What Is Investment Casting? KHD Investment Casting Production, Materials, and Applications

What Is Investment Casting? KHD Investment Casting Production, Materials and Applications

Investment casting is an advanced metal forming method that enables the production of metal parts with complex geometries, high dimensional accuracy, excellent surface quality, and repeatable production performance. Also known internationally asinvestment casting orlost wax casting, this manufacturing method is used across many industries, from automotive and machinery to defense and medical applications.

Based in Konya, Türkiye, KHD Hassas Döküm is aninvestment casting manufacturer producing specialized metal components for the needs of various industries. The company's manufacturing infrastructure enables the processing of different steel and metal alloys, the serial production of small and medium-sized complex components, and metallurgical controls throughout the production process.

Especially for parts that are difficult to manufacture using conventional machining methods, require numerous machining operations, or have complex geometries,investment casting technology offers significant advantages.

What Is Investment Casting?

Investment casting is a manufacturing method based on preparing a wax model of the part to be produced, coating the model with ceramic material, removing the wax from the mold, and pouring molten metal into the resulting ceramic cavity.

For this reason, the process is referred to in Turkish ashassas döküm orseramik döküm, while internationally it is known as investment casting or lost wax casting.

One of the most important features of investment casting is its ability to produce detailed geometries as a single piece that may be difficult to achieve with conventional casting methods. Thin sections, channels, recesses, protrusions, and various surface geometries can be transferred into production through proper mold design.

How Is Investment Casting Performed?

Investment casting production involves much more than simply pouring molten metal into a mold. The final quality of the component depends on a series of interconnected manufacturing stages.

Part Design and Technical Evaluation

The production process begins with the evaluation of the technical drawing, sample, or three-dimensional model provided by the customer. A manufacturability analysis is performed by considering the part geometry, wall thicknesses, tolerances, operating conditions, and material to be used.

This stage is particularly important for serial production projects. Evaluating the casting orientation, gating system, shrinkage allowances, and required finishing operations before the mold stage contributes to production efficiency.

Investment Casting Mold Preparation

Once the technical evaluation is completed, a suitable mold is prepared for the product. In investment casting, the geometry of the final component depends to a large extent on the quality of the mold and wax pattern.

In addition to being a supplier, KHD adopts a manufacturing approach that provides customers with support during product development and design stages.

Wax Pattern Production

Special wax is injected into the mold to create a wax pattern representing the metal component to be produced. This pattern reproduces the geometry of the final product with high precision.

When the same component is to be produced in series, multiple wax patterns can be prepared. This method provides significant advantages in the serial production of geometrically consistent and repeatable components.

Wax Pattern Assembly

The prepared wax patterns are assembled onto a gating system that enables the molten metal to flow into the individual components in a controlled manner during casting.

Because the resulting structure resembles a tree, it is commonly referred to as acasting tree orwax tree.

Ceramic Shell Formation

The wax trees are repeatedly dipped into special ceramic slurries and coated with controlled layers of ceramic material. This process is repeated until the required thickness and strength are achieved.

The quality of the ceramic shell plays an important role, particularly in achieving the desiredinvestment casting surface quality and accurately reproducing geometric details.

Wax Removal

Once the ceramic shell has reached sufficient strength, the wax inside it is removed under controlled temperature conditions. This produces a hollow ceramic mold containing the cavity corresponding to the geometry of the metal component to be produced.

The termlost wax casting originates from this stage of the manufacturing process.

Metal Melting and Casting

The metal or steel alloy specified for the project is melted to the appropriate temperature in induction furnaces. After the chemical composition of the molten metal is verified, it is poured into the previously prepared ceramic molds.

KHD has induction furnaces with capacities of 100 kg and 750 kg to meet different production requirements. This infrastructure enables production according to different component sizes and serial production volumes.

Cooling and Ceramic Shell Removal

After casting, the metal is allowed to cool and solidify under controlled conditions. The ceramic shell is then broken away to expose the casting tree.

