Exam Paper Layout

Higher Level Leaving Cert Engineering

(Answer Question 1 - Section A and Section B and four other questions)

Each Question = 50 marks...............6 x 50 = 300 marks.

(Remember 50% of the Exam is already complete with Practical and Project)

Project 150 marks 25%

Practical 150 marks 25%

Theory 300 marks 50%

Read the paper fully before you start answering any questions, select your questions carefully.

Do not leave the exam early. Do any extra question if you have extra time. Examiner will mark all answers.

Answer Question 1 - Section A and Section B and four other questions.

Draw diagrams in pencil to help illustrate your answer and label diagrams. Draw neat and accurate graphs.

Start each question on a new page and label all parts clearly. Use bullet points.

Look over past exam papers, marking schemes and sample answers on www.examinations.ie

Question 1 - Section A

Section 1 (Short Questions – Summary of the Course, look over past exam papers, marking schemes and sample answers on www.examinations.ie)

Safety symbols, safety with toxic materials, effects of toxic materials, disposal of waste plastic

Corrosion, sacrificial protection, oxidation, electro-chemical corrosion, environment corrosion, protection against corrosion – protective coating (paint, plastic dipping),

anodising of aluminium, hot dipping, electro painting, galvanising

Joining materials with adhesives, preparing materials for joining with adhesives, joint design, types of adhesives, safety hazards when using adhesives

Joining Methods – Mechanical Joining (screw fasteners, compression joints, riveting, sheet metal folding), Welding, Bonding (soldering, brazing, adhesive bonding)

Manufacturing processes – drop forging, calendaring, casting (pattern), sand casting, investment ‘lost wax’ casting, die casting, gravity die casting, pressure die casting,

continuous casting, extrusion, drop forging, press forming, blanking, piercing, punching, bending, drawing, deep drawing

Robots in industry – assembly lines, multipurpose capabilities, production, advantages & disadvantages, work envelope, safety

Machining – generating, forming, shaping, turning, milling

Pneumatic symbols - 3-2 valve (three port valve), 5-2 valve (five port valve), double & single acting cylinders, push button switch, roller switch, lever switch, plunger switch, solenoid

operation, pressure sensitive switch, air supply, exhaust, spring return, reservoir, shuttle valve, flow regulator (see diagram)

Forces - torsion, shear, compression, tension, bending

Thread forms

Electrical symbols – LDR, LED, capacitor, thermistor. Electronic terms – heat sink, breadboard

Separation of ores – pyrometallurgy, hydrometallurgy, thermo-electrometallurgy

Inventors - (see table below)

Ore dressing/ore concentration – flotation, magnetic separation, amalgamation, metal extraction, smelting & refining, reduction, reduction-oxidation

Mining – open cast mining, underground mining, open pit mining, dredging in shallow water, solution mining

Types of materials – polymers, metals, elastomers

Properties of materials – tensile strength, shear strength, malleability, creep, hardness, toughness, ductility, elasticity, electrical conductivity, thermal conductivity, thermal

expansion, compressive strength, density, proof stress, magnetic characteristics, resistance to corrosion, colour, machinability, melting point

Crystal defects (vacant site, substitute defect, interstitial defect), line defects dislocation), covalent bonding, ionic bonding, metallic bonding, crystal patterns - FCC, BCC,

CPH, slip in BCC & FCC, crystalline & amorphous structures, dendritic growth, allotropy, crystal structures

Computer terms – CPU, CD-RW, E-mail, Input & output devices, hardware & software, RAM, ROM

Measuring instruments – limits, tolerance and allowances, limits & fits – (hole & shaft basis of fits), clearance, transition and interference fits

Linear measuring instruments – vernier callipers, micrometer, slip gauges, sine bar, precision cylinders & precision balls, gap gauge, plug gauge

Mechanisms – cams & follower, gears (rack & pinion, worm & wormwheel, bevel gears, gear train, idler gear), crank and slider

Corrosion of Metals – Oxidation, electro-chemical corrosion, sacrificial/cathodic protection, stress corrosion, protection against corrosion (corrosion resistance, anodising

of aluminium, painting, plastic coating, hot dipping, powder cementation, metal spraying, metal cladding, electro-plating), corrosion prevention factors

