Hybrid Manufacturing with Directed Energy Deposition 261

additive manufacturing

AM. The process of joining or solidifying materials to make an object from a three-dimensional computer model. Additive manufacturing methods typically build up layers of material to create an object.

AM

Additive manufacturing. The process of joining or solidifying materials to make an object from a three-dimensional computer model. AM methods typically build up layers of material to create an object.

asperities

Microscopic peaks found on all surfaces. Contact between asperities on different surfaces causes friction.

automate

Using mechanical systems that operate with limited human interaction. Automated systems include CNC machines and robotics.

automatic tool changer

A CNC mill or machining center component that holds and changes tools during operation. Automatic tool changers reduce cycle times by automatically changing tools between functions.

bearing

A friction-reducing device that allows one moving part to glide past another moving part without excess wear or friction.

blisk

A component made of a rotor disk and multiple attached blades. Blisks, or bladed disks, are commonly used in aerospace parts.

build platform

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

build rates

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. A method of designing two- and three-dimensional objects using computers and software. CAD is most often used to create part models for production.

CAM

Computer-aided manufacturing. The use of computer software that facilitates the development of part programs to produce a part. CAM software applications create an image of the workpiece and develop the program code from information that the programmer inputs.

chuck

A device that holds a workpiece in place as it rotates on a lathe or other machine. The chuck commonly has three or four jaws that can be adjusted to fit various workpieces.

cladding

Adding a protective layer of material to a previously manufactured workpiece to improve corrosion resistance or other beneficial properties. Cladding is traditionally done using welding tools that create a mechanical bond between two similar metals.

clamps

A device that holds an object by applying downward or inward pressure. Clamps are often used as workholding devices in manufacturing.

CNC

Computer numerical control. A programmable system of software and hardware that directs the operation of a machine. CNC systems use mathematical data to direct machine movements.

coatings

The application of surface treatments to a material. Coating processes change a material's mechanical properties.

cobalt

A hard, gray metal that is highly magnetic. Cobalt is often added to manufactured parts or components because of its superior coating and adhesion characteristics.

cold spraying

A process in which powdered materials are sprayed, below their melting point and at very high speeds, onto a surface to protect it from wear, heat, and corrosion. Cold spraying deforms and mechanically bonds the sprayed materials to the intended surface.

computer numerical control

CNC. A programmable system of software and hardware that directs the operation of a machine. Computer numerical control systems use mathematical data to direct machine movements.

computer-aided design

CAD. A method of designing two- and three-dimensional objects using computers and software. Computer-aided design is most often used to create part models for production.

computer-aided manufacturing

CAM. The use of computer software that facilitates the development of part programs to produce a part. Computer-aided manufacturing software applications create an image of the workpiece and develop the program code from information that the programmer inputs.

consumable electrode

A device that conducts electricity from the contact tip to the arc and melts into the weld as a filler metal. Some consumable electrodes may also provide shielding that protects the arc and weld puddle.

DED

Directed energy deposition. An additive manufacturing process in which focused thermal energy is used to melt materials as they are deposited. DED is often used with powdered or wire metal feedstock.

deposition head

A nozzle that melts and dispenses material. Deposition heads are used in directed energy deposition (DED) processes.

directed energy deposition

DED. An additive manufacturing process in which focused thermal energy is used to melt materials as they are deposited. Directed energy deposition is often used with powdered or wire metal feedstock.

electric arc

An area in which electricity jumps from an electrode on a tool to a workpiece or build platform. An electric arc melts the wire feedstock in wire arc additive manufacturing (WAAM).

features

A defining characteristic on a component or part. Features include corners, edges, holes, and grooves.

feedstock

Raw material that is used to make manufactured parts. Feedstock for additive manufacturing methods includes filaments, pellets, wire, and powder.

five-axis

Machine control that can execute movement along three linear axes and two rotational axes. Five-axis machining capabilities can allow hybrid DED deposition heads to access areas of a part that are difficult to reach otherwise.

flange

A ring or collar surrounding a cylindrical component such as a shaft or toolholder. A flange is mounted to other components to provide support and rigidity.

four-axis

Machine control that can execute movement along four axes concurrently. Four axis machines can move machining tools along three linear axes while turning the workpiece around an additional rotational axis.

fused deposition modeling

FDM. An additive manufacturing process that builds objects by extruding layers of material. FDM usually uses thermoplastic materials.

