Metal Casting

Metal Casting

Outline

bull 1048707 Introductionbull 1048707 Process Constraintsbull 1048707 Green Sand Castingbull 1048707 Other Processes

Some Facts

bull 1048707 Pertama pengecoran 5000-3000 SM1048707 Perunggu usia besi usia logam ringan1048707 Multifungsibull Banyak jenis logambull Cepat Produksibull Berbagai bentuk dan ukuranbull Kompleks bagian sebagai suatu unit integral

bull 1048707 First casting 5000-3000 BCbull 1048707 Bronze iron age light metal agebull 1048707 Versatilitybull bull Many types of metalsbull bull Rapid productionbull bull Wide range of shapes and sizesbull bull Complex parts as an integral unit

Example ndash Sand Casting

Example ndash Die Casting

Example ndash Investment Casting

Casting Process Physics andConstraints

bull 1048707 Fase Perubahanbull Kepadatanbull Kelarutanbull Difusi tingkat1048707 suhu tinggi lelehbull Kimia Kegiatanbull panas laten Tinggibull Penanganan

bull 1048707 Phase Changebull bull Densitybull bull Solubilitybull bull Diffusion ratesbull 1048707 High melting temperaturebull bull Chemical activitybull bull High latent heatbull bull Handling

Analysis of Casting Processes

bull 1048707 Cairan mekanik untuk cetakan mengisi1048707 Perpindahan panas untuk solidifikasi1048707 Termodinamika perpindahan massa dan panastransfer untuk nukleasi dan pertumbuhan1048707 Bahan perilaku untuk struktur-propertihubungan

bull 1048707 Fluid mechanics for mold fillingbull 1048707 Heat transfer for solidificationbull 1048707 Thermodynamics mass transfer and heatbull transfer for nucleation and growthbull 1048707 Materials behavior for structure-propertybull relationships

Mold Filling

bull 1048707 Bernoullirsquos equation

bull 1048707 Reynoldrsquos numberbull bull Turbulencebull bull Injection Molding

Re ~ 10-

Cooling for Sand Mold

Conductivity Diffusivity

bull Conductivity (WmK)bull Cu ~ 400 Al ~ 200bull Sand ~ 05 PMMAbull Sand Castingbull αsand lt αmetalbull 1048707 Die Castingbull αtool metal gt αpolymerbull 1048707 Injection Moldingbull αtool metal ~ αmetal

Solidification Time Sand Casting

bull Transient 1-D heat transfer

bull Solidification time

Solidification Time Die Casting

bull Transient 1-D heat transfer

bull Solutionbull 1048707 Solidification time

ComparisonSand Mold vs Metal Mold

bull Sand Moldbull Sand castingbull ts ~ (VA)2bull Metal Moldbull Die castingbull ts ~ (VA)1

Microstructure Formation

bull Skema ilustrasi dari tiga jenis dasar struktur cor(a) dendritik Columnar (b) dendritik sama-sumbu (c) sama-sumbu nondendritic

bull Schematic illustration of three basic types of cast structuresbull (a) Columnar dendritic (b) equiaxed dendritic (c) equiaxed nondendritic

Formation of Dendrites

Constitutional Supercooling

Green Sand Casting

Green Sand Mold

bull Dimensi Thermal dan Stabilitas kimia pada T tinggi1048707 Ukuran dan bentuk1048707 keterbasahan oleh logam cair1048707 Kompatibilitas dengan sistem pengikat1048707 Ketersediaan dan konsistensi

bull Dimensional Thermal and Chemical stability at high Tbull 1048707 Size and shapebull 1048707 Wettability by molten metalbull 1048707 Compatibility with binder systembull 1048707 Availability and consistency

Pattern Design Considerations(DFM)

bull Shrinkage allowancebull 1048707 Machining allowancebull 1048707 Distortion allowancebull 1048707 Parting linebull 1048707 Draft angle

