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'Core Competency' Includes Lost Foam at Mercury Marine.

This marine engine manufacturer is marrying pressurized lost foam with diecasting as it pursues jobbing work and redirects its captive production to core competencies.

In the quest to streamline operations to increase efficiencies and reduce costs, OEM engine manufacturers must determine what their core competencies are. What systems and components should they manufacture in-house vs. outsourcing to ensure consistent quality and cost-effective end products?

In the automotive industry, the big three (Ford, GM and Daimler-Chrysler) have determined that certain engine cylinder block and head casting production is a core competency from the standpoint of quality, cost and just-in-time delivery and should remain an integral part of their in-house manufacturing. However, in the construction and agriculture industry, firms such as John Deere have begun to rely on outside suppliers for all or almost all of their cast components.

This is the same situation examined by Mercury Marine, a manufacturer of outboard and inboard marine engines in Fond du Lac, Wisconsin, and its Mercury Castings Div. The firm was utilizing 42 high-pressure diecasting systems in a high-production diecasting plant and a 15-year-old lost foam line to produce various marine engine components including engine cylinder blocks, cylinder heads, crankcases, and transmission and gear housings. But the capacity of these casting facilities had reached a maximum, and efficiencies were not at an optimum level.

"We were producing many different cast components, almost like a jobbing foundry," said Dave Dickirson, director of Mercury Castings. In fact, Mercury Marine was producing more than 95% of all diecast components and 100% of all lost foam components in-house. In addition, the firm only purchased "a couple hundred thousand dollars of die castings last year."

To take action, the firm performed a SWOT (strengths, weaknesses, opportunities, and threats) analysis of all manufacturing, which also included a review of other OEM engine builders. By taking a cue from GM, BMW and Harley-Davidson in particular, Mercury Marine realized that the core competencies in casting for successful engine manufacturers revolved around the 5 Cs--the cylinder block, cylinder head, crankcase, connecting rods and crankshaft. These components are vital to a manufacturer's success in ensuring engine quality with complex designs and just-in-time delivery to production lines. The rest, it concluded, could be sourced on the outside.

"These engine manufacturers determined that success is built around determining where your expertise is and allocating it to the components that most influence the quality of your end-product," said Leo Santini, vice president corporate manufacturing. "We believe this path is the best to follow and will allow us the best opportunity to increase efficiency and reduce costs."

Determining a Niche

Beyond the ability to streamline its own production, a focus on the 5 Cs presented another unique opportunity to Mercury Marine. In 1985, Mercury Castings built a R&D lost foam line capable of 20 flasks/hr to produce aluminum engine blocks and cylinder heads. The goal was to determine the feasibility of the lost foam process for full-scale production. Over 15 years of production, however, this line grew to account for 15% of overall casting production. In the process, the firm developed true proficiency in the design and manufacture of complex small engine components via this still-emerging casting process.

One example is a 60 hp 3-cylinder engine block (Fig. 1). Previously manufactured as eight separate die castings, Mercury Marine engineers converted them to a single 22-lb lost foam casting with a weight savings of 2 lb per block and a cost savings of $25/block. Lost foam allowed the engineers to consolidate the engine's cylinder head and exhaust and cooling systems into the block and eliminate the associated machining and fasteners required in down-the-line processing.

This type of design proficiency signaled an opportunity. In its SWOT analysis, Mercury Marine asked the question, "What other small engine manufacturers have the ability to design and manufacture similar complex cast components?" The answer: very few. In fact, Mercury Marine determined that the current demand for such components was far greater than the supply available. Plus, this demand was only going to increase with each passing year.

"OEMs are looking for lost foam casters with our skill in design and casting of complex small engine components," said Dickirson. "There was a niche that needed to be filled, and we had already developed the expertise to do it."

Mercury also was in the midst of developing a new V6 engine utilizing its newest alloy development, B391, a high corrosion-resistant aluminum alloy with increased wear resistance (due to a microstructure that has a uniform spatial distribution of primary silicon because of a narrow solidification range) that provides for shape control of the iron phases. The engine design also required a cylinder block and head integration that features hollow sections that couldn't be cored-out in diecasting or semi-permanent mold (the processes used for its other V6 blocks). Based on the success the foundry had with the 3-cylinder lost foam block, Mercury's engineers identified the V6 for lost foam.