The cast components are separated from the gating system and undergo the necessary cleaning processes.

Post-Casting Operations

Not everyinvestment cast component can be used directly in its as-cast condition. Depending on the technical requirements of the product, heat treatment, grinding, polishing, machining, surface treatments, or coating processes may be performed.

Through these processes, the component can be brought into compliance with the mechanical properties, dimensions, and surface characteristics required by the customer.

Which Materials Does KHD Use for Investment Casting?

One of the key factors determining the production capabilities of an investment casting company is the variety of alloys it can process. Components used in different industries require different properties, such as corrosion resistance, mechanical strength, hardness, wear resistance, and temperature resistance.

KHD's manufacturing capabilities include a wide range of materials, from carbon steels and stainless steels to tool steels, copper alloys, and nickel-based alloys.

• Carbon steels and alloy steels
• Heat-treatable steels
• Case-hardening steels
• Nitriding steels
• Tool steels
• High-speed steels
• 300-series stainless steels
• 400-series stainless steels
• Heat-resistant stainless steels
• Precipitation-hardening stainless steels
• Copper alloys
• Special nickel-based alloys

This wide range of materials enables the production ofsteel investment castings andstainless steel investment castings for different operating conditions.

Stainless Steel Investment Casting

Stainless steel investment casting is preferred in many industrial applications where corrosion resistance and surface quality are important.

KHD's alloy options include 300-series stainless steels such as 303, 304, 304L, 310, 316, and 316L, as well as 400-series stainless steels such as 410, 420, and 430.

Stainless steel investment castings can be used particularly in food-processing machinery, valve and pump systems, various machine components, and industrial applications exposed to corrosive environments.

Investment Casting with 4140, 8620 and Tool Steels

Not every application requires stainless steel. Different alloy steels may be preferred for components requiring high mechanical strength, wear resistance, or heat-treatment capability.

KHD's production capabilities include heat-treatable steels such as 4140, case-hardening steels such as 8620, and various tool steels.

Material selection should take into account the operating loads, impact conditions, wear environment, temperature, and required heat treatment of the component.

In Which Industries Is Investment Casting Used?

Investment cast components are not limited to a single industry. Thanks to the geometric design freedom and ability to work with a wide range of alloys, the process is used in numerous industrial fields.

Investment Cast Components for the Automotive Industry

Durability, repeatability, and dimensional accuracy are highly important in the automotive industry. Caliper components, guides, bushings, hinges, components associated with fuel systems, and various other automotive parts can be manufactured using investment casting.

Automotive investment casting is particularly useful as a production alternative for complex geometries that need to be manufactured in series.

Investment Casting for the Machinery Industry

Machinery manufacturers may require components with a wide variety of geometries, ranging from gears and holders to blades and special fastening components.

Investment casting for the machinery industry can enable components that would otherwise require numerous machining operations to be produced close to their final geometry.

Investment Casting for the Defense Industry

Equipment used in the defense industry may require components made from various steel grades, with high strength and complex geometries.

KHD can manufacture metal components for use in various defense equipment using theinvestment casting process.

Investment Casting for Medical and Orthopedic Applications

The medical industry is one of the application areas where geometric details and material properties are particularly critical. Cobalt-based alloys and stainless steels such as 316L can be used in various medical applications.

Medical investment casting offers significant advantages for the repeatable production of metal components with complex geometries.

Investment Casting for the Food Industry

Metal components used in food-processing machinery may require properties such as corrosion resistance, durability, and cleanability.

Food industry investment casting using 304, 304L, 316, and 316L stainless steels can be used for mixer components, fans, and various machine components.

Investment Cast Components for Valves and Pumps

Some components used in valves and pumps have complex flow geometries. Therefore, investment casting is a suitable manufacturing alternative for valve and pump manufacturers.

Valve and pump investment castings can be produced from materials such as stainless steel, bronze, and aluminum bronze.

