MANU2488: Advanced Manufacturing & Mechatronics - Comprehensive Revision

Comprehensive vocabulary review flashcards for MANU2488 Advanced Manufacturing & Mechatronics covering manufacturing systems, machining operations, CNC automation, non-traditional machining, additive manufacturing, casting, polymer shaping, bulk and sheet deformation, joining and assembly, and metrology/quality control.

Processing Operations

Manufacturing operations that transform a work material from one state of completion to a more advanced state by altering its geometry, properties, or physical appearance.

Assembly Operations

Manufacturing operations that join two or more separate components to create a new, integrated entity or subassembly.

Product Variety ($P$)

The measure of different product types, models, or designs produced within a manufacturing plant. Higher product variety typically leads to greater design effort and increased manufacturing setup complexity.

Production Quantity ($Q$)

The annual number of units of a product made by a facility, classified into low ($1$ to $100$ units), medium ($100$ to $10,000$ units), and high ($10,000$ to millions of units) production.

Turning

A conventional material removal operation performed on a lathe where the cylindrical workpiece rotates while a single-point cutting tool traverses parallel to or radially across the axis of rotation.

Milling

A machining operation performed on a mill where a multi-toothed rotating cutter removes excess material while traveling along various coordinate axes relative to the workpiece.

Cutting Speed ($v$)

The linear velocity at which the cutting edge of a tool moves relative to the surface of the workpiece, typically expressed as $v = \frac{\pi D N}{1000}\,\text{m/min}$ or $\text{mm/sec}$.

Feed Rate ($f_r$)

The linear travel speed of the cutting tool into or along the workpiece per unit time ($\text{mm/min}$). For turning and drilling it equals $f_r = f N$, and for milling it equals $f_r = n_t f N$.

Depth of Cut ($d$)

The thickness of material removed by the cutting tool in a single pass ($\text{mm}$). In turning cylindrical stock, it is calculated as $d = \frac{D_0 - D_f}{2}$.

Up Milling (Conventional Milling)

A milling operation mode where the cutter teeth rotate against the direction of the table feed at the cut engagement point, causing chip thickness to start at zero and increase to a maximum.

Down Milling (Climb Milling)

A milling operation mode where the cutter teeth rotate in the same direction as the table feed at the cut engagement point, causing chip thickness to start at a maximum and decrease to zero.

Reaming

A hole-finishing operation performed with a fluted rotary tool (reamer) used to slightly enlarge an existing hole to provide close dimensional tolerances and superior surface finish.

Tapping

A hole-processing operation performed by a tap to cut internal screw threads into a pre-drilled cylindrical hole.

Counterboring

A hole-modification operation that produces a stepped cylindrical hole with a larger diameter opening at the entrance followed by a smaller diameter deeper into the workpiece.

Machinability

The relative ease with which a workpiece material can be mechanically cut, which decreases when materials are extremely hard, strong, brittle, poor heat conductors, or subject to severe work hardening.

Computer Numerical Control (CNC)

A form of programmable automation in which machine movements and processing operations are governed by an internal computer interpreting coded alphanumeric instructions (G-code).

Closed-Loop Control System

A positioning drive system that uses feedback sensors (such as shaft optical encoders) to continuously verify worktable position and dynamically compensate for positioning errors.

Modal Command

A G-code instruction that remains active across subsequent program blocks until explicitly overwritten, superseded, or cancelled by another conflicting command (e.g., G00, G01, G90).

Non-Modal Command

A G-code command that is active only within the specific block in which it is written, such as a dwell command ($\text{G04}$).

Absolute Positioning (G90)

A CNC programming mode where all axis coordinates are referenced relative to a fixed coordinate system origin ($0,0,0$).

Incremental Positioning (G91)

A CNC programming mode where each successive coordinate motion is defined relative to the current tool position rather than an absolute origin.

Workpiece Coordinate System (WCS)

A local coordinate system established by the programmer with its origin ($\text{Program Zero}$) placed on a convenient part datum, accessible via fixture offsets ($\text{G54}$ to $\text{G59}$).

Canned Cycle

A standardized, pre-programmed routine within a CNC controller (such as $\text{G81}$ for hole drilling) that automates repetitive multi-step machining motions using a single block of code.

