Customers, technology steer GM's casting operations.
Those of us who worked in the Melting Department at the then-General Motors' (GM) Chevrolet Grey iron Foundry in the middle and late 1970s joked regularly that we spilled more iron in a day than most foundries melted in a month. The not-so-subtle implication was that we were the "biggest" and could afford to screw up. We could always melt more.
It would be a safe bet that the management team heading up the company's casting operations today would find little or no humor in that '70s shop-floor attitude.
And while I never heard it firsthand from anyone in authority, those of us with frontline supervision responsibility would talk often about management's and engineering's lack of interest in technical improvements, which weren't the result of development work coming directly from our facility. I learned later that this was called the Not Invented Here Syndrome.
Back then, making more iron castings faster was our only guiding principle.
That was then, and now is now. Grev Iron Foundry in Saginaw, Michigan (recently renamed Saginaw Metal Casting Operations), is no longer a Chevrolet plant, but part of GM's restructured Powertrain Div. Number 3 foundry--where I spent most of my waking hours back then tending cupolas and doing my best to keep iron chemistries in check--is now an aluminum foundry. Many of the materials and processes being introduced at the plant today were not even ideas then.
Today, Mike Williams, manufacturing director of GM's Casting Operations, talks about people involvement, synchronous and lean manufacturing, customer expectations, systems and breaking down paradigms.
On information sharing, Paul Mikkola, technical director of Advanced Casting Development, said, "I would like to see more foundries get as active in AFS and other groups as the GM and Ford foundries are. Generally, foundries, including us, have gotten a lot better about sitting down and talking to each other about problems and new developments. I think most of us have come to realize that we can't afford to duplicate each other's efforts anymore."
Asked if what we're seeing is a shift in GM's corporate culture, they don't avoid the question, but it's pretty clear that the new team isn't too interested in talking about the past--even though it's my main point of reference. Rather, their focus turns squarely to where the operation is today and where they need to be in the future.
Changing Casting Operations
Historically, GM has operated what is believed to be the largest foundry organization in the world. Until the early 1980s, each of the company's marketing divisions--Chevrolet, Pontiac, Oldsmobile, Buick and Cadillac--operated their own foundry or foundries. At the same time, GM's Central Foundry Div. also existed to service the needs of the various marketing groups.
Separate engine facilities were also operated by each marketing division along with one operated by Detroit Diesel. Transmissions were supplied by Chevrolet, Buick and GM's Hydramatic facilities.
In 1985, the engine facilities were reorganized into business and product teams comprised of the CPC Group (Chevy, Pontiac and Canadian operations) and the BOC Group (Buick, Oldsmobile, Cadillac). Responsibility for transmissions was merged into the Hydra-matic Div., while casting responsibilities were combined under the Central Foundry Div. Much of GM's research and development activities were reorganized into the Advanced Engineering Group.
In 1990, all engine manufacturing was combined into a single Engine Div. The Powertrain Div. was formed in 1991, teaming the engine and transmission operations. By 1992, the Central Foundry Div. was folded into the Powertrain Div., and Advanced Engineering was added in 1992.
By 1993, the reorganization was complete, and what had been a patchwork of various manufacturing operations that, in many ways, had no connection with each other, were streamlined into a single operating division of GM called Powertrain.
On the casting side during this period, several foundries were closed, including facilities in Tonawanda, New York; Pontiac, Michigan; and Saginaw. Production at several of the other foundries was cut back dramatically while the corporation adopted a strategy of focusing on what it calls its "product portfolio" of strategic components.
"In the past," said Mikkola, "we tried to produce every casting GM needed. Our product portfolio was just too broad and required too many areas of expertise. Today, our component strategy is to specialize on a small number of critical components like engine blocks, cylinder heads, pistons and other castings. Our goal is to know these products inside out."
For nearly a decade, GM has taken a long, hard look at whether or not it should be in the casting business. "That"s a question, like any part of our product portfolio, that we examine continually," Williams said. "In 1987, we began an in-depth analysis to determine what was strategically important to General Motors.
"We came to the conclusion that there's a very real strategic importance for GM to stay in the casting business for certain products. I think all of the major automakers have reached the same conclusion. There is a vital strategic value to internally manufacturing some components."
If and when the announced closings of the company's Danville, Illinois, and St. Catharines, Ontario, foundries come to pass, GM will continue operating five major casting facilities: gray and malleable iron and aluminum plants in Saginaw; a lost foam ductile iron and aluminum foundry in Massena, New York; a gray and ductile iron facility in Defiance, Ohio; and an aluminum diecasting and permanent mold facility in Bedford, Indiana.