Pneumatic symbols

Question 1, Section B - Specialist Topic

Nuclear Power

Question 2 - MATERIAL TESTING

Destructive Testing

Toughness - Izod and Charpy (how the test piece is held)

Hardness – Brinell and Vickers (type of indentor)

Principle of the test

Type of indentor

How the test piece is held, How the tests are set up

Advantages

Expected results

Tensile Testing - Draw graph (stress v strain), Stress, Strain, Proof Stress, Young’s Modulus,

Elastic Limits, Modulus of Elasticity, Tensile Strength, specimen used in test

Non Destructive Testing (NDT)

Visual Inspection / Thermal Testing / Ultrasonic / Radiographic or X-Ray / Magnetic Particle /

Dye Penetrant / Eddy Current Testing

Name the test, purpose/principle of the test, what materials (ferrous/non ferrous metal), test

procedure, type of flaws (surface, just below surface, internal), results

Fatigue, fatigue failure, creep, micro and macro examination, ductile and brittle fracture

Question 3 - IRON – CARBON EQUILIBRIUM DIAGRAM (FERROUS METALS)

Label regions on Iron - Carbon Diagram and describe structure - ferrite, pearlite, austenite,

cementite, martensite, eutectic point, solidus line, liquidus line, liquid (page 58 & 59 in text book)

Heat Treatments

Hardening, Flame Hardening, Induction Hardening, Age Hardening, Case Hardening, Carburising,

Annealing, Normalising, Tempering, Quenching, Stress Relieving, Soaking

Solid Solution Alloys (interstitial, substitution)

Upper and lower critical temperatures, eutectic and eutectoid points, allotropy of carbon steel

Instruments for measuring temperature in furnace – thermo-electric or thermocouple pyrometer

and optical pyrometer, describe how pyrometer operates

Blast furnace (iron), electric arc & basic oxygen furnace (steel,) open hearth furnace, cast iron,

cupola furnace, cast iron moulding, grey cast iron and white cast iron

Question 4 - THERMAL EQUILIBRIUM DIAGRAMS (NON FERROUS METALS)

Be able to label diagrams, state what lines represents, mark eutectic point on graph

Solvus line, liquidus line, solvus line, cooling curve, latent heat of fusion

Solid solution alloys - substitutional solid solution and interstitial

Stages of Metal Solidification. Allotropy of iron – BCC

FCC / BCC

Atomic imperfections in metals, line defects in crystals (dislocation), slip in BCC and FCC, crystal

point defects (vacant site (vacancy), substitute defect, interstitial defect), solidifying metal,

dendritic growth, allotropy - FCC, BCC, CPH, crystalline & amorphous structure, bonding of atoms

– covalent, ionic/electrovalent and metallic, states of matter (solid, liquid, gas)

Question 5 - WELDING

Manual Metal Arc Welding (MMA), Gas Welding, Tungsten Arc Gas Shielded Welding (TAGS),

Metal Arc Gas Shielded Welding (MAGS), Seam Welding, Electro Slag Welding, Oxy Acetylene

Welding, Submerged Arc Welding, Resistance Welding, Resistance Spot Welding, Resistance

Seam Welding

Name the process, equipment required, method of operation, applications (uses)

MMA - function of electrode, function of slag, electrode coating, bridge rectifier, transformer,

ground clamp, safety (flashback arrestor)

TAGS – non consumable tungsten electrode, inert gas shields the weld, filler metal is required and

is feed by hand, used to weld aluminium and stainless steel

MAGS – electrode is a bare wire and is fed continuously from a spool through the welding gun,

weld is shielded by inert gas, no slag, often performed by robots, used for car assembly