Investment Cast Components for Agricultural Machinery

Agricultural machinery operates under demanding conditions, making component durability essential. Special components used in balers, seed drills, and various agricultural equipment can be manufactured using investment casting.

Investment Cast Components for Textile Machinery

Moving and specially shaped metal components used in textile machinery are also among the applications of investment casting technology.

Production based on technical drawings or samples enables solutions to be developed for new machine manufacturing as well as spare-part requirements.

What Are the Advantages of Investment Casting?

The main reason investment casting is preferred for industrial production is not only its surface quality. Its design flexibility and ability to produce components close to their final geometry also provide important advantages.

Thanks to the ability to manufacture complex geometries, some components that would otherwise need to be produced and assembled separately can be designed as a single casting. This can reduce the need for welding, assembly, or extensive machining.

In addition, reducing material waste through appropriate component design and achieving repeatable geometries in serial production can contribute to manufacturing efficiency.

Investment Casting or Machining?

Investment casting and machining are not necessarily competing processes; they can complement one another.

While direct machining may be suitable for low-volume components with simple geometries,investment casting can offer significant cost and production advantages for complex components manufactured in series.

With investment casting, a component can be produced close to its final dimensions, followed by CNC machining only in critical areas.

This approach can help reduce total machining time, particularly in serial production.

Why Is Quality Control Important in Investment Casting?

The external appearance of a casting alone is not sufficient. The chemical composition of the alloy and the mechanical properties of the component must also meet the requirements of the application.

Within KHD's manufacturing infrastructure, samples can be taken from molten metal for chemical analysis. In addition, physical tests, microscopic examinations, and dimensional inspections can be performed.

Investment casting quality control is particularly important in serial production for monitoring whether components comply with specified technical requirements.

Chemical Analysis and Spectrometer Control

Knowing only the commercial name of the metal used during casting is not sufficient. The elements forming the alloy must be present within specified proportions.

Using a chemical analysis spectrometer, a sample taken from the molten metal can be analyzed and the conformity of the alloy's chemical composition with the target specification can be evaluated before casting.

This control is an important stage of product quality assurance, particularly forsteel investment casting, stainless steels, and special alloys.

Dimensional and Tolerance Control in Investment Casting

Although investment casting can provide high dimensional accuracy, the achievable tolerance is not the same for every component.

Part size, geometry, wall thickness, material, and cooling behavior can affect tolerances. Therefore, it is important to specify critical dimensions on the technical drawing and evaluate them before production.

Where very tight tolerances are required, critical areas can be brought to their final dimensions through post-casting machining or grinding.

Investment Casting Production in Konya

Konya is one of Türkiye's important industrial centers, with a strong manufacturing infrastructure in automotive supply, machinery, agricultural machinery, defense, and metalworking.

KHD, operating in theinvestment casting industry in Konya, carries out its manufacturing activities at its facility in the Konya Organized Industrial Zone.

The concentration of different industries in the same region creates an important manufacturing ecosystem for technical component development, metalworking, and serial production processes.

Investment Cast Components from 1 Gram to 50 Kilograms

Investment casting is not limited to the production of small components. With suitable mold, alloy, and casting infrastructure, components of different weights can be manufactured.

With its manufacturing infrastructure, KHD can developinvestment casting solutions for components ranging from 1 gram to 50 kilograms.

This wide production range allows projects ranging from small machine components to larger industrial components to be evaluated within the same manufacturing approach.

The Importance of Investment Casting in Serial Production

Being able to produce a component as a prototype is important, but being able to reproduce it consistently at the same quality level in serial production is equally important.

Once the mold system has been established, multiple wax patterns of the same component can be produced. This structure contributes to geometric repeatability in serial production projects.

KHD's production capacity and induction furnaces with different capacities enable the development of different production plans for prototype and serial production projects.

What Should Be Considered When Choosing an Investment Casting Manufacturer?