Despite the reductions in its metalcasting capacity, GM remains a force in the international foundry scene. "We still run some of the largest foundries in the world and produce more castings than any of the seven major automakers," said Mikkola.
At the same time, you're left with the distinct impression that "bigness" isn't quite as important at GM as it once was.
Advantages of Integration
"What the new organization allows us to do," Williams explained, "is to approach every project from a systems perspective. We believe that the engine and transmission make up the heart of every vehicle we produce and castings are the major components of these products. With the organization we have now, we can approach the development of a vehicle from a systems perspective and link the engine and transmission so that it's a package, one system.
"When the engine, transmission and casting organizations were separate, we could never get a true picture of the best way to approach things like machining. As an integrated organization, we now look at the casting side of the business and determine that even if a casting costs a little more, we might save later on machining costs. Or we can decide that it makes more sense to take the fins off the casting in the machine shop rather than taking them off in the foundry's cleaning room.
"For the first time," Williams continued, "we can sit down as an organization and decide what's the best thing to do for the customer--to take cost out and improve quality."
When Williams refers to customers, he makes the point of saying that while the car buyer is the ultimate customer, the Powertrain organization has come to recognize that keeping its internal customers is just as important.
"This has been the real benefit of the new organization," he said. "Now, the engine, transmission and casting operations sit down as teams. We have set times when we regularly sit down with our internal customers. One of the major things that we in castings have learned is that, in many cases, we have to walk away from traditional foundry wisdom and take a more structured approach to solving problems."
Williams points to the new Northstar engine and transmission package now being offered in some GM cars as a prime example of what the new organization has been able to accomplish.
"We believe this powertrain is something that has never been put in the marketplace before," he said. "The way that it is being received by the public tells us that we're definitely on the right track."
People and Technology
If meeting customer expectations is the driving force for GM's Casting Operations, implementing advanced technologies is one of the ways the foundry group is using to get there. "We're not using technology alone to meet customer expectations," Williams said, "but it is a big part of it."
Among the process and material developments already introduced into their foundry operations or currently being scrutinized are cast metal matrix composites, solidification modeling, squeeze casting, rapid prototyping and sand reclamation. One of the most interesting, though, is the introduction of an aluminum line at the old Grey Iron Foundry.
When the announcement was made that the foundry would begin producing aluminum cylinder heads, the decision was second-guessed by more than a few industry observers. But sifting through the reasons why the decision was made provides an in-depth look at how the culture of GM has changed during the past decade.
The most important driver for adding aluminum casting capacity is the growing need to reduce overall weight of the cars GM produces. Design of the cylinder head enabled it to be made in green sand.
As explained by staff engineer Ron Cafferty: "We already had the green sand and cylinder head expertise in Saginaw. While most of our molten aluminum experience is in Bedford and Massena, we felt it would be an easier transition introducing aluminum to an existing green sand facility than it would be to introduce green sand to a diecasting or lost foam operation."
Also, in the past, the immediate reaction at GM to the need to bring on an aluminum green sand operation may have been to build a new facility. But as was pointed out earlier, that was then, but today it's different at GM.
The Number 3 foundry at the sprawling gray iron complex had been idle for some time. There was plenty of room. Coremaking facilities and the sand system were already in place. These, along with an existing cope and drag molding line, were reengineered to meet the needs of the new aluminum operation. When the first line is in full production and running to satisfaction, there is easily enough room for a second.
"The biggest drawback to bringing aluminum in here," said Mikkola, "was that our people were not used to handling molten aluminum. We've made a very special effort to teach them how to work with aluminum. We brought some of our people in from our aluminum plants as well as outside trainers. With the help of our Advanced Development Lab, which is located directly behind the Number 3 foundry, we've made excellent progress in integrating aluminum into our operation here."
The decision to bring aluminum to Saginaw was buoyed by previous successes the casting group had in introducing ductile iron into their gray iron operations in Danville, as well as at their aluminum lost foam facility in Massena.
"We were told by several people that we shouldn't consider doing these things," Williams said. "We we're told that it was crazy and 'you are guys are thinking wrong.'
"Certainly, it's more difficult than having only one material in the facility. But we had the technologists and expertise here. We also had a good facility in Grey Iron that had been maintained well over the years along with a good workforce. We discovered we have very creative people here who thrive on challenges like this.
"We know we're not where we need to be yet but we've made great progress. We're confident we can make it work."
Thriving on Change
If there was one thing that was most evident throughout my discussions with the GM team, it is the genuine excitement from everyone I spoke with. "There is so much going on and so much energy around here, it's truly an exciting place to be," Williams said. "We're continually challenged with either the things that are going on or in the planning process.