Non-Traditional Machining Processes

Material removal techniques that shape workpieces using mechanical, electrochemical, chemical, or thermal energy mechanisms without relying on conventional sharp cutting tools.

Chemical Milling (CHM)

A non-traditional chemical machining process that employs chemical etchants to selectively dissolve and remove shallow pockets of metal from unmasked surface areas.

Electrochemical Machining (ECM)

A non-traditional process that removes electrically conductive material through localized anodic dissolution (the reverse of electroplating) using high current density and an electrolyte fluid flow.

Electrical-Discharge Machining (EDM)

A non-traditional thermal removal process that erodes conductive material through high-frequency, spark discharges across a dielectric fluid barrier between an electrode tool and the workpiece.

Abrasive Flow Machining (AFM)

A non-traditional mechanical finishing method where an abrasive-laden viscoelastic polymer medium is extruded under pressure back and forth across workpiece surfaces and internal passages for deburring and polishing.

Water Jet Cutting (WJC)

A non-traditional mechanical cutting process that uses an ultra-high velocity stream of water through a fine orifice to cut soft, non-metallic materials without thermal degradation.

Additive Manufacturing (AM)

A group of manufacturing processes that build solid physical 3D objects directly from CAD digital data by joining and consolidating materials layer-upon-layer.

Stair Stepping

The step-like surface roughness artifact that appears on inclined or curved surfaces in additive manufacturing due to slicing the 3D geometry into finite-thickness horizontal layers.

Support Structures

Sacrificial auxiliary features fabricated alongside an additively manufactured part to prevent overhangs ($\alpha < 30^\circ \sim 45^\circ$) from sagging, assist heat dissipation, and anchor the part against thermal warping.

Stereolithography (SLA)

An additive manufacturing vat photopolymerization process that builds high-resolution polymer parts by selectively curing successive liquid photopolymer layers using an ultraviolet (UV) laser beam.

Fused Deposition Modeling (FDM)

An additive manufacturing material extrusion technique where a continuous thermoplastic filament is heated, melted in an extrusion head, and deposited along toolpaths onto a build bed.

Selective Laser Sintering (SLS)

A powder bed fusion additive manufacturing process where a laser selectively fuses fine particles of polymer powder (such as Nylon) into functional components without needing dedicated support structures.

Expendable Mold Processes

Casting methods where the mold must be destroyed and broken away to retrieve the solidified cast metal part (e.g., sand casting, investment casting, plaster mold casting).

Permanent Mold Processes

Casting methods that utilize durable, reusable metal or refractory molds designed to open and eject multiple successive cast components (e.g., gravity permanent mold, die casting).

Sand Mold Casting

An expendable mold casting method where molten metal is poured into a mold cavity formed by compacting sand mixed with bonding agents around an oversized pattern.

Core

A sand insert placed inside a casting mold cavity before pouring to form internal passages, hollow chambers, and internal geometry within the final cast component.

Riser

A reservoir of molten metal integrated into a casting mold that supplies liquid feed metal to the casting to compensate for volume shrinkage during solidification.

Chvorinov's Rule

An empirical relationship expressing the total solidification time ($T_{TS}$) of a casting as $T_{TS} = C_m \left(\frac{V}{A}\right)^n$, where $V$ is casting volume, $A$ is surface area, $C_m$ is mold constant, and $n \approx 2$.

Solidification Shrinkage

The volumetric contraction that occurs in virtually all metals during phase change from liquid to solid state due to the higher density of the solid crystalline structure.

Thermoplastic Polymers

Polymeric materials comprising linear or branched molecular chains that soften into a viscous liquid when heated and solidify when cooled, allowing repeated thermal reforming and recycling.

Thermosetting Polymers (Thermosets)

Polymer compounds that undergo irreversible chemical cross-linking upon initial heating and curing, forming a rigid 3D macromolecular network that cannot be remelted without degradation.

Elastomers

Polymeric materials with loosely cross-linked spring-like chains capable of undergoing substantial elastic deformation under applied force and snapping back rapidly to their original shape.

Injection Molding

A polymer net-shape manufacturing process where plastic pellets are melted, homogenized by a reciprocating rotating screw inside a heated barrel, and injected at high pressure into a closed mold cavity.

