Preface
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
The following Organisations have generously permitted the use of their
material in the Handbook:
The American Foundrymen’s Society, Inc., 505 State Street, Des Plaines,
Illinois 60016-8399, USA.
The Association of Light Alloy Founders (ALARS), Broadway House,
Calthorpe Road, Five Ways, Birmingham, B15 1TN.
BSI, Extracts from British Standards are reproduced with the permission of
British Standards Institution. Complete copies can be obtained by post
from Customer Services, BSI, 389 Chiswick High Road, London W4
4AL.
Buhler UK Ltd, 19 Station Road, New Barnet, Herts, EN5 1NN.
Butterworth-Heinemann, Linacre House, Jordan Hill, Oxford OX2 8DP.
The Castings Development Centre (incorporating BCIRA), Bordesley Hall,
The Holloway, Alvechurch, Birmingham, B48 7QB.
The Castings Development Centre (incorporating Steel Castings Research &
Trade Association), 7 East Bank Road, Sheffield, S2 3PT.
Chem-Trend (UK) Ltd, Bromley Street, Lye, Stourbridge, West Midlands
DY9 8HY.
Copper Development Association, Verulam Industrial Estate, 224, London
Road, St. Albans, Herts, AL1 1AQ.
Foundry International, DMG Business Media Ltd, Queensway House, 2
Queensway, Redhill, Surrey, RH1 1QS.
Foundry Management & Technology, 1100 Superior Avenue, Cleveland, OH
44114, USA.
Foundry & Technical Liaison Ltd, 6-11 Riley Street, Willenhall, West
Midlands, WV13 1RH.
The Institute of British Foundrymen, Bordesley Hall, The Holloway,
Alvechurch, Birmingham,
B48 7QA.
International Magnesium Association, 1303 Vincent Place, Suite One,
McLean, Virginia 22101, USA.
OEA (Organisation of European Aluminium Refiners and Remelters,
Broadway House, Calthorpe Road, Five Ways, Birmingham, B15 1TN.
Ramsell Furnaces Ltd, Wassage Way, Hampton Lovett Industrial Estate,
Droitwich, Worcestershire, WR9 0NX.
Striko UK Ltd, Newcastle Street, Stone, Staffordshire, ST15 8JT.
The author gratefully acknowledges the help received from many individ-
uals, in particular from colleagues at Foseco.
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.
Chapter 1
Tables and general data
SI units and their relation to other units
The International System of Units (SI System) is based on six primary
units:
Quantity Unit Symbol
length metre m
mass kilogram kg
time second s
electric current ampere A
temperature degree Kelvin K
luminous intensity candela cd
Multiples
SI prefixes are used to indicate multiples and submultiples such as 10
6
or
10
–3
Prefix Symbol Prefix Symbol
10 deca da 10
–1
deci d
10
2
hecto h 10
–2
centi c
10
3
kilo k 10
–3
milli m
10
6
mega M 10
–6
micro
10
9
giga G 10
–9
nano n
10
12
tera T 10
–12
pico p
Example: One millionth of a metre is expressed as one micrometre, 1 m.
Không có nhận xét nào:
Đăng nhận xét