Introduction to Additive Manufacturing 111

1D channel

An additive manufacturing (AM) layer construction method in which a single-point source creates a part layer one line at a time. 1D channel construction is commonly used in material extrusion and directed energy deposition (DED).

1D channel array

An additive manufacturing (AM) layer construction method in which a series of connected single-point sources create a part layer in one pass. 1D channel array construction is used in material jetting and binder jetting.

2 x 1D channel

An additive manufacturing (AM) layer construction method in which two single-point sources create a part layer at the same time. 2 x 1D channel construction is faster than 1D channel construction but is only available with some AM methods, such as vat photopolymerization.

2D channel

An additive manufacturing (AM) layer construction method in which a source creates an entire layer of a part at once. 2D channel construction is faster than other layer construction techniques, but it is currently only available with continuous liquid interface production (CLIP) processes.

3D

Three-dimensional. Having height, width, and depth. 3D computer models are constructed for additive manufacturing (AM) processes.

3D printing

The process of producing a 3D object using a specialized tool that creates successive layers of material. 3D printing must technically involve the use of a print head or nozzle, but the term is often used interchangeably with additive manufacturing (AM).

abrasive finishing

The use of an abrasive, such as sandpaper, to polish and smooth the surface of a part. Abrasive finishing is commonly used to improve the surface finish of an additively manufactured part.

additive manufacturing

AM. The process of successively layering materials to make an object based on a three-dimensional (3D) computer model. Additive manufacturing allows for rapid prototyping, mass customization, and increased part complexity.

additive manufacturing file

AMF. An additive manufacturing- (AM) compatible file format that allows for the creation of more complex shapes and higher part tolerance. Additive manufacturing files are more advanced than STL files.

air blasting

Using compressed air as a cleaning tool. Air blasting is often used to clean excess powder off additively manufactured parts built with the powder bed fusion (PBF) processes.

AM

Additive manufacturing. The process of successively layering materials to make an object based on a three-dimensional (3D) computer model. AM allows for rapid prototyping, mass customization, and increased part complexity.

artificial intelligence

AI. A computer program with algorithms that enable a machine or computer to imitate intelligent human behavior. Artificial intelligence allows machines to perform a process with autonomy.

assembly

The process of combining a series of separate components into a single part. Assembly can be improved using positioning jigs and fixtures.

ASTM International

An organization that publishes standards on a broad range of materials. ASTM International, formerly known as American Society for Testing and Materials, has created seven classifications for additive manufacturing (AM) processes.

automated

Run by a preprogrammed mechanical system with little to no human intervention. Automated machines operate more efficiently and precisely than machines that an operator manually controls.

big area additive manufacturing

BAAM. Additive manufacturing (AM) on a scale that exceeds the typical cubic yard size limitation of most additive manufacturing machines. Big area additive manufacturing machines are capable of creating objects the size of cars or larger.

binder

An adhesive material that holds together two or more other materials. Binder holds together powdered materials to make a solid part in binder jetting.

binder jetting

An additive manufacturing (AM) method in which liquid binder is used to join powdered materials to create parts. Binder jetting can create parts out of metal, polymer, or ceramic.

biomaterials

A natural material that composes a part or all of a living structure. Biomaterials, such as living cells and tissues, can be used in some additive manufacturing (AM) processes.

bonds

Joins securely. An additive manufacturing (AM) process usually bonds one layer of material to the next through heat.

boundary representation

A method in CAD modeling for representing shapes using limits. Boundary representation can divide the interior from the exterior of a part.

build materials

The substance used to create an additive manufactured part. Build material includes metal, plastic, ceramics, and composites.

build platform

The flat surface on which a part is additively manufactured. The build platform can either be a permanent surface from which parts are removed or, as a build plate, a surface that can be removed from the machine once the build is complete.

build rate

The time it takes to build a part or the number of parts that can be made in a set period of time. Build rates, or production rates, for additive manufacturing (AM) are considerably slower than traditional manufacturing.