G code

A programming language that pairs address letters with numerical values to form commands. G code is used to direct the path of tools on traditional and hybrid CNC machines.

gas metal arc welding

GMAW. An arc welding process in which the bare wire electrode and inert shielding gas are fed to the weld through a welding gun. Gas metal arc welding tools can also be used in additive manufacturing processes.

gas tungsten arc welding

GTAW. A very precise arc welding process that uses a non-consumable tungsten electrode. GTAW is also referred to as tungsten inert gas (TIG) welding.

ground

A source that absorbs stray electrical charge. Ground may refer to the earth or another large conducting body, such as a motor housing, that serves as a source of zero electrical potential.

hybrid additive manufacturing

Hybrid AM. A process that uses both traditional and additive manufacturing (AM) to create a finished part. Hybrid additive manufacturing involves combining additive and subtractive processes on a single machine.

hybrid machining center

A type of CNC machine that is capable of both additive manufacturing and traditional subtractive machining. Hybrid machining centers typically resemble the basic structure of a traditional CNC mill.

impeller

A rotor inside a tube or conduit used to increase pressure and flow of a fluid. Impellers are sometimes referred to as blowers.

Inconel

A superalloy made of nickel and chromium that is designed to perform well in extreme environments. Inconel is very difficult to machine and resists both oxidation and corrosion.

laser cladding

The process of fusing a layer of material onto a part surface using a laser. Laser cladding fuses together metallurgically, creating a more durable bond than traditional cladding methods.

laser metal deposition

LMD. A directed energy deposition process that uses a laser beam to melt powdered metal as it is deposited on a build platform. Laser metal deposition is sometimes referred to as laser powder forming.

laser scanner

The process of using a concentrated beam of light to generate data about the geometric shape of an object. Laser scanning is used to create a point cloud that can be turned into a 3D computer-aided design (CAD) model.

lathe

A machine used to create parts, often cylindrical, by removing material from a workpiece. A lathe holds a rotating workpiece while the cutting tool is either fed into the workpiece or along its side.

live tooling

A feature that equips the tool posts or turret on a lathe with power-driven tools, such as end mills and drills. Live tools can perform machining operations off the part centerline while the workpiece is held in the spindle.

LMD

Laser metal deposition. A directed energy deposition process that uses a laser beam to melt powdered metal as it is deposited on a build platform. LMD is sometimes referred to as laser powder forming.

M code

Lines of code in the G code programming language. M codes are used to program machine functions, such as coolant or tool changes, and are often machine- or manufacturer-specific.

material hopper

A container used to hold raw materials for use in an industrial process. Material hoppers used in metal AM processes hold powdered metal.

mating parts

An object that a workpiece has been manufactured to fit. Nuts and bolts are mating parts.

mechanical bond

A joining of two material using an adhesive in which the adhesive material physically locks into the crevices of the surface. A mechanical bond is less sturdy than a metallurgical bond.

mechanical properties

A characteristic that describes how a material reacts when subjected to a force that attempts to stretch, compress, bend, dent, scratch, or break it. Mechanical properties include strength, toughness, ductility, and hardness.

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 matrix composites

MMCs. A composite made from a metallic matrix and high-performance reinforcements. MMCs have high levels of strength, stiffness, and relatively high resistance to heat.

metallurgical bond

A joining of two separate metals in a way that combines their physical and mechanical properties. Metallurgical bonds are stronger than mechanical bonds.

microns

A metric unit of measurement equal to one thousandth of a millimeter (0.000039 inches). Microns, also known as micrometers, are used to measure layer thickness for DED processes.

microstructure

The relationship between the small, individual crystals in a metal. Microstructure, also known as grain structure, changes when the metal is exposed to high temperatures.

mill

A rotating, multi-point cutting tool that is guided along a workpiece to create flat surfaces, slots, or other features. The term mill also refers to the machine that uses mills to perform milling operations on a workpiece.

near net shape

A part with dimensions that are close to its final specified form after initial manufacturing steps. Near-net-shape parts require little subsequent machining.

net shape

A part that meets consumer or manufacturer specifications, including tolerance and surface finish, directly after it is manufactured. Net-shape parts do not need any further post processing after they are created.

nickel

A corrosion-resistant nonferrous metal. Nickel is commonly added to electrodes and stainless steels to prevent corrosion.

