Investment Casting Today

Stainless Steel Investment Casting

2009-07-16T09:00:00.000-07:00

Stainless steel investment casting serves a wide range of commercial applications. Stainless steel is a ferrous alloy with a chromium content of 10.5% or more. Stainless steel is utilized for a variety of commercial applications because of its high strength...Continue

Shrinkage Allowance for Metal Casting

2009-07-14T08:58:00.000-07:00

A shrinkage allowance for metal casting is something that must be figured into a design from the very beginning. As the molten metal cools and solidifies it will begin to contract. This means that although the molten metal completely filled up a mold, by the time the casting was cold, the casting is smaller than the mold.

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Prototype Aluminum Casting

2009-07-10T05:00:00.000-07:00

Prototype aluminum casting is the ideal way of testing the performance of parts for intended applications. One can see the original design complexities before going into full-scale production of casting parts. It saves time and money for manufacturers who produce parts for various applications.

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Precision Investment Casting

2009-07-08T05:00:00.000-07:00

Precision investment casting is regarded as the premier casting technique that can produce net or near net shape casting parts with close tolerance and excellent surface finish with any alloy. Precision investment casting has a wide range of applications that require thin wall capabilities and smooth surface finish.

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Outboard Motor Parts

2009-07-06T05:00:00.000-07:00

Outboard motor parts are almost entirely created by some type of casting process. One of the reasons is that metal casting allows the use of alloys which have the desired properties for strength, durability and corrosion resistance. This is why you can still find old outboard motors being used today, along with being maintained well, their engine parts were cast to ensure longevity.

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A Boat Propeller

2009-06-05T05:00:00.000-07:00

A boat propeller can be cast from a number of metals and alloys. There are some boat propellers that are constructed from cast iron that consists of a mixture carbon, silicon, manganese, sulfur, phosphorus, magnesium, nickel, copper, titanium and a number of other elements. Such propellers are frequently used on outboard motors and can be driven at speeds up to 9,000 revolutions per minute.

Bronze, aluminum and stainless steel can also be cast for a boat propeller. Such propellers are used by ships, pleasure boats, cargo ships, ocean liners, tugs and trawlers for high speed and high efficiency. Casting foundries that specialize in boat propellers can cast up to a maximum diameter of almost 16.5 feet. Continue...

Aluminum Sand Casting

2009-06-03T05:00:00.000-07:00

Aluminum sand casting is the oldest and the most common metal casting technique. It is also the easiest casting technique to learn. The casting mold is made with sand. The pattern or structure is covered with sand, mixed with some fixative agents like wet clay. Then the design is removed, and the sand cover retains a cavity in the shape of the design, pattern or structure. Internal cavities or grooves are made with the sand and molten metal is poured into the cavity. The casting is recovered after breaking the sand mold. Continue...

Aluminum Pressure Die Casting

2009-06-01T05:00:00.000-07:00

Aluminum pressure die casting is the fastest method for mass production of precision parts. This die casting technique has a history of more than 150 years and the mass production of die casting components began around the 1900s. Aluminum pressure die casting is used to produce light weight, thin wall components of complex shapes, which demand stability at high temperatures and good corrosion resistance.

The die casting process involves the injection of molten metal into the die (mold) at high pressure. A high quality steel die is used for this process and the pressure varies from 5ksi to 10ksi (35Mpa to 69Mpa). The (cold chamber) temperature is set at 300° F to 500°F (150° to 260°C), well below the solidification temperature, to enable quick solidification....Continue

Investment Casting from the Pyramids to the Present

2009-04-17T05:22:00.000-07:00

Investment Casting From the Pyramids to the Present, also referred to as lost-wax casting, has been in use for over 5,000 years, from the pyramids right up to the present. The basic idea behind the process is to create a model out of wax of the object to be cast or created. In the present, other materials that have a low melt temperature may be used in place of the common wax that’s been used for millennia.

As an example, an artisan might sculpt a little statue of a cow out of wax, taking care to detail around the eyes, hooves and horns. The wax model is then covered by the material that will create a mold, as described below.