Typical Shrinkage Allowance

bull Metal or alloy Shrinkage allowancesbull mm mbull Aluminum alloy helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 13bull Aluminum bronze helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 21bull Yellow brass (thick sections) helliphelliphelliphelliphelliphellip 13bull Yellow brass (thin sections) helliphelliphelliphelliphelliphellip 13bull Gray cast iron (a) helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 8 - 13bull White cast iron helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 21bull Tin bronze helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 16bull Gun metal helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 11 - 16bull Lead helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 26bull Magnesium helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 21bull Magnesium alloys (25) helliphelliphelliphelliphelliphelliphelliphelliphellip 16bull Manganese bronze helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 21bull Copper-nickel helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 21bull Nickel helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 21bull Phosphor bronze helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 11 - 16bull Carbon steel helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 16 - 21bull Chromium steel helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 21bull Manganese steel helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 26bull Tin helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 21bull Zinc helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 26

Typical Pattern MachiningAllowance

bull Allowances mmbull Pattern size mm Bore Surface Cope sidebull For cast ironsbull Up to 152helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 32 24 48bull 152 - 305helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 32 32 64bull 305 - 510helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 48 40 64bull 510 - 915helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 64 48 64bull 915 - 1524helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 79 48 79bull For cast steelsbull Up to 152helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 32 32 64bull 152 - 305helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 64 48 64bull 305 - 510helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 64 64 79bull 510 - 915helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 71 64 96bull 915 - 1524helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 79 64 127bull For nonferrous alloysbull Up to 76helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 16 16 16bull 76 - 152helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 24 16 24bull 152 - 305helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 24 16 32bull 305 - 510helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 32 24 32bull 510 - 915helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 32 32 40bull 915 - 1524helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 40 32 48

Gating SystemSprue Runner and Gate

bull Rapid mold fillingbull 1048707 Minimizing turbulencebull 1048707 Avoiding erosionbull 1048707 Removing inclusionsbull 1048707 Controlled flow and thermal conditionsbull 1048707 Minimizing scrap and secondarybull operations

Riser Location and Size

bull Casting shrinkagebull 1048707 Directional solidificationbull 1048707 Scrap and secondary operation

Progressive Solidification inRiser

Draft in Pattern

Investment Casting

Investment Casting (cont)

Advantages of Investment Casting

bull 1048707 Intricate geometrybull 1048707 Close dimensional tolerancebull 1048707 Superior surface finishbull 1048707 High-melting point alloys

Die Casting

Advantages of Die Casting

bull High production ratesbull 1048707 Closer dimensional tolerancesbull 1048707 Superior surface finishbull 1048707 Improved mechanical properties

Lost Foam Casting

Lost Foam Casting

bull Receive raw polystyrene beadsbull Expand beadsbull Mold component patternbull including gating systembull Join patters (if multipiece)bull Coat pattern assemblybull Dry assemblybull Invest assembly in flaskbull with backlip mediu bull Vibrate to compact mediumbull Pourbull Shakeout castingsbull Clean castings assemblybull Inspect castingsbull Ship castings

Advantages of Lost Foam Casting

bull Tidak ada garis perpisahan1048707 Tidak ada core1048707 Satu-sepotong labu1048707 Kebebasan desain1048707 Minimum penanganan pasir1048707 Kemudahan membersihkan dan sekunderoperasi

bull No parting linebull 1048707 No coresbull 1048707 One-piece flaskbull 1048707 Freedom of designbull 1048707 Minimum handling of sandbull 1048707 Ease of cleaning and secondarybull operation

