Table Of Content

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 Preface The last edition of the Handbookwas 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 Handbookto 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 Handbookrefers 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 ........................................................................Preface ...............................A..c..k..n..o...w..l.e..d...g.ements 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.. .A...l.u..m...i.n..i.u...m... .c..a..s..t.i.n..g alloys ............................................................................I.n.troduction Casting alloys.......................................................................... 25 Casting processes................................................................... 39 The effect of alloying elements................................................ 39 Heat treatment of aluminium alloys......................................... 42 .......3.. .M...e..l.t.i.n..g.. .a..l.u...m...i.n..i.u..m. alloys ............................................................................I.n.troduction Raw materials.......................................................................... 47 Melting furnaces...................................................................... 47 Corundum growth.................................................................... 54 Choice of melting unit.............................................................. 55 .....................................................................4. Fluxes Applicati.o..n.. .o..f. .C...O..V...E..R...A..L.. .p..o..w..der fluxes Granular COVERAL fluxes...................................................... 61 5 INSURAL refractory for ladles and metal ...................................................................t.r.ansport Ladle liners.............................................................................. 65 6 Treatment of alu..m...i.n...i.u..m... .a..l.l.o.y melts Hydrogen ga..s.. .p..i.c.k..-.u..p.. .i.n.. .a..l.u..m...i.n.ium 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 alumini.u...m... .a..l.l.o..y.. .c.astings 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 alu..m....i.n..i.u..m. 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 g..r.a..v..i.t..y.. .d..i.e.casting ....................................L..o..w.. .p..r..e..s.s..u..r.e.. .diecasting Gravity diecasting.................................................................... 124 Die coatings for gravity and low pressure diecasting.............. 127 .....1..1.. .S...a..n..d.. .c..a..s..t.i.n...g.. .p..r.o..cesses Green sand.............................................................................. 136 Moulding machines.................................................................. 137 Core assembly sand processes.............................................. 140 The Lost Foam process........................................................... 144 12 Sands and sa.n..d.. .b..o..n...d..i.n..g.. .s.ystems Propertie.s. .o..f. .s..i.l.i.c.a.. .s..a..n..d.. .f.o..r. .f.o..undry 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 ......................1..3.. .R...e..s..i.n.. .b..o..n...d..ed sand ..................................C..h..e..m...i.c..a..l.l.y. .b..o..n.ded sand Self-hardening process (also known as self-set, no- bake ....................................o..r. .c..o..l.d..-. .s..e..t.t.i.n..g 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 Sodi.u...m... .s..i.l.i.c..a..t.e.. .b..o..n...d..ed sand ................................................................S...o..d..i.um 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 .....................1..5.. .M...a..g..n..e..s..i.u...m... casting ....................................................................C...a..s.ting alloys The melting, treatment and casting of magnesium alloys....... 218 16 Copper and c.o..p..p..e..r.. .a..l.l.o..y.. .c.astings The main copper allo..y..s. .a..n..d.. .t.h..e..i.r. .a..p.plications 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 ..............................1..7.. .F..e..e..d...i.n..g.. .s.ystems ................................................................N..a..t.u..r.al 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