Investment Casting from the Pyramids to the Present - 1: Once the model is created it is then covered with plaster or sand to create a mold of the model. After the mold has set, it is placed in a kiln or oven and heated to a high enough temperature to melt the wax, which flows out of the mold and is “lost”, thus the reason for the term “lost wax casting.” This leaves a hollow in the exact shape of the original wax model; in this example, the wax cow. Continue...

Aluminum Bronze Casting

2009-04-15T04:50:00.000-07:00

Copper aluminum alloys are commonly called aluminum bronzes. They contain 89-95% copper, small quantities of aluminum and in some cases there will be iron, nickel, manganese or silicon. Aluminum bronze casting is used for applications demanding high strengths and corrosion resistance. Aluminum bronzes form two distinct groups of copper aluminum alloys, AB1 and AB2, with iron, nickel and manganese as the component metals. Brass is another group of copper alloys.

Probably bronze casting was the first form of metal casting. That deduction is suggested by the discovery of bronze statues and sculptures from various parts of the world. Today we use aluminum bronze casting for a variety of applications, because of its retaining ductility and strength at elevated temperatures and adverse conditions. The corrosion resistance depends on the casting process and the heat treatment it got. Continue...

Aluminum Investment Castings

2009-04-13T04:36:00.000-07:00

When considering aluminum investment castings you need to be aware of the pros and cons, the advantages and possible drawbacks. You must have heard if you are part of any relevant industry, about the benefits of using aluminum castings for today’s industrial needs. There are many uses for aluminum parts in the industry of 21st century – some demanding pure aluminum, while others involve the use of other metals to mix and form different types of alloys.

The Advantages of Aluminum Investment Castings

There are many, many benefits that would benefit any industry which adapts aluminum investment castings for their needs of metal parts duplication or manufacture. The main benefits would be:

Corrosion resistance – aluminum investment castings uses aluminum because it does not corrode like its counterparts such as iron, copper and the like. Though it is not as conducive the copper, aluminum makes up on that by its anti-corrosive properties. Continue...

Aluminum Alloy Properties

2009-04-10T05:23:00.000-07:00

Aluminum alloy properties, the mechanical and physical characteristics of the alloy, experience change when exposed to elevated (max. 400°C) and extremely low (cryogenic, -195°C) temperatures. These temperature-related changes are not as obvious as they are with steel and other metals. Additionally, the types of changes evidenced by aluminum alloys due to extreme temperatures are greatly influenced by the actual temper and chemical composition of the metal.

The best room-temperature tensile properties are found in aluminum alloy investment casting ingots of the 7xxx-series alloys. Unfortunately, exposure to high temperatures causes that strength to rapidly weaken due to the fin precipitates coarsening. And while series 2xxx aluminum alloys do well at elevated temperatures, they’re not usually employed in such applications. Continue...

Aluminum Copper Investment Castings

2009-04-08T05:34:00.000-07:00

Aluminum copper investment castings use the nonferrous metals of aluminum and copper. The term nonferrous means that the particular metal under discussion does not contain iron. Both aluminum and copper investment castings can be created with alloys rather than the pure metals.

Aluminum Investment Castings

Aluminum is the most commonly used nonferrous metal for investment casting purposes. Aluminum is a lightweight metal. Products and parts made with aluminum are appropriate for use in a wide variety of applications, including aviation, electronics, pump and valve housings, and military equipment.

Aluminum Copper Investment Castings as Alloys

Aluminum copper investment castings are created using the base metals of either aluminum or copper. Both aluminum and copper can be cast in their pure forms, although it is more common for them to be used as the base material for a number of different alloys. Continue...

Aluminum Alloy Castings

2009-04-06T05:15:00.000-07:00

The market for aluminum alloy castings is steadily growing with increasing demands from the fields of aeronautics, automotive and military applications. Aluminum alloys, especially aluminum castings, are considered as important structural materials that find applications in mechanical engineering. Properties such as being lightweight, machine-ability and a potentially unlimited supply of raw materials make aluminum the preferred choice for structural engineering parts. Aluminum can acquire the desired property of corrosion resistance or increased strength by adding the proper type of materials like magnesium, zinc or copper. The principle behind aluminum alloy castings is that the single continuous structure gives more stability and reliability than a structure welded together from different units.

