Foseco Non-Ferrous Foundryman’s Handbook Part 1 pdf

Since 1994 the technology of casting has continued to develop and has become more specialised so that it has been decided to publish the 11th edition of the Handbook in three separate vo

Foseco Non-Ferrous Foundryman’s Handbook

Foseco Non-Ferrous Foundryman’s Handbook

Eleventh edition

Revised and edited by

John R Brown

OXFORD AUCKLAND BOSTON JOHANNESBURG MELBOURNE NEW DELHI

The last edition of the Handbook was published in 1994 and like all the earlier

editions, it aimed to provide a practical reference book for all those involved

in making castings in any of the commonly used alloys by any of the usual

moulding methods In order to keep the Handbook to a reasonable size, it was

not possible to deal with all the common casting alloys in detail Since 1994 the technology of casting has continued to develop and has become more specialised so that it has been decided to publish the 11th edition of the

Handbook in three separate volumes:

Non-ferrous dealing with aluminium, copper and magnesium casting

alloys Iron dealing with grey, ductile and special purpose cast

irons Steel dealing with carbon, low alloy and high alloy steels Certain chapters (with slight modifications) are common to all three volumes: these chapters include tables and general data, sands and sand bonding systems, resin bonded sand, sodium silicate bonded sand and feeding systems The remaining chapters have been written specifically for each volume

The Handbook refers to many Foseco products Not all of the products are

available in every country and in a few cases, product names may vary Users should always contact their local Foseco company to check whether a particular product or its equivalent is available

The Foseco logo and all product names appearing in capital letters are trademarks of the Foseco group of companies, used under licence

John R Brown

Acknowledgements

1 Tables and general data 1

SI units and their relation to other units 1

SI, metric, non-SI and non-metric conversions 2

Conversion table of stress values 5

Areas and volumes of circles, spheres, cylinders etc 6

The physical properties of metals 7

The physical properties of metals (Continued) 8

Densities of casting alloys 9

Approximate bulk densities of common materials 10

Patternmakers contraction allowances 11

Volume shrinkage of principal casting alloys 13

Comparison of sieve sizes 14

Calculation of average grain size 15

Calculation of AFS grain fineness number 16

Recommended standard colours for patterns 17

Dust control in foundries 18

Buoyancy forces on cores 18

Core print support 19

Opening forces on moulds 19

Dimensional tolerances and consistency achieved in castings 21

2 Aluminium casting alloys

Introduction

Casting alloys 25

Casting processes 39

The effect of alloying elements 39

Heat treatment of aluminium alloys 42

3 Melting aluminium alloys

Introduction

Raw materials 47

Melting furnaces 47

Corundum growth 54

Choice of melting unit 55

4 Fluxes

Application of COVERAL powder fluxes

Granular COVERAL fluxes 61

5 INSURAL refractory for ladles and metal transport

Ladle liners 65

6 Treatment of aluminium alloy melts

Hydrogen gas pick-up in aluminium melts

Degassing aluminium alloys 72

Grain refinement of aluminium alloys 77

Modification of aluminium alloys 79

Sodium modification 81

Strontium modification 82

Permanent modification 83

Sand, gravity die and low pressure diecasting 83

Medium silicon alloys, 4 7% Si 84

Eutectic silicon alloys, 12% Si 84

Treatment of hypereutectic Al Si alloys (over 16% Si) 85

Melting and treatment of aluminium magnesium alloys ( 4 10% Mg) 86

Special requirements for gravity diecasting 87

Treatment of alloys for pressure diecasting 87

7 Running, gating and feeding aluminium castings 75

Gating without filters 90

Gating with filters 93

Feeding mechanisms in Al alloy and other non- ferrous castings 94

Simulation modelling 98

8 Filtration of aluminium alloy castings

SIVEX FC filters 100

Use of filters in conventional running systems 101

Direct pouring of aluminium alloy castings 104

KALPUR combined sleeve and SIVEX FC filter for aluminium castings 105

Direct pouring into metal dies 107

9 Pressure diecasting of aluminium alloys

Die design

Process control 111

Modification of the diecasting process 113

Applications of diecastings 114

The diecasting foundry 114

Die coating 116

10 Low pressure and gravity diecasting

Low pressure diecasting

Gravity diecasting 124

Die coatings for gravity and low pressure diecasting 127

11 Sand casting processes

Green sand 136

Moulding machines 137

Core assembly sand processes 140

The Lost Foam process 144

12 Sands and sand bonding systems

Properties of silica sand for foundry use

Typical silica foundry sand properties 151

Safe handling of silica sand 152

Segregation of sand 153

Measurement of sand properties 153

Thermal characteristics of silica sand 153

Zircon, ZrSiO4 154

Chromite, FeCr2O4 156

Olivine, Mg2SiO4 156

Green sand additives 157

The green sand system 160

Green sand properties 163

Control of green sand systems 164

Sand testing 165

Control graphs 165

Parting agents 166

Special moulding materials, LUTRON 166

13 Resin bonded sand

Chemically bonded sand

Self-hardening process (also known as self-set, no- bake or cold- setting process)

