Aluminum Investment Casting

aluminum investment casting

In investment casting, aluminum is a popular metal choice. Since aluminum has a high strength-to-weight ratio, it is widely used in industries like medicine, electronics, and aerospace that require lightweight but long-lasting components. In addition to being resistant to corrosion, this metal exhibits strong thermal and electrical conductivity and can withstand high temperatures and extreme conditions. Aluminum investment casting yields components with a smooth finish.

Learn more about aluminum investment casting in this post.

Table of Contents

What is Aluminum Investment Casting ?

A refractory ceramic coating is applied to a wax pattern in the manufacturing process known as aluminum investment casting. Wax is melted off once the ceramic coating material has dried and set, leaving a hollow in the desired geometry. Aluminum in its molten state is poured into the space previously occupied by the wax pattern. Once the metal has cooled and solidified inside the ceramic mold, the ceramic can be removed. An array of industries can benefit from this method’s net or near-net precision metal component.

Investment casting, or the lost wax process, is a time-honored art and science. The ancient Egyptians and the Chinese contributed to investment casting development, which dates back more than 5,500 years. Industrially produced dental fixtures, machinery components, cams, gears, jewelry, ratchets, turbine blades, and other parts with intricate geometries are all examples of complicated items that can be created using this method.

The Types of Aluminum Used in Investment Casting

The metal parts are available in various aluminum alloy grades for customers to choose from. Let’s take a look at the most popular aluminum alloys for investment casting.

A356 Aluminum Alloys

Aluminum alloys with the designation “A356” contain mostly aluminum and silicon, with smaller amounts of the other elements listed. The strength, elongation, and ductility of this alloy are all exceptional. As a result of its versatility, A356 aluminum is widely employed in a wide variety of sectors to produce both straightforward and intricate components. Its low price is a result of its easy production and wide distribution.

A360 Aluminum Alloy

Many die casters avoid A360 because it is more difficult to cast than A380. Depending on your casting talents and demands, you may wish to use this alloy because of its increased strength at high temperatures, improved ductility, and corrosion resistance.

ALSi10Mg Alloys

Cast aluminum alloys with the ALSi10Mg grade designation are age-hardened metals (precipitation hardening). The additional impurities in the aluminum are driven out by the heat treatment process, boosting the material’s strength. This alloy offers low density, strong corrosion resistance, and mechanical strength.

A380 Aluminum Alloy

A380 aluminum alloy is widely used for die casting. The combination of A380’s low density, excellent strength at high temperatures, and corrosion resistance make it the ideal material for casting. A380 also has strong electrical and thermal conductivity and is great at maintaining dimensional stability even with complex designs and thin walls.

A383 Aluminum Alloy

Die casts made out of A383 aluminum alloy are another viable choice. This alloy is employed only when producing complex components that require finely tuned die-filling qualities. It lacks some of the characteristics of A380, but it has greater strength at high temperatures and a reduced likelihood of shattering when heated.

BS L99

Castings of BS L99 aluminum grades have been solution-treated and precipitation treated to ensure compliance with British Standards. The main elements found in it are aluminum, silicon, and magnesium. Two of its many desirable qualities are high resistance to corrosion and easy machining.

BS L169

Another aluminum grade that meets British Standards is BS L169, which has been artificially aged and solution treated to make the castings appear older. The fluidity of the metal makes it suitable for castings with very shallow depths. It was strong and easily machined.

C355 Aluminum Alloys

C355 alloys are cast-grade aluminum containing copper, silicon, iron, magnesium, manganese, zinc, and titanium, but in higher concentrations. It has a lower ductility than A366 but comparable strength. The corrosion resistance and weldability of this alloy are also noteworthy.

F357 Aluminum Alloys

Foundry-grade metals, F357 alloys are mostly composed of aluminum, silicon, and magnesium. The absence of beryllium in the alloy makes it a suitable replacement for A357 and other aluminum alloys containing this metal. This alloy benefits greatly from heat treatment and is exceptionally strong.