Blow Molding

A plastic shaping process where air pressure inflates a softened extruded tube or preform (parison) against the walls of a mold cavity to mass-produce hollow, thin-walled plastic bottles and containers.

Thermoforming

A plastics process where an extruded flat thermoplastic sheet is heated to its softening temperature and drawn against mold contours using vacuum, air pressure, or mechanical force.

Bulk Deformation Processes

Metal forming operations (rolling, forging, extrusion, wire drawing) characterized by significant plastic deformation and massive shape changes on raw workparts with low surface-area-to-volume ratios.

Sheet Metalworking

Deformation and shearing operations (punching, blanking, bending, drawing) performed on thin metal sheets, strips, or coils possessing high surface-area-to-volume ratios.

Flow Curve

The mathematical representation of a metal's plastic stress-strain behavior during deformation, described by Hollomon's power law: $\sigma = K \epsilon^n$.

Strain Hardening Exponent ($n$)

The exponent in Hollomon's flow curve equation ($\sigma = K \epsilon^n$) that defines the slope of the flow curve on log-log axes and corresponds to the true strain where necking begins.

Strength Coefficient ($K$)

The material constant in Hollomon's flow equation ($\sigma = K \epsilon^n$) equivalent to the value of true stress at a true strain of $\epsilon = 1.0$.

Cold Working

Plastic metal forming carried out at ambient room temperature or below $0.3$ times the melting temperature, imparting strain hardening, enhanced yield strength, close dimensional tolerances, and superior surface finish.

Hot Working

Plastic deformation carried out above the metal's recrystallization temperature ($0.5$ to $0.75$ times melting temperature), eliminating strain hardening ($n = 0$) and allowing extensive shape changes at lower forming forces.

Barreling

The outward convex bulging along the sides of a cylindrical workpiece during open-die compression forging, caused by frictional constraints at die interfaces and thermal chilling in hot forging.

Extrusion

A bulk compression deformation process where a heated metal billet is forced through a die orifice under high ram pressure to produce continuous parts of uniform cross-section.

Blanking

A sheet metal stamping operation where a closed profile punch shears through sheet stock to separate a piece (the blank), which serves as the desired finished product.

Punching

A sheet metal shearing operation where a punch cuts through sheet stock to produce an internal hole or feature, with the sheared-out piece (slug) discarded as scrap.

Welding

A permanent joining process in which contacting surfaces of two or more parts are coalesced by application of heat, pressure, or both, frequently utilizing a filler material.

Adhesive Bonding

A joining method in which a non-metallic adhesive substance adheres to contacting component surfaces across an entire joint area without requiring high processing temperatures.

Proof Strength

The maximum tensile stress that a threaded fastener or bolt can sustain without exhibiting any permanent plastic deformation, functioning similarly to an offset yield strength.

Accuracy

The degree of agreement between a measured value and the true or standard value of the target dimension, indicating the absence of systematic errors.

Precision

The degree of repeatability and consistency achieved across multiple independent measurements of the same quantity under identical conditions, reflecting minimization of random errors.

Resolution

The smallest incremental difference in a physical dimension or feature that a measuring instrument or sensor can reliably detect and display.

Tolerance

The total permissible amount by which a manufactured feature or dimension is legally allowed to vary from its nominal design value ($\text{USL} - \text{LSL}$).

Allowance

The intentional, designed difference in dimension between two mating parts at maximum material condition (tightest fit), determining whether an assembly possesses clearance or interference.

Natural Tolerance Limits

Statistical process control limits defined as $\mu \pm 3\sigma$, encompassing $99.73\%$ of all manufactured parts produced by a stable, normally distributed manufacturing process.

GO/NO GO Gauge

A fixed-limit inspection tool used to rapidly check whether a part feature lies within allowable tolerance limits by requiring the GO end to pass into the feature and the NO-GO end to fail to enter.

Arithmetic Mean Roughness ($R_a$)

The mathematical average vertical deviation of surface roughness asperities measured from the nominal mean centerline over an evaluation length: $R_a = \frac{1}{n}\sum_{i=1}^n |y_i|$.

Mean Roughness Depth ($R_z$)

The average of the maximum vertical peak-to-valley distances measured across individual sampling intervals along a surface profile: $R_z = \frac{1}{n}\sum_{i=1}^n (|y_{\max i}| + |y_{\min i}|)$.