Testing chemically bonded, self-hardening sands 169

Mixers 171

Sand quality 172

Pattern equipment 172

Curing temperature 173

Design of moulds using self-hardening sand 173

Foundry layout 173

Sand reclamation 175

Typical usage of sand reclamation 178

Furanes 180

Phenolic-isocyanates (phenolic-urethanes) 182

Alkaline phenolic resin, ester hardened 183

Heat triggered processes 185

Gas triggered systems 186

The shell or Croning process 187

Hot-box process 189

Warm-box process 190

Oil sand 191

Phenolic-urethane-amine gassed (cold-box) process 193

ECOLOTEC process (alkaline phenolic resin gassed with CO2) 195

The SO2 process 196

SO2- cured epoxy resin 198

Ester-cured alkaline phenolic system 198

Review of resin core-making processes 199

14 Sodium silicate bonded sand

Sodium silicate

CO2 silicate process ( basic process) 205

Gassing CO2 cores and moulds 207

Improvements to the CO2 silicate process 208

The CARSIL range of silicate binders 209

SOLOSIL 209

Self-setting sodium silicate processes 210

Ester silicate process 210

Adhesives and sealants 215

CORSEAL sealants 215

TAK sealant 215

15 Magnesium casting

Casting alloys

The melting, treatment and casting of magnesium alloys 218

16 Copper and copper alloy castings

The main copper alloys and their applications

Specifications for copper-based alloys 226

Colour code for ingots 227

Melting copper and copper-based alloys 232

Melting and treatment of high conductivity copper 238

Copper-silver 242

Copper cadmium 243

Copper chromium 243

Commercial copper 243

Melting and treatment of brasses, copper zinc alloys 244

Melting bronzes and gunmetals 248

Melting aluminium bronze 250

Melting manganese bronze 250

Melting high lead bronze 250

Melting copper nickel alloys 251

Filtration of copper-based alloys 251

17 Feeding systems

Natural feeders

Aided feeders 253

Feeding systems 254

The calculation of feeder dimensions 257

Steel, malleable iron, white irons, light alloys and copper-based alloy castings 262

Grey and ductile irons 266

Introduction 268

Range of feeder products 269

Breaker cores 279

The application of feeder sleeves 280

Williams Cores 283

FERRUX anti-piping compounds for iron and steel castings 284

Metal-producing top surface covers 285

FEEDOL anti-piping compounds for all non-ferrous alloys 286

Aids ot the calculation of FEEDER requirements 286

Nomograms 287

FEEDERCALC 287

Calculating feeder sizes for aluminium alloy castings 288

Index

Acknowledgements xiii

All statements, information and data contained herein are published as

a guide and although believed to be accurate and reliable (having regard to the manufacturer’s practical experience) neither the manu-facturer, licensor, seller nor publisher represents or warrants, expressly

or implied:

1 Their accuracy/reliability

2 The use of the product(s) will not infringe third party rights

3 No further safety measures are required to meet local legislation

The seller is not authorised to make representations nor contract on behalf of the manufacturer/licensor All sales by the manufacturer/ seller are based on their respective conditions of sale available on request

Tables and general data 3

1 pt (pint) = 0.568261 l

1 US gal = 3.78541 l = 0.832674 gal (imp)

1 ft3/min (cfm) = 1.699 m3/h

1 ft3/sec = 28.3168 l/s

Mass:

1 lb (pound) = 0.453592 kg

1 cwt = 50.802 kg

1 kg = 2.20462 lb

1 oz = 28.349 gm

1 ton = 2240 lb = 1.01605 t (tonne) = 1016.05 kg

1 ton (US) = 2000 lb = 907.185 kg

Force:

1 kgf = 9.80665 N = 2.20462 lbf = 1 kp (kilopond)

1 lbf = 4.44822 N

1 pdl (poundal) = 0.138255 N

Density:

1 kgf/m3 = 0.062428 lb/ft3

1 lb/ft3 = 16.0185 kg/m3

1 g/cm3 = 1000 kg/m3

Pressure, stress:

1 kgf/cm2 = 98.0665 kPa (kN/m2)

1 kgf/mm2 = 9.80665 N/mm2 = 1422.33 lbf/in2 = 0.63497 tonf/in2

1 lbf/in2(psi) = 6.89476 kPa (kN/m2)

1 Pa (N/m2) = 0.000145038 lbf/in2

1 in w.g (in H2O) = 249.089 Pa

1 N/mm2 = 1 MPa = 145.038 lbf/in2 = 0.06475 tonf/in2

= 0.10197 kgf/cm2

Power:

1 kW = 3412 Btu/hr

1 hp (horsepower) = 0.745700 kW

Energy, heat, work:

1 Btu = 1.05506 kJ

1 cal = 4.1868 J

1 kWh = 3.6 MJ = 3412 Btu

1 therm = 100 000 Btu = 105.506 MJ

1 kJ = 0.277778 W.h

Specific heat capacity, heat transfer:

1 cal/g°C = 1 kcal/kg°C = 4186.8 J/kg.K

1 Btu/lb°F = 4186.8 J/kg.K

1 Btu/h = 0.293071 W

4 Foseco Non-Ferrous Foundryman’s Handbook

1 cal/cm.s°C = 418.68 W/m.K (thermal conductivity)

1 Btu.in/ft2h°F = 0.144228 W/m.K (thermal conductivity)

1 Btu/ft2h°F = 5.67826 W/m2.K (heat transfer coeff.)

Miscellaneous:

1 std.atmos = 101.325 kPa = 760 mm Hg = 1.01325 bar

1 bar = 100 kPa = 14.5038 lbf/in2

1 cP (centipoise) = 1 mPa.s

1 cSt (centistoke) = 1 mm2/s

1 cycle/s = 1 Hz (Hertz)

1 hp = 745.7 W

Useful approximations:

⁄4lb

1 gal = 41⁄2l 1 std atmos = 1 bar

1 ha = 21⁄2acre 1 km = 5⁄8mile

1 hp = 3⁄4kW 1 litre = 13⁄4pint

1 tonf/in2 = 15 N/mm2

1 psi (lbf/in2) = 7 kPa

1 N (newton) = the weight of a small apple!

Temperature:

°F = 1.8  °C + 32

°C = (°F – 32)/1.8

0°C (Celsius) = 273.15 K (Kelvin)