Semi-solid Casting

Advantages of Semi-solid Casting

Cost - Casting

bull pengecoran pasir1048707 Tooling dan peralatan biaya rendah1048707 biaya tenaga kerja langsung yang tinggi1048707 pemanfaatan Bahan rendah1048707 biaya Finishing bisa tinggi1048707 Investasi pengecoran1048707 biaya Tooling yang moderat tergantung pada kompleksitas1048707 Biaya Peralatan rendah1048707 biaya tenaga kerja langsung yang tinggi1048707 Biaya Bahan rendah1048707 Die casting1048707 Tooling dan peralatan biaya tinggi1048707 biaya tenaga kerja langsung yang rendah sampai sedang1048707 pemanfaatan Bahan tinggi

bull Sand castingbull 1048707 Tooling and equipment costs are lowbull 1048707 Direct labor costs are highbull 1048707 Material utilization is lowbull 1048707 Finishing costs can be highbull 1048707 Investment castingbull 1048707 Tooling costs are moderate depending on the complexitybull 1048707 Equipment costs are lowbull 1048707 Direct labor costs are highbull 1048707 Material costs are lowbull 1048707 Die castingbull 1048707 Tooling and equipment costs are highbull 1048707 Direct labor costs are low to moderatebull 1048707 Material utilization is high

Quality - Casting

bull pengecoran pasir1048707 Toleransi (07 ~ 2 mm) dan cacat dipengaruhi oleh penyusutan1048707 properti Material secara inheren buruk1048707 Umumnya memiliki permukaan kasar kasar1048707 Investasi pengecoran1048707 Toleransi (008 ~ 02 mm)1048707 properti Mekanikal dan mikro tergantung pada metode1048707 Baik untuk detail permukaan yang sangat baik mungkin karena bubur halus1048707 Die casting1048707 Toleransi (002 ~ 06 mm)1048707 sifat mekanik yang baik dan mikro karena tingginyatekanan1048707 detil Luar permukaan

bull Sand castingbull 1048707 Tolerance (07~2 mm) and defects are affected by shrinkagebull 1048707 Material property is inherently poorbull 1048707 Generally have a rough grainy surfacebull 1048707 Investment castingbull 1048707 Tolerance (008~02 mm)bull 1048707 Mechanical property and microstructure depends on the methodbull 1048707 Good to excellent surface detail possible due to fine slurrybull 1048707 Die castingbull 1048707 Tolerance (002~06 mm)bull 1048707 Good mechanical property and microstructure due to highbull pressurebull 1048707 Excellent surface detail

Rate - Casting

bull pengecoran pasir1048707 Waktu Pembangunan adalah 2 ~ 10 minggu1048707 Tingkat Produksi tergantung pada waktu pendinginan t ~ (V A) 21048707 Investasi pengecoran1048707 Waktu Pembangunan adalah 5 ~ 16 minggu tergantung pada kompleksitas1048707 Tingkat Produksi tergantung pada waktu pendinginan t ~ (V A) 21048707 Die casting1048707 Waktu Pembangunan adalah 12 ~ 20 minggu1048707 Tingkat Produksi tergantung pada waktu pendinginan t ~ (V A) 1

bull Sand castingbull 1048707 Development time is 2~10 weeksbull 1048707 Production rate is depending on the cooling time t~(VA)2bull 1048707 Investment castingbull 1048707 Development time is 5~16 weeks depending on the complexitybull 1048707 Production rate is depending on the cooling time t~(VA)2bull 1048707 Die castingbull 1048707 Development time is 12~20 weeksbull 1048707 Production rate is depending on the cooling time t~(VA)1

Flexibility - Casting

bull pengecoran pasir1048707 tinggi tingkat kompleksitas bentuk (dibatasi oleh pola)1048707 Investasi pengecoran1048707 Keramik dan inti lilin memungkinkan kompleks internal yangkonfigurasi tetapi biaya meningkat secara signifikan1048707 Die castingKarena biaya modifikasi die tinggi rendah 1048707

bull Sand castingbull 1048707 High degree of shape complexity (limited by pattern)bull 1048707 Investment castingbull 1048707 Ceramic and wax cores allow complex internalbull configuration but costs increase significantlybull 1048707Die castingbull 1048707 Low due to high die modification costs

New Developments in Casting

bull Computer-aided designbull 1048707 Rapid (free-form) pattern making