CAD

Computer-aided design. Computer software used to create a digital model of a part before it goes into prototyping or production. CAD models are converted to an STL format for use by additive manufacturing (AM) machines.

carbides

A chemical compound containing carbon and another element, such as chromium, tungsten, or titanium. Carbides are a type of ceramic.

carbon fiber

A material made from slender, thread-like strands of carbon, a strong nonmetallic element. Carbon fiber is a rigid material with good tensile strength, chemical resistance, and temperature tolerance.

ceramics

A hard, brittle material that can withstand high temperatures and resist corrosion. Ceramic parts can be created through additive manufacturing (AM) methods and processes such as binder jetting.

chemical

Relating to the interaction between substances. Chemical removal of additively manufactured support structures includes dissolving them in a chemical bath.

cladding

A protective layer added to a workpiece to improve corrosion resistance and other beneficial properties. Cladding can be added to traditionally manufactured parts using the additive manufacturing (AM) method of directed energy deposition (DED).

composites

A material made by mixing together two or more of the following groups: metals, plastics, and ceramics. Composite materials are categorized by their matrix, or primary, material.

computer numerical control

CNC. A combination of software and hardware that directs the operation of a machine. Computer numerical control machines are much more precise than their manual counterparts.

computer-aided design

CAD. Computer software used to create a digital model of a part before it goes into prototyping or production. Computer-aided design models are converted to an STL format for use by additive manufacturing (AM) machines.

conceptual models

A nonfunctional model used to physically demonstrate design ideas for a part. Conceptual models are often composed of plastic and made using additive manufacturing (AM) methods such as material extrusion or vat photopolymerization.

continuous liquid interface production

CLIP. An additive manufacturing (AM) process in which a part is built by curing layers of a photopolymer with an ultraviolet (UV) projector. In continuous liquid interface production, the part is drawn out of the vat as the UV projector creates an entire layer in one flash of light.

cures

Causes a material to bond and solidify through heat, time, or chemical means. A laser cures photopolymers in vat photopolymerization processes.

cutting

A machining process that uses a tool to remove material from a workpiece. Cutting is a traditional manufacturing operation.

cutting guides

A device that precisely controls the movement of a cutting tool, such as a drill. Cutting guides can be made with optimized functionality through additive manufacturing (AM) processes.

DED

Direct energy deposition. An additive manufacturing (AM) process in which focused thermal energy is used to melt materials as they are fed or blown through a nozzle. DED is often used with powdered or wire metal.

defects

An imperfection in a part that prevents it from operating correctly. Defects sometimes appear in additive manufacturing (AM) parts when the layers do not adhere to each other correctly.

dense

Solidly compressed. Dense materials tend to be harder than less dense materials.

design for additive manufacturing

DFAM. The methodology of planning, testing, and creating an additively manufactured part that functions optimally. Design for additive manufacturing (AM) allows engineers to mostly focus on part functionality.

directed energy deposition

DED. An additive manufacturing (AM) process in which focused thermal energy is used to melt materials as they are fed or blown through a nozzle. Directed energy deposition is often used with powdered or wire metal.

electron beam

A narrow stream of focused electrons that creates thermal energy. Electron beams are sometimes used in additive manufacturing (AM) methods, including directed energy deposition (DED) and powder bed fusion (PBF).

electroplating

A coating method that uses electricity and a conductive solution to deposit a layer of plating metal on a workpiece surface. Electroplating coats additively manufactured parts in order to improve their properties and appearance.

end-use

Designed to be used directly by a consumer or directly in another manufactured product. End-use products created by additive manufacturing (AM) include medical implants, custom dental devices, and camera equipment.

engineers

A person who designs machines, parts, or other technically complex components or features. In manufacturing, engineers are responsible for designing a part, including creating the exact specifications for that part and deciding how best to build and finish the part.

fatigue resistance

A material's ability to resist failing due to repeated external stress. Fatigue resistance is especially important for parts that move during operation.