The Benefits of Aluminum Investment Casting

The manufacturing of metal components is highly flexible. In terms of output, quality, and precision, all of the options are good ones to pick. The investment casting technique has emerged as the method of choice for the manufacture of high-quality, precision components. Investment casting is the best method for producing modern parts since it is cheap, flexible in terms of design, and scalable to any quantity.

Investment casting has replaced all other methods of metal fabrication in the industrial and commercial sectors due to its many benefits.

Adaptability in Design

Particularly complicated and sophisticated pieces, which may have a wide variety of internal and exterior shapes, benefit greatly from design freedom. Castings made via investment need not be of a specific size, shape, or thickness. As a result of its versatility, it can change and adapt to any situation.

Reduced Margin for Error

The most notable benefit of investment casting is the ability to achieve closer tolerances. A designed item must be built to the exact standards to provide a seamless fit with other components. Casting tolerances (CT) of five or six are typical for investment-casting parts.

Superior Textures and Coatings

Superior finishes can be achieved using investment casting with minimal post-production work. The method is well-known for the variety of finishes it creates. The surface finishes produced by this method are superior to any other casting method. Investment casting is the only manufacturing process that can achieve the same level of precision and quality of finish.

Fewer Defects

As every production manager will attest, defects are the primary cause of both production delays and increased labor expenses. Manufacturing defects lead to scrap, additional machining time, and slower production speeds. Investment casting doesn’t include any of these drawbacks. In addition to producing faultless results, this method eliminates the need for post-production work.

A part’s surface is smooth and uniform once it’s been separated from the shell, and it’s ready to be packaged and dispatched.

Less Waste

Waste, or the leftover materials after production, is another key cost in every manufacturing operation. The quantity of waste created by investment casting is greatly reduced due to the minimal post-production finishing that is required. Reduced manufacturing costs, worker compensation, and turnaround times are just a few of the advantages of reduced waste.

The absence of waste also eliminates the requirement for specialist equipment like heavy-duty grinders, deburring equipment, and other cutting tools. Energy savings, productivity gains, and the company’s bottom line also play a part.

Increased Productivity

The quantity of components that can be manufactured using investment casting is infinite. Investment casting is a reliable and efficient method of mass-producing components, whether you need just a few or thousands. Investment casting can be used to produce and finish components weighing as little as 0.1 kg or as much as hundreds of kilograms.

Fine Details

Finding a casting method that can make small, intricate parts are challenging. Because of this quality, aluminum investment casting was chosen to help the aerospace industry, and early jet aircraft were cast this way. As we advance into the technological age, the importance of perfect components and precise dimensional tolerances will rise.

Every stage of the investment casting process is calibrated to achieve flawless detail, from the creation of the pattern to the firing of the ceramic shell to the removal of the finished casting.


Sustainability is one of the driving forces behind today’s successful businesses. A clear advantage in investment casting. Waste is not produced when patterns, wax, ceramic slurry, and stucco coatings are reused. This feature of the procedure is what has made it so widely adopted.

How Does Aluminum Investment Casting Work?

Before the 20th century, when improved methods for removing the wax from the casting were established, the modern industry paid little attention to the fact that investment casting had its origins in China.

Investment casting’s popularity skyrocketed during World War II because it allowed for producing highly accurate and defect-free components that would have been impossible to create with more conventional techniques. Immediately following the war, it replaced all other methods as the method of choice for complicated industrial applications.

For the detailed process, please refer to article < Investment Casting You Should Know>

Products Produced From Aluminum Investment Casting

Aluminum investment casting is applied to the following industry:


The first industry to use aluminum investment casting in producing parts with impressive finishes and tolerances is aerospace. A vast array of metals is required to produce investment casting and flight components that provide various essential metal selections. Investment casting produces quality components with minimum materials and less energy loss using any metal.

Aerospace parts need to survive the change in pressure, harsh weather, and other forms of operating wear. This necessitates they have excellent endurance. The investment casting method offers the requisite uniformity, precision, and tensile strength to meet and surpass the criteria. Its key value for aircraft is its accuracy, which allows interrelated parts to match up fast and effortlessly.