nonconsumable electrode

An electrode which is not used up during the process of welding. Nonconsumable electrodes are used in GTAW are made from tungsten.

part program

A series of instructions produced by CAM software and used by a CNC machine to perform the necessary sequence of operations to complete a part based on a CAD design. Part programs are typically written in G code.

part zero

The starting point of X, Y, and Z coordinates for a specific workpiece. Part zero acts as a reference point for all part dimensions.

post-processing

A finishing process used to clean, grind, or otherwise prepare a manufactured additive manufacturing part for shipping to a manufacturer or other consumer. Common additive manufacturing post-processing steps include removing support structures, improving surface finish, and bringing the part into tolerance.

powder bed fusion

PBF. An additive manufacturing method that uses thermal energy to melt together layers of powdered polymer, metal, ceramic, or other material. Powder bed fusion processes often use either lasers or electron beams as thermal energy sources.

print head attachment

A portable additive manufacturing component that holds and distributes part build material. Print head attachments can be installed on many traditional CNC machines to convert them into hybrid machines.

resolution

The amount of detail that an AM machine can build in a set amount of space. A higher resolution means that a machine can build more detailed parts.

robotic arm

A programmable or remote-controlled mechanical device that simulates the movement of a human arm. Robotic arms are used in a variety of assembly and manufacturing applications.

shielding gas

A gas that surrounds and protects melted metal from oxidation. Shielding gases are used in some directed energy systems.

spindle

The rotating component of the machine tool. In a milling operation, the spindle holds and rotates the toolholder and cutting tool.

stereolithography

STL. Computer files that represent 3D models as a series of interconnected triangles. Stereolithography files are converted from CAD files and are used in additive manufacturing machines.

substrate

A surface or medium that serves as a base for other materials or components. Some directed energy deposition processes deposit materials onto substrates rather than a build platform.

superalloy

An expensive, complex metal alloy designed to perform under intense conditions, such as elevated temperatures. Superalloys are also known as high performance alloys.

support structures

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.

thermal energy source

A device that generates power in the form of heat. Thermal energy sources, such as devices that generate electron beams, lasers, and plasma arcs, are used during some additive manufacturing methods.

thermal spraying

A process in which heated materials are sprayed, at or above their melting point, onto a surface to protect it from wear, heat, and corrosion. Thermal spraying can mechanically bond metal coatings to an existing surface.

thermal stresses

Damage to a material due to excessive changes in temperature. Thermal stresses may occur during additive manufacturing methods, such as powder bed fusion (PBF) and directed energy deposition (DED), causing a part to warp or distort.

tolerances

An acceptable deviation from a desired dimension that meets specifications. Parts outside of a required tolerance must be discarded or reworked.

tool turret

A lathe component that holds a number of cutting tools. The tool turret rotates to place tools in the cutting position.

toolpaths

A series of coordinate positions that determine the movement of a tool during a machining operation. Toolpaths are expressed in G code.

toolpaths

A series of coordinate positions that determine the movement of a tool during a machining operation. Toolpaths are expressed using G code commands.

touch probe

A type of contact probe that detects a feature on a part and generates an electronic signal to record its dimension. Touch probes are commonly used to create 3D models for DED repair.

turbine

A machine for producing continuous power. A turbine consists of a wheel or rotor made to revolve by a fast-moving flow of water, steam, gas, air, or other fluid.

turning center

A sophisticated CNC lathe that can perform a variety of drilling and milling operations all at the same location. Turning centers usually use live tooling.

variability

Inconsistencies in dimensions from one part to the next when producing the same part multiple times. Variability is a challenge that manufacturers must cope with when producing parts using additive manufacturing methods.

vise

A workholding device with two jaws that grip and hold a workpiece in place. Vises are mostly used to hold rectangular workpieces with fairly simple dimensions.

wear resistance

A material's ability to resist the gradual wearing away caused by abrasion and friction. Increased wear resistance can lengthen the life of a material.

wire arc additive manufacturing

WAAM. A directed energy deposition (DED) process that uses an electric arc and a shielding gas to melt materials as they are deposited onto a build platform. Wire arc additive manufacturing typically uses wire feedstock.

workholding

A method or device for securing a workpiece for a machining operation. Workholding can include chucks, vises, and bolts.