These determinations in regard to core competency, a strong supply need, and its own new engine developments, led Mercury Marine to one decision: "We needed to refocus our casting efforts on the 5 Cs--primarily cylinder blocks and heads and crankcases--and increase our capacity for lost foam to accommodate current and future captive production as well as a push for non-captive work," said Dickirson.

Pressurized Lost Foam

The refocusing is beginning with lost foam, and, more specifically, with pressurized lost foam casting. This path is due, in part, to emulating GM and its aggressive pursuit of lost foam. An examination of the diecasting operations is under way at Mercury and the firm expects that it will resource components outside its niche over the next 3-5 years.

With the new V6 engine on the horizon and a desire to solicit non-captive business, a new lost foam facility capable of higher production volumes was required. The result is a just-completed 20,000-sq-ft lost foam casting plant (with 56-ft-high ceilings), which made its first pour in April and first production run earlier this month. The $10.7 million facility, which was engineered by both Mercury Castings and Vulcan Engineering Co., Helena, Alabama, has a single lost foam line operating at 24 flasks/hr, and is projected to produce up to 5 times more than the old lost foam line.

Overall this lost foam line is state-of-the-art technology, according to Dickirson, but it is centered around the first North American installation of the French firm Pechiney's Castyra] Process for pressurized lost foam casting. This process, which applies 10ATMs of pressure during casting solidification, provides Mercury Marine with three advantages for its components:

* reduced porosity to near undetectable levels;

* increased elongation properties;

* increased fatigue life.

In the past, the full potential use of this pressurized process had never been realized by other lost foam casters due to the copper content of the alloys being cast. Due to this, Mercury Marine only uses copper-free aluminum-silicon alloys (such as 356 and 391) due to their high corrosion resistance and unique feeding response to modest applied pressure.

During pressurized lost foam casting at Mercury Marine, the flask is lifted from the foam line by a gantry (after being filled with the foam cluster and molding media) and placed in one of six pressure vessels (Fig. 2). The robotic arm then pours, the lid on the pressure vessel is closed and 150 psi of pressure is exerted on the casting for 15 mm as it solidifies.

After 15mm, the flask isremoved from the vessel and placed back on the line for automatic extraction, quench and finishing. Both conventional and pressurized production can be run on the same line.

According to Dickirson, the "white side" (foam pattern production) will remain outsourced initially because "it is critical that we reduce the number of variables in the start-up of the new facility. The supplied foams are attached to sprues at the plant to form the clusters, which then are robotically cooled and transported through one of two drying ovens to the lost foam line where they are manually fed to a positioning device that lowers the cluster into the flask. A synthetic mullite is then rained over the cluster as vibration is occurring to fill the flask. According to Mercury Marine, this mullite allows the firm to produce more complex components than could be done with silica and olivine sand, while also achieving the casting dimensional precision of diecasting. In addition, this material can be reclaimed repeatedly without losing its original properties and low-expansion characteristics. The firm was the first lost foam foundry in North America to utilize the mullite for production when it adopted it for the original lost foam line in the '90s.

Once the flask is filled, it is either poured on the line or transferred to a pressure vessel for pouring. A robotic pouring arm then dips into one of two 40,000lb reverberatory furnaces positioned adjacent to the molding line. The two furnaces allow Mercury Marine to alternate between two different alloys for pouring. These holding furnaces are fed from one of four smelter-fed reverberatory furnaces (one 25,000 lb and three 40,000 lb) that serve both the diecasting and lost foam plants.

After casting solidification, the flasks are automatically rotated for casting extraction and a robotic arm removes the metal cluster for water quenching. Once quenched, the components are automatically fed to cleaning and finishing.

The lost foam line will cast a V6 engine cylinder block and both a 2 and 3 cylinder two-stroke engine block, all with integrated cylinder heads. Mercury Marine has an edge in the start-up of production on all these components as it has been able to produce them on its original line and weed out many of the production "bugs." Although there will be other production issues to sort out in the new facility, they are expected to be process-related, not foam-related.