Oxy Acetylene - identify and explain equipment, dissolved acetylene, oxidising, carburising and

neutral flames, gas hose pipes, flashback arrestors, welding torch, gas pressure regulators,

pressurised cylinders of gas, dissolved acetylene

Multi-run, single run welds, function of the slag, electrode coating, safety precautions when

welding, preparation of materials for welding, transformer, rectifier

Advantages of Robots, work envelope, applications, advantages of robots, safety factors when

using robots, industries where robots are used, work envelope, advantages of using robots in

electrical circuit industry

Question 6 – POLYMERS AND POLYMERISATION

Natural plastics (amber, animal horn, natural rubber, shellac), Modified natural plastics (cellulose, casein), synthetic plastics (by-products of coal)

Stabilisers, catalysts, promoters, inhibitors, plasticisers, colour pigments, antioxidants, flame, retardants, lubricants, fillers

cross-linking, van der vaals forces, monomers, elastomers

Additional, condensation polymerisation and copolymerisation + diagram

Vacuum forming, blow moulding, injection moulding, compression moulding, rotational moulding,

transfer moulding, calendaring, extrusion, welding, machining, lamination, foaming. Name process, type of polymer used, describe process, application, end product

3 main groups of polymers – thermoplastics, thermosetting, elastomers – chemical bonding,

internal structure and properties

Additives – fillers, plasticizers, colour pigments, stabilisers, antioxidants, flame retardants,

lubricants

Thermoplastics (polyethylene, ABS, acetals, polypropylene, PVC, polystyrene, PTFE, Polyamides,

polymethymethacrylate)

Thermosetting (bakelite, amino plastics, epoxy resin, polyesters, polyurethanes, silicones,

elastomers)

Question 7 - MACHINING

Milling – parts of milling machine, types of milling machines (horizontal, vertical universal, turret)

milling cutters, up-cut & down-cut milling, gang & straddle milling, work-holding (direct clamping,

machine vice, dividing head, rotary table, magnetic chuck

Shaping – parts of shaping machine, shaping operations, set-up of machine, work holding, quickreturn

feature, table feed mechanism

Grinding – parts of grinding machine, grinding wheel (abrasive, bond, grade, structure), wheel

mounting, loading, glazing, dressing of grinding wheel, balancing of grinding wheel, surface &

cylindrical grinding, internal grinding, work-holding (magnetic chuck, universal vice, sine chuck)

Turning – parts of the lathe, wedge, rake & clearance angle, shear plane, chip formation

(continuous, discontinuous, BUE), measuring forces on cutting wheel (dynamometer), tool wear

(flank, crater, spalling/chipping, plastic deformation), tool life, machinability, cutting forces,

surface finish, Cutting forces - orthogonal (axial, tangential force) and oblique cutting (axial,

tangential & radial force), working holding (collet chuck, faceplate, three & four jaw chuck,

mandrels, turning between centres, lathe steadies), processes (parallel turning, facing, form

turning, drilling, parting off/grooving, boring, taper turning, knurling, screw cutting), cutting data

(cutting speed, spindle speed, cutting depth, feed rate)

Cutting Fluids – reduce friction & head between work & tool, flush away chips

Workholding – magnetic chuck, chuck block, universal vice, sine chuck

Cutting Tool Material – Carbon steel, high speed steel, cemented carbide, cast alloys, ceramics,

cubic boron nitride, diamond

Forming and generating

Clearance, interference fit, limits & fits

Metrology - direct and comparative measurements (measuring instrument & gauges page 3)

CNC machining – G codes, M codes, canned cycles, pecking, absolute & incremental dimensioning,

test run, tool part position, advantages & disadvantages, safety, compare CNC to manual lathe,

stepper motor

Question 8 – GENERAL MECHANISMS

Mechanisms – Gears (rack & pinion, worm & wormwheel, bevel gears, gear train, idler gear), crank

and slider, cam & follower, ratchet & pawl, universal joint, pulleys, non return valve, dividing head,

slider crank mechanism, quick return mechanism, power hacksaw

Mechanical Joining – screw fasteners

Electronic circuits – explain how the circuits operates

Measuring instruments – limits, tolerance and allowances, limits & fits – (hole & shaft basis of

fits), clearance, transition and interference fits

Linear measuring instruments – vernier callipers, micrometer, slip gauges, sine bar, precision

cylinders & precision balls, gap gauge, plug gauge

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