Aluminum alloy castings are ideal for a variety of uses such as aerospace, electronics, and in valves and motors. Aluminum alloy castings include high precision parts that have a wall thickness of less than a millimetre to a thickness in the range of 800 to 1000 millimeters. Continue...

Alloy Investment Castings

2009-04-03T05:02:00.000-07:00

There are hundreds of different types of alloy investment castings. Alloys are created when a metal is mixed with one or more additional elements. Many different products are created with alloys rather than pure metals, for a variety of reasons. Typically, when a finished product needs a property not present in a pure metal, the metal will be combined with other substances that will result in an alloy that does provide the desired properties.

When selecting an investment casting manufacturer, it is important to be certain that you are selecting a foundry that has the ability to work with the type of metals or alloys that are best suited for your products. There are hundreds of different types of alloy investment castings. Two of the most commonly used alloys for investment casting are aluminum alloy and nickel based metallic substances. Continue...

Aluminum Alloy Casting

2009-04-01T05:19:00.000-07:00

Aluminum alloy casting is the process of creating solid shapes from an aluminum alloy. Metal alloys have been around for a long time, but the precision casting methods used are frequently refined. Within a span of about two thousand years from around 5000 BC, mankind first learned how to extract and manipulate metals from heating copper ore - a natural combination of minerals. Today, this learning process has evolved into many alloys including one of the most useful metal alloys produced used in aluminum alloy casting.

Aluminum alloy casting uses a mixture of two or more ferrous and non-ferrous elements fused or dissolved into one metal alloy under extreme heat. In the case of aluminum alloy casting, these metallic elements are aluminum. Continue...

Advantages Investment Casting

2009-03-30T04:16:00.000-07:00

The major advantages of investment casting are extreme versatility, cost effectiveness and the precise dimension control it offers. It saves time and labor and ensures error-free, accurate dimensional parts, giving designers and engineers more flexibility.

The versatility is the major advantage of investment casting. It supports the production of a wide range of products, for a variety of industries. The fabrication of some designs can be difficult or impossible with other metal casting methods. Investment casting allows the production of thin-wall, finely detailed parts, with extreme precision control. It also allows the production of quality parts that are both ultra light and strong, with extremely accurate details. This technique avoids the necessity of welding and joining together different parts.

Investment casting can be used with a wide variety of metals and alloys. This gives designers and engineers the freedom to concentrate on functional aspect of the casting rather than on its production. This is also a major advantage of investment casting. Continue...

Steel Investment Castings

2009-03-12T14:08:00.000-07:00

The steel investment castings process is well suited for a wide variety of applications from manufacturing small parts and tools to supplying the needs of the nuclear energy, defense and aerospace industries.

There is practically no limit to the complexity of product designs that can be handled by steel investment castings.

Steel is widely accepted as an excellent choice for products and parts that need to withstand a great deal of wear and stress or that need to support heavy loads. Steel is stronger than any other cast metal which makes it very valuable in some industries. Continue...

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Rapid Prototyping

2007-08-10T07:31:00.000-07:00

The third type of rapid prototyping used at Shelmet Precision Casting, Inc. is stereolithography. Stereolithography is a technology commonly used to produce parts containing a good finish and a high degree of accuracy.

Stereolithography uses a liquid resin and laser to build a prototype layer by layer. By scanning the CAD design, cross sections of the design are built of a liquid photopolymer resin layer by layer, resulting in an extremely accurate prototype.

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Rapid Prototyping - Part 2

2007-08-08T05:19:00.000-07:00

The second type of rapid prototyping employed at Shelmet Precision Casting, Inc is molds made with epoxy or silicon.

Made by using pourable epoxies or silicon rubbers, these molds are designed for tooling and offer a high degree of accuracy.