Locks need to be durable and resilient. Aluminum investment casting permits for the production of specialized locks as well as regular locks for household applications. The locks should match correctly, mandates their casting to be accurate even to the smallest detail.


Investment casting is essential for the firearms industry because it enables the creation and implementation of novel designs. When making firearms, precision and accuracy are essential. Investment casting components offer net forms that may be made from various metals.

Investment casting minimizes the quantity of metal that needs to be removed during the finishing process. With CNC machining, businesses can produce consistent, uniform parts at a competitive price.

Medical and Dental

Precision devices and components that meet the medical and dental fields’ stringent dimensions and tolerance standards are in high demand. Investment casting is used to make instruments, implants, equipment, wheelchairs, and stretchers for medical use.

Investment cast components may save lives. Thus their production is crucial. Each and every piece of hardware has to be top-notch.

Food and Dairy

All the food we consume is produced using an enormous variety of tools. Investment casting produces the bits and pieces that go into such massive machinery. Parts used in the food sector must be precise and long-lasting, so these materials are typically stainless steel or specialized alloys. Many kitchen appliances rely on investment-cast components, including meat slicers, poultry processors, ice makers, barbecues, and warmers.

Fluid Power

Fluid power is a method of transmitting energy through the use of fluids or gases. To do this, hydraulic and pneumatic machinery is used to transform the energy input. Ball valve parts, steam trap parts, needle valve parts, impellers, pump components, and compressors are all examples of the kind of parts that must be sourced. Like the food and dairy industries, the fluid power business relies heavily on stainless steel, aluminum, and other specialized metals.

Factors that Affect Dimensional Accuracy in Aluminum Investment Casting

Investment cast components’ precision and reliability can be affected by several variables. Casting is a complicated process that requires careful attention to several factors, including shell heating, part design, molding, pouring, and casting material. Variations in size might result from mistakes in the manufacturing process that affect the shrinking rate.

Shell Heating

When the shell is heated incorrectly, it can have a negative effect and cause just a slight expansion.

Casting Material

The material used in the casting process, like with any other, has a significant impact on the final product. Since shrinkage is proportional to the square of the carbon concentration, less carbon means less shrinkage.


There is some variation in shrinkage rate depending on the material used to construct the shell. Zircon sand and other minerals with a low expansion coefficient are perfect for this use.

Casting Structure

The wall thickness of a cast portion has a role in the casting’s overall framework. They can accelerate the pace of shrinkage if they are overly thick. In contrast, the opposite is true if the wall thickness is too shallow. A decrease in size may be caused by a blockage caused by an excessive free systolic rate.


The temperature at which the molten metal enters the gates is known as the pouring temperature. Defects, like coarse grains, will form within the structure if the temperature is too high. Keeping the molten metal at a low temperature makes it easier to work with. A temperature of 1650 C (3002 F) is suggested.

Shrinkage is the primary issue with insufficient pouring temperature. Shrinkage can be minimized by maintaining a steady temperature during the pouring process. As the temperature rises, the amount of energy needed to maintain it stays the same, but the resulting products are more reliable and exact.

Wax Injection Temperature

Of course, the injection temperature and pressure will impact the final casting product.

Aluminum Investment Casting Company

Aluminum investment casting is a metal working technique where in a ceramic shell is constructed over a wax pattern made from aluminum die, resulting in components with very uniform and smooth surfaces. The process eliminates the requirement for post-casting finishing while reducing material and energy waste.

If you have a project that require Aluminum Investment Casting, finding a reliable & trusted company is very important. Leisheng Machinery is a world leading investment casting manufacturer, which can supply Aluminum investment casting services, founded in 1991, located in Ningbo China. Working with many famous brands on the word. If you are interested, please feel free to contact us.

About Us

Leisheng Machinery is a professional manufacturer in China since 1991, founded by Li, which is a famous china enginner. At the very beginner and we only focus on CNC Machining. And in 2006, our capabilities extend to casting, including investment casting, aluminum die casting & sand casting. In 2008, we build our another fatory, and our capabilities expend to metal forging.

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