IMR Materials Testing Technical Blog

By Bruce Reeves

The first 3D printer was invented in 1983, but despite its revolutionary potential, it was not immediately adopted. Early models were cost-prohibitive and functionality limited, making them impractical for most manufacturers. However, technological advancements over the decades have significantly reduced cost and improved capabilities, allowing 3D printing to evolve from a niche tool to a cornerstone of modern manufacturing. 

Today, 3D printers are accessible and versatile, capable of bringing complex designs to life using materials like metals, plastic, epoxies and ceramics. This shift has expanded the applications of additive manufacturing far beyond rapid prototyping to include large-scale production of intricate, end-use parts. 

How Additive Manufacturing Works

At its core, additive manufacturing uses CAD drawings or other digital blueprints to create objects layer by layer. These layers, often measured in microns, allow for exceptional precision. Unlike traditional machining, additive manufacturing minimizes material waste and can meet strict design specifications with ease. 

Industrial 3D printers now offer faster production times and enhanced affordability, enabling manufacturers to embrace additive methods for innovative, cost-effective solutions. 

Common Additive Manufacturing Methods

Each additive manufacturing method has unique advantages, making it suitable for specific applications. Below are some widely used techniques:

Power Bed Fusion

Powder bed fusion printers employ a laser or electron beam to melt a layer shape into a bed of powder. Additional powder is spread over the top for the creation of a new layer and the process is then repeated. Each layer of melted powder binds together to create a pre-programmed design. This process often uses metals or alloys to build sophisticated working parts. 

Selective Laser Sintering (SLS)

This process uses un-sintered powder partially melted with a laser. The unfused powder acts as a support structure during the build, eliminating the need for additional support designs. It’s fas and ideal for functional parts and prototypes and end-use parts. 

Selective Laser Melting (SLM)

Similar to SLS but it fully melts metallic powders with a high powered laser for stronger components with fewer voids, suitable for intricate geometries and thinner walls.

Electron Beam Melting (EBM)

Employs an electron beam to melt and fuse metallic powders. It’s often used in demanding applications like aerospace due to its ability to characterize material properties under various conditions. 

Directed Energy Deposition (DED)

These methods use a focused energy source, such as a laser or electron beam, to melt material as it’s deposited. 

Wire Arc Additive Manufacturing (WAAM)

Unlike powder-based methods, WAAM melts metal wire using an electric arc and a robotic arm extrudes the melted wire onto a substrate, building the part layer by layer with high precision. It’s one of the fastest AM methods and is ideal for large-scale components and repairing parts. 

Vat Polymerization

These methods use a liquid photopolymer resin in a vat which contains photopolymer resin, and an ultraviolet or UV light cures and hardens the resin according to the design, while a platform moves the object downward after every new layer cures. Wherever the resin and UV light come into contact with each other, the resin hardens, forming the final design layer by layer.  

Stereolithography (SLA)

Creates finely detailed shapes by heating liquid photopolymers into semi-liquid form and solidifying them layer by layer. 

Digital Light Processing (DLP)

Similar to SLA  but uses arc lamps instead of UV light, allowing faster print times and high-resolution prototypes. It involves applying an organic coating to a thin photosensitive metal resin before exposing it to a computer-driven UV projector. The automated projector casts UV light onto the resin in the form of the programmed design, each layer is formed and dried in this way until the design is completed. The item is then heated in an industrial oven to remove the organic coating material, leaving a smooth and finished final product. 

MATERIAL EXTRUSION

This category involves pushing a material through a nozzle to build an object. 

Fused Deposition Modeling (FDM)

Popular for functional prototypes and jigs, offering excellent strength-to-weight ratios. 

BINDER JETTING (BJ)

This process uses a liquid binding agent to bond a powdered material, layer by layer. The printer nozzles extrude a liquid binder onto a powder bed.  A new layer of powder is then swept over the fixture and the process repeats. This method can use a wide array of materials, including metals. 

SHEET LAMINATION

Using ultrasonic welding, sheet lamination connects small, thin sheets of material to form specialized designs. Components created through sheet lamination are unique from other 3D-printed objects in that they typically require additional CNC machining before being ready for market.

Laminated Object Manufacturing (LOM)

This rapid prototyping system uses heat and pressure to cut and fuse laminated layers of plastic or paper. It is one of the fastest and most affordable prototyping systems available. 

OTHER ADDITIVE MANUFACTURING METHODS

Material Jetting (MJ)

Also known as wax casting, this method is similar to an inkjet printer. It deposits droplets of material, like polymers or waxes, onto a build platform and cures each layer with a UV light. It’s used to produce high-resolution parts for industries like dental and jewelry. 

Direct Metal Laser Sintering (DMLS)

This is a highly accurate form of metal 3D printing that uses a laser to heat and form metal powders into complex shapes. Parts made with DMLS are more durable and affordable than parts created by machining and are therefore often used in industries like aerospace and medical devices.

Applications and Benefits of Additive Manufacturing

Applications

Industries such as aerospace, medical devices, and custom manufacturing use additive methods for complex, specialized parts. For instance, medical sectors create custom implants, while aerospace manufacturers produce lightweight, durable components.

Benefits

• Innovation: Rapid prototyping accelerates the design process, enabling quick iterations. 
• Cost Efficiency: Scalable production and reduced waste lower costs compared to traditional methods. 
• Eco-Friendly: Energy-efficient processes with minimal material waste. 
• Educational Access: Provides a platform for upskilling workforces in advanced manufacturing. 

Ensuring Quality Through Materials Testing

The success of additive manufacturing relies on the quality of materials and finished parts. IMR Test Labs offers comprehensive testing services to ensure reliability and performance:

Powder Analysis: 

Verifies purity and quality through chemical analysis, particle size testing, and morphology analysis. 

Finished Parts Testing: 

Includes tensile, compression, impact, and fatigue tests to measure strength and durability. 

Global Testing Facilities:

IMR Test Labs in the U.S., Singapore, and China provide worldwide support. 

Additive manufacturing has revolutionized the production landscape, offering a versatile and efficient alternative to traditional methods. WIth its ever-evolving technology, it continues to drive innovation and solve complex design challenges across industries. To achieve optimal results, thorough materials testing remains essential, ensuring the quality and durability of every 3D-printed part.