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Rapid Prototyping - Machining Wax

2007-08-06T04:18:00.000-07:00

There are three different methods of rapid prototyping used at Shelmet Precision Casting, Inc. These methods allow small quantity productions to be completed featuring actual cast parts, which can be shipped in a week or two.

The first method of rapid prototyping uses a very hard machining wax. This wax is specifically designed for proofing and CNC programs, as well as for building models, prototypes and patterns. Machining wax is easier to machine than plastic or metals, yet maintains the highest quality of finish. Dimensional accuracy and surface details are also maintained with the use of machining wax in rapid prototyping.

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Non Destructive Testing, Part 3

2007-07-28T19:32:00.002-07:00

Fluorescent Penetrant Testing

The most commonly-used of non-destructive testing methods is the liquid penetrant testing. A dye solution that is either visible or fluorescent is used to coat the casting part being tested. Any excess is blotted from the part before a developing agent is applied.

The developer pulls out any penetrant that has seeped into the part through imperfections that reach the surface of the part. An ultraviolet light causes the seepage to glow, revealing the areas of imperfection.

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Non Destructive Testing, Part 2

2007-07-28T19:32:00.001-07:00

Magnetic Particle Inspection

To find flaws on the surface or just below the surface, magnetic particle inspection is used. This type of inspection can only be used on iron-based, ferromagnetic metals, such as iron, steel, cobalt and nickel. Ferromagnetic alloys used in the casting must contain enough of the magnetizeable material for this type of inspection to be effective.

Flux, or magnetic lines of force, gets distorted when it attempts to pass thru a flaw. Thus this “flux leakage” follows the application of infinitesimal particles of iron to the part of the casting that is being examined. There might be some differences in the application of the magnetic field, but the principle of magnetic particle inspection is the same for all applications.

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Non-Destructive Testing, Part 1

2007-07-28T19:32:00.000-07:00

You can have your casting project put thru a number of non-destructive tests and analyses. These include a certified chemical and physical analysis, including the following types of inspection and non-destructive testing options:

Radiography X-Ray Testing
Penetrating X-rays or gamma radiation is used to inspect castings for imperfections. This radiography testing uses an X-ray machine or radioactive isotope as the radiation source. Like a normal X-ray, the radiation passes through the casting and creates an image on the film.

When the X-ray is developed, it creates a shadowgraph that reveals the internal accuracy and compliance with the original design. Inaccuracies and problems will be revealed as more dense portions on the film. Unsoundness will show up much like a broken bone will show up on an X-ray film.

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Freedom of Design

2007-07-27T03:53:00.000-07:00

These biopsy cubes contain several designed challenges: beveled edges, chambers that are recessed and corner with segregated areas. There was also a circular pattern on one side. The challenge was made even more difficult by the necessity of using one of the most unforgiving metals, 410 stainless steel.

Shelmet’s investment casting process provided absolute design freedom to the design engineers. If you have a design challenge, then you need to contact Shelmet. We love those kinds of challenges.

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Shelmet’s Expertise Saved the Day

2007-07-25T06:47:00.000-07:00

Before Shelmet, this part required a multiple handling process and machining. While the part used 356 aluminum and looked simple, it was actually quite complicated due to the square interior. The extensive machining required to produce the end result was extremely costly and time consuming.

Shelmet changed all that by using investment casting. As a result of our expertise in aluminum the casting was precisely what the customer specifications required. This was accomplished at a savings of time and money due to eliminating the necessity of conventional machining.

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Investment Casting Design Assistance

2007-07-23T20:40:00.000-07:00

Shelmet provided investment casting design assistance. The part's purpose was to hold the sole of a shoe during the shoe manufacturing process.

Shelmet Precision Casting, Inc. assisted in the design process, identifying the challenge. We were also able to recommend the proper close tolerances and alloy for the part.

Before investment casting the part, Shelmet created a prototype and test the part, to ensure that the design was correct. The process saved the customer both time and money, creating a part that was the most competitively-priced in the market.

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