations of design, where you cannot do the core inside, or you cannot have undercuts. But with investment casting, we are injecting wax, so we can do a part with much more complex geometry. We make some aerospace parts with a rate of 10 parts per year, but we also make an armament part at a rate of 20,000 per year. So our parts range from low to medium volumes with this process; everything depends on the complexity of the part. We can make parts with very complex shapes and tight tolerances.
 

D2P: What other advantages does your investment casting process offer versus competing processes?

FC: We can use the same mold and cast different alloys with it. For instance, I have some customers who are using aluminum, steel, and stainless steel for the same parts, so I can use the same tooling. This is a cost saving for them because they only have to manage one foundry instead of three.

The outstanding thing about this process is that we can do thin walls with complex geometry. And the process saves a lot of time and money on machining because we can cast most features “net” (to a net shape) on the part. This reduces the number of features that need to be machined.
 

D2P: How does your process allow the manufacturing of thin-wall titanium parts with high structural integrity?

FC: Our pre-heated molds allow Alphacasting to cast thin sections. We are doing more and more of the thin-walled titanium parts; we can do a wall thickness of 0.0060 inch with titanium. We have some aluminum parts on which we are holding a wall thickness of 0.0023 inch.
 

D2P: What types of applications is the process not as well-suited for as competing processes?

FC: Sometimes, we will tell the customer that a part is not suitable for investment casting. When you have a very simple part, in terms of geometry, and you have very high volume in aluminum, die casting is a better process. If you have a very large aluminum casting, without any complexity, then sand casting is the best process. It's the same thing with steel and titanium parts.

But if the part is complex and you need good mechanical properties, investment casting is the best. We have some parts that went from permanent mold to investment casting because they had a lot of machining after the molding. We can do these parts and meet the same complexity and tolerances without any machining. Everything depends on the shape of the parts and the metal used.
 

D2P: It was reported earlier this year that a lot of manufacturers in Quebec, particularly those serving the aerospace industry, are anticipating an increase in business activity. How's the market for manufacturing in Quebec these days?

FC:  Our U.S. military market segment is soft at the moment, but we expect new programs to be released later this year. Montreal is the aerospace area for Canada; we have some big companies here, such as Bombardier, Pratt & Whitney, and Bell Helicopter. But we still have companies here who are going through tough times. We might eventually be doing parts for the new C-Series airliner made by Bombardier, but right now they're mainly focused on making prototype parts. Down the road, investment casting will be a good option for them.
 

D2P: What types of structural parts have you produced for the aerospace industry?

FC: We make parts that go on the wings and landing gear of aircraft, as well as parts for the cockpit and engine. We make a fuel probe part that holds the measurement system on the fuel tank. We also make the hand wheel for the aircraft; cockpit display components; fuel tanks for small aircraft; rudder pedals; seat brackets; and quite a few other aircraft parts.
 

D2P: What's the geographical range in which you do business?

FC: Most of our work is in the U.S. and Canada. We've started to do some work in Europe--France and England--and we have some customers in Israel and Australia. We're trying to be more diversified in looking for work in Europe and the United States, mainly on the West Coast.

I would say about 50% of our work comes from the United States. We buy all of our raw materials in the U.S.; we don't buy any materials from China or other third world countries, mainly because we have to use certified materials for our aerospace and military work. We can work on the American military programs because there is a Canadian clause in the ITAR regulations. As long as we adhere to the technical agreement and the specifications of the parts, we are just fine.
 

D2P: Can you talk about some of your high-tech applications?

FC: Examples include medical parts, such as implants and heart surgery tools; and high-tech military work, such as electronic telecommunication parts. As time goes on, we will be doing less commercial work due to competition from the Far East. Demanding aerospace, military, and complex parts will remain here due to geographic and technology constraints. They are more complex, they have NDT (non-destructive testing) requirements, and they have close tolerances and dimensions. We do all of the tests in-house, which is an added plus for our customers. All of our tooling and our heat treating for steel and aluminum is also handled in-house.