FDM

Fused deposition modeling. A material extrusion process that builds parts through extruding successive layers of material. FDM is one of the most accessible and affordable types of additive manufacturing (AM), though it creates parts with poor surface finish and has relatively low build speed.

features

A distinguishing characteristic that performs a function on a part. Features include grooves, shoulders, and hinges, among many others.

feedstock roll

The cylindrical mechanism on a sheet lamination machine that holds and dispenses thin sheets of build material. Feedstock rolls often hold rolls of paper, polymer, or metal.

filaments

An extremely thin strand of material. Filaments of thermoplastic material are used by some material extrusion processes to build parts.

fixtures

A customized workholding device used to position and hold a workpiece during a manufacturing process. Fixtures can be created quickly and optimized through additive manufacturing (AM) processes.

forming

A general category of manufacturing processes that involves bending, separating, or shaping material using punches and dies. Forming is a traditional manufacturing process and includes methods such as rolling and extrusion.

functionality

The ability of a part to optimally perform a set purpose. Functionality is a key design consideration, particularly for additively manufactured parts.

fuse

To blend with other materials to form a single object. An additive manufacturing (AM) process such as directed energy deposition (DED) uses an electron beam to fuse metal powder into a solid object.

fused deposition modeling

FDM. A material extrusion process that builds parts through extruding successive layers of material. Fused deposition modeling is one of the most accessible and affordable types of additive manufacturing (AM), though it creates parts with poor surface finish and has relatively low build speed.

G code

A programming language that uses letters and numbers to form commands for machine tools. G code includes information about the exact shape and size of each layer.

geometric complexity

The linear and curved shapes that characterize a part. Geometric complexity is one of the key advantages of additive manufacturing (AM).

glass

A transparent material made from silica and other materials. Glass parts can be created using an additive manufacturing (AM) process like material extrusion.

gradation

Containing a series of changes in material composition. Gradation allows a part to have different properties at different places in the part.

grinding

A subtractive manufacturing process that shapes parts, improves surface finish, and brings parts into close tolerance. Grinding is used as a post-processing procedure in additive manufacturing (AM).

heat treatment

Controlled heating and cooling processes used to change the structure of a material and alter its physical and mechanical properties. Heat treatment is often used to improve the hardness and durability of an additively manufactured part.

hinges

A mechanical joint that is capable of movement. Hinges can be created as a single integrated part using additive manufacturing (AM) technology.

hole proximity

The location of a hole relative to the edge of a part. Proper hole proximity ensures that the hole is far enough away from the edge of a part to maintain the correct shape.

hybrid manufacturing

A process that uses both traditional and additive manufacturing (AM) to create a finished part. Hybrid manufacturing can involve either using a traditional manufacturing process on a mostly additively manufactured part or vice versa.

implants

A device installed on the surface or inside of a human body, usually through surgery. Implants perform essential functions such as monitoring body functions and supporting nearby organs and bodily structures.

implicit modeling

A type of modeling that uses complex mathematical equations to map every point within the boundaries of a shape. Implicit modeling allows engineers to make a detailed map of desired material gradation in a part.

Industrial Internet of Things

IIoT. A network of physical devices used in manufacturing that contain computing systems that allow them to send and receive data. The Industrial Internet of Things allows devices to exchange data and automate processes without any human intervention.

infill

A cross-hatched or honeycombed structure that can fill the interior of an additively manufactured part. Infill provides a part with additional strength and support.

inorganic compounds

A material derived from nonliving substances such as minerals. Inorganic compounds usually do not contain carbon and are often classified in terms of the elements or groups of elements that they contain.

interface

A control panel and display that an operator uses to interact with and control a machine. Interfaces are unique to each additive manufacturing (AM) machine and require operator training to use.

internal channels

A pathway for air, coolants, or other substances to travel through the inside of a part. Internal channels can be created through additive manufacturing (AM) processes.

isopropyl alcohol

A colorless, flammable chemical compound with a strong odor used to clean and sterilize surfaces. Isopropyl alcohol is often used to clean plastic parts made using vat photopolymerization processes.

jigs

A customized workholding device used to position and hold a workpiece while guiding the location and motion of a tool. Jigs are a type of fixturing that can be created using additive manufacturing (AM).

laser

A device that generates an intense beam of light that can be precisely aimed and controlled. Lasers are used to selectively solidify or combine materials in a number of additive manufacturing (AM) methods, including powder bed fusion (PBF), vat photopolymerization, and directed energy deposition (DED).

lattice structures

A repeating, symmetrical pattern of crossing strips of material that leave diamond- or square-shaped gaps between them. Lattice structures provide excellent strength to a part.

manufacturing system costs

Any expenditure related to the general cost of running an industrial production operation. Manufacturing system costs include practical considerations, such as overhead and distribution costs, as well as discretionary considerations, such as new product development.