"We've got an outstanding work force here and they are genuinely enthused about the change they see going on around them. Everything we've talked about is either in production or will be within the next five years."
But there are plenty of changes and challenges ahead. Talking about future challenges, Mikkola explained that: "Our focus is and will continue to be trying to create lighter-weight materials at an affordable cost. This is a real challenge. Most of the things that are easily done were done in the last decade. Now we're facing some real technical barriers that will have to be overcome in order for us to move on to the next level of improvement.
"We're currently looking at titanium alloys and cast metal matrix composites with robust designs that will allow us to produce hundreds of them in an hour rather than in the small lots that aerospace applications require. This is a tremendous, tremendous challenge. There is still a big gap between where the world is today and where we need to be."
While the new GM team may find very little to laugh about when it comes to our 1970s shop-floor comments, they can still find some meaningful humor in their current situation.
As Williams explained it: "There's an old joke out there that the only person looking for change is the bus driver. But we are the bus drivers, always looking for change. We're thriving on change."
"Remember how we used to study mold filling?" asked Ron Cafferty, Casting Operations staff engineer. "We used to pour tomato juice in clearplastic molds. Now we do it in electrons, with many more iterations on the computer screen."
GM's Casting Operations have been using advanced solidification modeling for several years, according to David Goettsch, senior project engineer. "Working with the GM engine and transmission plants, we've been able to quickly change part designs to make them more castable, anticipate possible casting defects and perform stress analysis tests before the part gets anywhere near the shop floor."
According to Mikkola, "Solidification software is to us what spell-check systems are to a typist. It checks the casting for us."
The software also has the capability to allow engineers to examine mold fill prior to production. "This is particularly helpful," reported Cafferty. "We work with all of the casting plants, and modeling helps us switch very quickly between various ferrous and nonferrous alloys as well as casting processes, from sand casting to diecasting.
"It's also helping us look at possibilities of working with new intermetallic materials like titanium-aluminide."
This series of photos demonstrates one of the ways GM engineers are taking advantageof math-based modeling. Using a cross section of a V-8 cylinder block, the photo sequence illustrates how individual sections within a casting can be analyzed. The views demonstrate how increments of time can be isolated to study mold filling characteristics and casting solidification.
Aluminum Casting at Saginaw Metal Casting Operations
The aluminum molding line recently installed in Grey Iron's former Number 3 iron foundry is a horizontally parted green sand system capable of producing up to 15,000 cylinder heads a day. According to Dave Hergenreder, who's heading up aluminum production at the facility, other features of the new line include a patented stopper rod pouring system that will allow for continuous mold filling of up 50,000 lb per hour.
The molten metal transfer system was designed to eliminate all exposure to air. The plant will also feature individual CNC machining centers, continuous heat treating (solution quench and aging) as well as automatic leak testing.
Rapid Prototyping at Advanced Development Lab
GM's Advanced Development Lab is playing a critical role in developing and implementing new technologies for Casting Operations. Much of the work currently under way revolves around rapid prototyping technologies.
"Our mission here," Dick Morrow explained, "is to take rapid prototyping to the next step--to take it from math to metal. We produce models of the part and then convert the models into either castings or tooling. There's no throwing the technology over the wall. We don't say 'Here it is, manufacturing--catch it.'"
The lab features production facilities for making castings by green sand or investment casting. According to Morrow, who heads up the ADL, volume, cost and degree of complexity will determine how a part will be produced. "Our job is to help our customer determine the best way to proceed in production of cast components."
As this series of photos illustrates, the "math-to-metal" approach can be fully implemented within the confines of the ADL. First, a rapid-prototyping team member develops a part parameter at an engineering work station. Another member then processes a precise, scaled version of the full size part. This is followed by attaching the gating system to the model. The expendable model is then converted to a casting using engineering materials. Ultimately, a single or hundreds of parts are produced in the ADL's foundry.
Squeeze Casting at GM's Advanced Material Development Center
The major thrust at GM's Advanced Material Development Center in Saginaw ranges from squeeze casting to the development of cast metal matrix composites. As shown here, the center uses much of the most advanced equipment and instrumentation. Among these are a 250-ton and 700-ton squeeze casting machine.
The 200-ton press (shown at left) is used for producing test specimens that are used for tensile, fatigue and other types of mechanical testing. The coordinate measuring machine is used for measuring tooling and castings. In order to evaluate internal casting quality, the AMDC utilizes an industrial computed tomography system.
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|Title Annotation:||includes related articles; General Motors Corp.|
|Author:||Kanicki, David P.|
|Date:||Dec 1, 1994|
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