We are NADCAP, ISO, and AS (aerospace certification) approved. Quality control is very critical with the high-tech parts; we have to check every part and component. Most of these customers don't allow any deviation in terms of tolerances and dimensions, so they have to be perfect parts when we ship them out.

We also have engineers on staff: three metallurgical engineers, two mechanical engineers, and one process engineer. We do design work for our clients, and we use CAD for 3D design, toolmaking, and rapid prototyping.
 

D2P: What types of medical implant parts have you produced?

FC: The first implant parts we are doing are titanium knee implants. These parts have to be very clean and have a nice smooth finish. The material's chemistry is very important, and process controls are very tight. We have to do micrograph inspections to check the structure of the parts, and do NDT X-ray inspections. Even the cleaning of the parts is very important, so that no burrs are evident, even microscopic ones. The final parts have to be approved by the FDA, so process control is very critical for the implants.
 

D2P: Your website states, "By virtue of our service to several types of industries, we are in constant evolution and regularly demonstrate versatility."  Can you tell us more about this?

FC: When we discuss the job with our customers, we try to give them different alternatives. Compared to other foundries, we try to put as many features into the castings as possible, so that it saves on machining. Also, we can provide them with castings for many different alloys. So we always try to push the limits of the process. We're not the least expensive foundry, but our sales people explain that they're getting a very complex, precision part with a lot of features. We try to do whatever we can to save on machining time, and we can help a customer redesign a part that is not manufacturable enough.
 

D2P: Can you talk about some of the recent additions to your facility, and what these additions mean for your customers?

FC: To keep up with the global economy, we have to constantly be upgrading our equipment and R&D. We've spent more than $1.5 million on new equipment last year that we're installing right now--live X-ray inspection equipment, burn-out ovens, a vacuum heat treatment and gas quench oven for steel. We've built a brand new shell room and a new foundry for aluminum. Before, we were only able to make 18-inch parts, but now we can make 45-inch parts.

This will double our production capacity for aluminum, and, on the steel side, it will give us the ability to do heat treating in-house. We have plenty of capacity on the vacuum processes--vacuum arc melting (VAM) and vacuum induction melting (VIM)--for casting titanium and other exotic alloys. The new machines are very efficient.

With our "live" (real time) X-ray QA unit, you don't need to have film. You just put the part into the machine, and you can see the part features right on the screen. This is a big cost saving compared to using film. We use the X-ray machines for foundry control verification, so we know what's going on with the part after pouring.
 

D2P: How much of your business is devoted to rapid prototyping?

FC: We're pretty new to the rapid prototyping. Less than 1% of our work is prototyping, but more and more of our customers want prototypes to validate their designs. We have a selective laser sintering (SLS) rapid prototyping machine in-house for making patterns, and we also subcontract SLA plastic patterns. We don't make injection molded parts, but sometimes we make soft tooling--often made out of rubber or epoxy--for a mold that will last for about 25 injections.
 

D2P: How does rapid prototyping complement your core capability of investment casting?

FC: It's a good way to get in contact and to interact with an OEM's engineers. The main advantage is that since we are directly involved with our customer's engineers, it allows us to check the gating and other aspects of the manufacturing before we cast the part. In this way, we step up to the production process more quickly.
 

D2P: Another process you offer is Hot Isostatic Pressing (HIP). Why do you offer HIP, and how does it improve the casting process?

Frederik Centazzo: We sometimes use it for aluminum, but usually for titanium and Inconel parts that have very critical applications. This is mainly used to compress porosity out of the structure of the metal. We have to use it for titanium in order to improve part density and improve static and dynamic properties of castings. We're the only casting company in Canada that does the VIM, VAM, and HIP.
 

D2P: Do you foresee any work for the energy industry, in either the traditional or renewable energy sectors?

FC: We're starting to see some inquiries in this field, but it's just in the preliminary stages right now. We produce a first stage blade for ground-based turbine generator systems. These natural gas-fired turbines provide peak power to the grid, complementing the use of other wind, solar, and hydro sources.

David Gaines contributed reporting to this article.

This technical information has been contributed by
Alphacasting Inc.

Click here to find suppliers

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