markup language

A system that encodes information in a document or computer file by clearly separating that information from the original document or computer file. Markup language is used in advanced additive manufacturing files (AMF) to allow engineers to add more specificity and complexity to a part design.

mass customization

The ability to quickly create a large number of uniquely designed variations on a part. Mass customization is one of the key advantages of additive manufacturing (AM) technology.

mass production

The process of creating a product in large amounts, usually on an assembly line. Mass production occurred as a result of assembly lines used during the second industrial revolution.

material extrusion

An additive manufacturing (AM) method that uses a nozzle to dispense material, usually a thermoplastic filament, onto a build platform. Material extrusion is the most widely used AM process.

material jetting

An additive manufacturing (AM) method in which droplets of build material are selectively deposited onto a build platform. Material jetting systems use a photopolymer that is cured by ultraviolet (UV) light.

mechanical

Relating to the use of physical force. Mechanical removal of additively manufactured support structures includes manually removing them with pliers or other hand tools.

mechanical properties

The collection of properties that describe a material's ability to compress, stretch, bend, scratch, dent, or break. Mechanical properties include hardness, ductility, and tensile strength.

melt pool

An area of liquefied material, usually metal. Melt pools are created in directed energy deposition (DED) in order to fuse powdered metal or metal wire in layers to form a solid part.

metal

A hard, strong material that conducts electricity and heat. Metal powders are used in additive manufacturing (AM) to create solid, finished metal parts.

metal oxides

A chemical compound containing oxygen and metal. Metal oxides, which include aluminum oxides and iron oxides, are a type of ceramic.

mold

A hollow cavity that holds heated liquid material and imparts its shape on the material as it cools. Molds with exceptional accuracy can be created using an additively manufactured prototype as the basis for the model.

molding

Manufacturing processes that involve pouring heated liquid material into a reusable cavity that shapes the material as it solidifies. Molding is a traditional manufacturing process and includes methods such as injection and transfer molding.

networking

The ability for two or more computers to connect and communicate with each other. Networking additionally allows computers to communicate with additive manufacturing (AM) machines.

nozzle

A spout at the end of piping or tubing through which substances are funneled. A nozzle is used to distribute build material during material extrusion.

part complexity

The degree of intricacy in the design of a part. Part complexity can be increased through the use of additive manufacturing (AM) methods and processes.

part integration

Combining discrete pieces of a part into a design that can be manufactured as one complete part. Part integration can lead to optimized part design and reduced production time.

part orientation

The position a part will be manufactured in during an additive manufacturing (AM) process. Part orientation involves balancing part quality and build times.

PBF

Powder bed fusion. An additive manufacturing (AM) method that uses adhesives, heat, or light to bond areas in a container of powdered plastic, metal, ceramic, or other material. PBF may use a variety of different channel configurations.

pellets

A very small, round ball of material. Pellets of thermoplastic material are used by some material extrusion processes to build parts.

photopolymers

A type of fluid plastic that cures and hardens when exposed to light. Photopolymers, or resins, appear to be liquids but are technically viscous solids and are used in material jetting and vat photopolymerization.

physical properties

A set of characteristics that describes how a material responds to environmental, thermal, electrical, and magnetic forces. Physical properties describe how a material reacts to forces other than mechanical forces.

plastic

A lightweight polymer material that has high corrosion resistance, a high strength-to-weight ratio, and a low melting point. Plastics are usually easy to shape and form.

polymers

A material that has long chains of large, linked molecules. Plastics are synthetic polymers.

post-processing

A procedure in which a part is cleaned, improved, or otherwise finished for use by a manufacturer or consumer. Post-processing for additively manufactured parts includes abrasive finishing, heat treatment, and painting.

powder bed

The area of a powder-based additive manufacturing (AM) machine that holds granulated build material and provides or holds the build platform. Powder beds are used in powder bed fusion (PBF) and binder jetting.

powder bed fusion

PBF. An additive manufacturing (AM) method that uses adhesives, heat, or light to bond areas in a container of powdered plastic, metal, ceramic, or other material. Powder bed fusion may use a variety of different channel configurations.

powdered

Turned into a collection of small, uniform, and separate particles. Powdered materials are fused together into a solid part in the various powder bed fusion (PBF) processes.