When selecting aninvestment casting company, price should not be the only consideration. Material diversity, quality control infrastructure, mold design capabilities, production capacity, and the ability to manage post-casting operations are also important.

Especially for the serial production of technical components, involving the manufacturer from the design stage can provide significant advantages in terms of manufacturability.

Evaluating mold design, alloy selection, casting process, heat treatment, and machining as an integrated process can result in a more controlled manufacturing operation.

Investment Casting Based on Technical Drawings

In industrial projects, components to be manufactured are generally evaluated based on technical drawings. Technical drawings specify the dimensions, tolerances, material, and critical surfaces of the component.

KHD can evaluate the manufacturability of components using the investment casting process based on technical drawings or samples provided by customers and develop project-specific solutions.

Especially during the design stage of components intended for serial production, consideringdesign for investment casting principles can provide advantages in terms of both product quality and manufacturing costs.

Why Is Investment Casting Preferred?

Investment casting has an important place in modern industry because it brings together complex component geometries, material diversity, surface quality, and serial production capabilities within a single manufacturing method.

Many metal components used in automotive, machinery, defense, medical, food, agricultural, textile, and valve and pump industries can be manufactured using theinvestment casting process.

When the correct alloy selection, appropriate mold design, controlled casting, and effective quality control processes are combined, investment casting provides a powerful solution for the production of high-value technical components.

Frequently Asked Questions About Investment Casting

What is investment casting?

Investment casting is a metal component manufacturing process based on coating a wax pattern with a ceramic shell and pouring molten metal into the cavity created after the wax is removed. It is also internationally known as investment casting or lost wax casting.

Are ceramic casting and investment casting the same?

In the industry, the terms investment casting and ceramic casting may both be used for the investment casting process based on a ceramic shell.

What materials are used for investment casting?

Carbon steels, alloy steels, stainless steels, tool steels, copper alloys, nickel alloys, and other castable metal alloys suitable for the project can be used in investment casting production.

Can stainless steel be investment cast?

Yes. Various stainless steel grades, including 304, 304L, 316, 316L, 410, 420, and 430, can be produced using the investment casting process. The appropriate grade should be selected according to the operating conditions of the component.

Which industries use investment casting?

Investment cast components are used in the automotive, machinery, defense, medical and orthopedic, food-processing machinery, textile machinery, agricultural machinery, valve and pump, and various industrial equipment sectors.

What are the advantages of investment casting?

The ability to produce complex geometries, high surface quality, dimensional accuracy, a wide range of alloy options, and components close to their final geometry are among the main advantages of investment casting.

Can CNC machining be performed after investment casting?

Yes. Areas requiring critical tolerances can be brought to their final dimensions through CNC machining, grinding, or other machining processes after investment casting.

Can heat treatment be applied to investment castings?

Yes. Depending on the steel grade and the required mechanical properties, appropriate heat treatment processes can be applied after casting.

Is investment casting suitable for small components?

Yes. Investment casting is widely used for producing small and complex components, while larger components can also be manufactured with suitable production infrastructure.

What weights of investment cast components can KHD produce?

According to KHD's stated production capabilities, investment cast components ranging from 1 gram to 50 kilograms can be manufactured.

Is investment casting available in Konya?

Yes. KHD Hassas Döküm manufactures investment casting and ceramic casting components for various industries at its production facility in the Konya Organized Industrial Zone.

Can investment cast components be produced from technical drawings?

Yes. The component's technical drawing, material information, tolerances, and operating conditions can be evaluated to develop the mold and production plan required for investment casting.

Is investment casting suitable for serial production?

Yes. Once the mold and process conditions have been established, the ability to reproduce the same component consistently makes investment casting a suitable manufacturing method for serial production.

How is the price of an investment cast component determined?

The price depends on many factors, including component weight, geometry, alloy, production volume, mold structure, tolerances, heat treatment, machining, and surface treatments. Therefore, investment casting component pricing is generally determined after reviewing the technical drawing or sample.