While the direction of the foam facility is known, the future of the diecasting business is still under examination. Some components may be retooled for lost foam to increase component complexity as with the 60 hp 3-cylinder block in Fig. 1. However, not all components can be redesigned with these advantages.

Mercury Marine has 100,000-sq-ft of production space designated to diecasting for engine blocks, exhaust manifolds, transmission and gear cases, and various other engine-related components. The firm utilizes 42 high-pressure diecasting machines and two low-pressure semi-permanent mold systems. These machines are incorporated into cells in which one operator performs multiple tasks (such as a trim press operation and visual inspection) in conjunction with casting duties.

Currently, diecasting is the only area within Mercury Marine that produces components for outside customers. Overall, 15% of current casting production is shipped to customers such as Harley-Davidson and Polaris. This was begun three years ago when Mercury Marine was trying to improve its efficiency by filling capacity.

Building Outside Customers

"We have a skill in lost foam casting production that is in high demand today, and will remain in high demand tomorrow," said Dickirson. "Knowing this, our new facility was built with extra capacity to service outside customers."

Although Mercury Marine had begun to produce diecast components for outside customers in 1998, the refocusing to core competencies makes its approach to non-captive work a new venture.

"We now will need to target customers that fit into our overall casting manufacturing plan," said Dickirson.

Dickirson states that Mercury Marine will target jobs that:

* have complex geometry;

* have part volumes from 25,000-500,000/year;

* are used in the non-automotive, small-engine manufacturing industries;

* have sales volumes of $500,000/year per part number.

"We have found our niche in low to medium volume complex castings where competition is sparse," said Santini. "In this niche we will be a leader by providing support through the initial design to the manufacturing of the cast components."

Projections are that Mercury Marine will grow its commercial casting work from 15% to 50% in the next several years. This growth will be with the new lost foam facility and in both traditional diecasting and semi-solid casting.

On the lost foam side, 30% of capacity will be reserved for commercial jobs. Mercury has begun discussions and produced prototypes for jobbing work with two of its existing customers.

To support this new venture into jobbing work, Mercury Marine has developed various in-house resources to assist in component design. The firm has positioned itself with various methods of rapid prototyping (stereolithography, laminated object manufacturing and selective laser sintering) as well as finite element analysis and process modeling of casting solidification.

"We now are a full-service foundry that can assist our customers from the initial stages of design through manufacturing," said Dickirson. "We also now know what our focus is and where we want to be as a casting operation in five years. Our focus on core competencies only is going to make our marine engines better."

Mercury Marine-Mercury Castings Div. Fond du Lac, Wisconsin

Year Founded: 1969.

Metals Cast: 356, Xk360 (self-developed), 364, A380, 390, 391 (self-developed Mercosil) and 515 aluminum alloys.

Mold Capabilities: Lost foam, diecasting and low-pressure permanent mold.

Melt Capabilities: On-site smelting operation to produce all low-copper alloys; and reverberatory furnaces.

Size: 200,000+ sq ft.

Value-Added Services: Rapid prototyping, machining, heat treating, assembly, painting, and tooling design and manufacture.

Key Markets: Captive--inboard and outboard marine engine components; non-captive--non-automotive small engine components.

2000 Production: 40 million lb (85% diecasting, 15% lost foam).

Employees: 400+

Corporate Officials: Leo Santini, vice president of manufacturing; Dave Dickirson, director of Mercury Castings; Dave Grebe, plant manager; John Behrendt, lost foam area manager; Tim Newman, sales manager; and Ray Donahue, senior director advanced materials and foundry technology.

Other Foundry Facilities: Stillwater, Oklahoma (diecasting, 75,000 sq ft); and Capitol Engineering, Brookfield, Wisconsin (tool and die).
COPYRIGHT 2001 American Foundry Society, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2001, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Comment:'Core Competency' Includes Lost Foam at Mercury Marine.
Author:Spada, Alfred T.
Publication:Modern Casting
Geographic Code:1USA
Date:May 1, 2001
Words:2295
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