pressure

The exertion of a mechanical force upon an object. Pressure exerted by a roller can be used to help fuse layers in a sheet lamination operation.

print

A design representing the specific dimensions and production considerations for a part or prototype. Prints are created during the design phase of design for manufacturing (DFM) or design for additive manufacturing (DFAM).

printer head

The moving component on a printer that holds and distributes the part build material. Printer heads are used in material jetting and binder jetting machines.

production costs

Any expenditure directly related to starting or running a manufacturing operation. Production costs include the machine and material purchase expenses.

production rate

The time it takes to build a part or the number of parts that can be made in a set period of time. Production rates, or build rates, for additive manufacturing (AM) are considerably slower than traditional manufacturing.

production speed

The time it takes to turn a workpiece from raw material or stock into a finished part. Traditional manufacturing operations typically have better production speed than additive manufacturing (AM).

proprietary

Designed by a specific company for use only with its own systems. Proprietary software, files, and materials are sometimes used with specific additive manufacturing (AM) machines.

prototypes

A preliminary model of a part used to evaluate the look and performance of a design. Prototypes are used to determine the specifications for the final part.

quality assurance

The overall effort by a manufacturer to ensure all parts and products meet consumer or regulatory standards. Quality assurance is a challenge for additive manufacturing (AM) operations because the layering process can be highly variable.

rapid prototyping

A product development technique in which additive manufacturing (AM) methods are used to create prototypes for a traditional manufacturing operation. Rapid prototyping allows engineers to quickly create a number of prototypes in a short time period, reducing lead time.

raw material

An unprocessed or lightly-processed component used to make the finished part. Raw materials in manufacturing include metal, plastic, and ceramic.

repeatability

The ability of a manufacturing process to produce consistent and uniform results. Repeatability is lower for additive manufacturing (AM) than for traditional manufacturing.

resins

A type of fluid plastic that cures and hardens when exposed to light. Resins, or photopolymers, appear to be liquids but are technically viscous solids and are used in material jetting and vat photopolymerization.

resolution

The fineness of detail in a computer-aided design (CAD) model. Resolution helps determine the surface finish quality of an additively manufactured part, with greater resolution leading to better surface finish.

ribs

A structural component that provides shape and support. Ribs are used to reinforce a thin section of a part, such as a wall.

roller

A cylindrical device used in additive manufacturing (AM) to either deposit and level build material or fuse layers of a part together. Rollers are used to level material in vat photopolymerization and powder bed fusion (PBF) methods and to fuse layers together in sheet lamination methods.

sand casting

The process of making a part by pouring molten metal in a sand mold. Sand casting can produce parts with excellent complexity and functionality when the molds are made using additive manufacturing (AM) processes.

sanding

A gentle grinding process that uses an abrasive with a fine grain, usually sandpaper, to remove small amounts of surface material. Sanding is an abrasive finishing process often used in additive manufacturing (AM) post-processing.

sealing

Applying a water- and air-tight coating to a part. Sealing is often used on plastic parts that will be sold to consumers.

secondary process

Using additive manufacturing (AM) processes to create patterns or molds for parts and tooling rather than final products. Secondary AM processes are sometimes referred to as indirect rapid tooling or indirect rapid prototyping.

sheet lamination

An additive manufacturing (AM) process that forms an object by bonding sheets of material together using an adhesive, heat, or pressure. Sheet lamination processes melt thin sheets of material together, bonding them layer by layer, to form a single three-dimensional object.

shell

The outer layer of an additive manufacturing (AM) part. Shells can vary in thickness at different places on an individual part.

silica

A ceramic compound that is commonly used to make a wide variety of glasses. Silica is used in processes like sand printing.

single-point source

An additive manufacturing (AM) device that layers, sinters, or cures a part layer one small dot at a time. Single-point sources include nozzles and lasers.

slicer

A computer program that divides an STL file into layers for additive manufacturing (AM). Slicers, or slicing programs, can either be separate computer programs or part of the machine interface.

slicing program

A computer program that divides an STL file into layers for additive manufacturing (AM). Slicing programs, or slicers, can either be separate computer programs or part of the AM machine interface.

small-batch production runs

The production of a limited number of parts, usually less than 500. Small batch production runs can be cost-effective using additive manufacturing (AM) technology.

springs

A flexible device that yields under compressive force and returns to its original shape when the force is removed. Springs are used to apply force, control motion, and store energy.

standards

An established policy regarding specific product requirements or a particular practice or method. Standards cover a range of topics, from the required properties of a material to the documentation necessary across the supply chain.

stereolithography

SLA. An additive manufacturing (AM) method in which a part is built by curing layers of a photo-reactive resin with an ultraviolet (UV) laser. Stereolithography is often used for making softer parts that require a high degree of customization such as dental aligners or hearing aids.

STL file

An additive-manufacturing- (AM) compatible file format that represents 3D models as a series of interconnected triangles. STL files are sometimes referred to as stereolithography files, standard tessellation language files, or standard transform language files.

support material

Additional material used in the additive manufacturing (AM) process to support the product as it is being constructed. Support material is removed from the product as part of the AM process.

support structure

A reinforcing component used to hold the weight of an additively manufactured part as it is being constructed. Support structures are removed from the part once the build is complete.

surface finish

The degree of smoothness on a part's outer surface after it has been manufactured. Initial surface finish quality varies depending on the additive manufacturing (AM) process used and the build parameters.

thermal distortion

Deformation caused by exposure to excessive heat. Thermal distortion of parts is a concern for all additive manufacturing (AM) methods and processes that use heat, such as material extrusion or powder bed fusion (PBF) methods.

thermal energy

Energy in the form of heat. Thermal energy is used to fuse materials together in some additive manufacturing (AM) methods, such as directed energy deposition (DED) and powder bed fusion (PBF).

three-dimensional

3D. Having height, width, and depth. Three-dimensional models are constructed for additive manufacturing (AM) processes.

tolerance

An unwanted but acceptable deviation from a given part dimension. Tolerance is, in part, determined by the resolution of the three-dimensional (3D) part model processed by the additive manufacturing (AM) machine.

tooling

Assorted tools used in various manufacturing processes. Tooling that can be created by additive manufacturing (AM) processes includes molds, assembly fixtures, and medical guides.

toolpaths

The series of coordinate positions that determine the movement of a tool during a manufacturing operation. Toolpaths for additive manufacturing (AM) machines are automatically generated by specialized slicing computer programs that analyze the three-dimensional (3D) part model and divide it into layers.

traditional manufacturing

A manufacturing process that involves creating a part by shaping or removing material from a workpiece. Traditional manufacturing operations include metal cutting and forming.

ultraviolet

UV. A potentially harmful wavelength of light that is below, or shorter than, violet on the light spectrum. Ultraviolet light is used to selectively harden a photopolymer in vat photopolymerization processes.

undercuts

A recessed area or depression. Undercuts can be challenging to create with rigid tools or molds but are easy to form using additive manufacturing (AM) processes.

UV

Ultraviolet. A potentially harmful wavelength of light that is below, or shorter than, violet on the light spectrum. UV light is used to selectively harden a photopolymer in vat photopolymerization processes.

UV projector

A device that creates a two-dimensional layer of ultraviolet (UV) light. In CLIP, UV projectors are used to create an entire part layer in a single moment in continuous liquid interface production processes.

vat

An industrial receptacle used to hold fluids. Vats are often used to hold photopolymers in vat photopolymerization.

vat photopolymerization

An additive manufacturing (AM) method in which a part is built by curing layers of a photo-reactive resin with an ultraviolet (UV) laser. Vat photopolymerization is often used for making softer parts that require a high degree of customization such as dental aligners or hearing aids.

visual aids

An object used to illustrate and supplement verbal or written information. Visual aids created using additive manufacturing (AM) include conceptual, construction, and surgical models.

wall thickness

The amount of material in a flat vertical barrier in a part. Wall thickness must fall within certain parameters for different additive manufacturing (AM) processes.

warp

To physically bend, twist, or deform. Warpage can be caused by uneven heating and cooling and by a lack of reinforcement in a part component.

waxes

A malleable, water-resistant organic material with a low melting point. Wax is sometimes used as build or support material during material jetting.

wireless router

A signal-producing device that transmits data through an antenna rather than a network cable. Wireless routers, which are used to create computer networks, operate through radio waves.

workpiece

A material being machined or undergoing another type of processing. A workpiece may be subject to cutting, welding, forming, additive printing, or other operations.