what is solidworks ? SolidWorks is a popular 3D computer-aided design (CAD) software that is used for creating and designing complex models and assemblies in mechanical engineering, product design, and other industries. It is developed by Dassault Systèmes, a French software company that also owns other popular software such as CATIA and SIMULIA. SolidWorks provides a range of tools and features for creating 3D models, such as sketching, surface modeling, solid modeling, sheet metal design, and assembly modeling. It allows users to simulate and analyze the performance of their designs before manufacturing, including motion analysis, finite element analysis (FEA), and computational fluid dynamics (CFD). It also supports collaboration and sharing of designs with other users through various formats such as STEP, IGES, and STL. SolidWorks is known for its user-friendly interface and intuitive design, which makes it easy for beginners to learn and use. It is widely used in industries such a...
Metal Casting :
Casting is a process in which the liquid molt
en metal is poured into the casting cavity whose shape is same as that of the casting to be produced and allowed it to solidify .
After Solidification the casting can be taken out by breaking the mould .
Advantages of casting :
1. Any shape can be produced .
2. Any material can be cast .
3. Requiring tools are simple and inexpensive .
4. Heavy equipment can be cast easily in required size rather than fabricating them by joining several smaller pieces .
Limitations
Dimension accuracy and surface finish is poor .
Steps in casting :
1. Pattern Making
2. Mould and core making
3. Pouring and solidification
4. Fetting
5. Inspection
1. Pattern Making :
Patten is the replica of casting .
Pattern size =casting size + - allowance
Allowances :
1. Shrinkage Allowance ( SA)
2. Machining Allowance
3. Draft Allowance
4. Shake Allowance
5. Distortion Allowance / Bending Allowance
Shrinkage Allowance :
Three stage -
1. Shrinkage of molten metal when reducing from pouring temperature to freezing temperatures .
2. Shrinkage of molten metal during freezing .
3. Shrinkage solid metal when reducing from freezing temperature to room temperature .
* In casting process aluminium have highest liquid shrinkage that is 6 % .
* Gray cast - iron have a negative liquid shrinkage and solid solid shrinkage is positive .
* Total shrinkage ( solid + liquid ) will be highest in steels .
Machining Allowance :
Extra material provided on the pattern is called machining allowance .
Machining allowance is provided for good surface finish .
Draft Allowance :
Making the vertical surface of pattern .
Easy removal of pattern from mould .
Shake Allowance :
Shake allowance is provided to avoid mold damages taking place due to adhesiveness property of moulding sand .
Pattern is made by using materials like wax , mercury , polystyrene .
Distortion Allowance / Bending Allowance :
It is mainly required in casting of U or V shaped casting .
Types of Pattern :
1. Solid or single piece pattern
2. Split pattern
3. Match plate pattern
4. Gated pattern
5. Sweep pattern
6. Skeleton pattern
7. Loose piece pattern
8. Follow board pattern
9. Shell pattern
Types of pattern
Patten Materials :
1. Wood
2. Metals
3. Plastics
4. Wax
5. Mercury
Mould Making :
Three basic elements :
1. Silica sand particles ( 75- 80 %)
2. Clay ( 15 - 20 % )
3. Water or sodium silicate (6 -8%)
4. Additives ( 2% )
Additives :
1. Saw dust or wood powder :
Increasing porosity and collapsibility .
Porosity
2. Coal powder :
Increasing refractoriness .
3. Starch or dextrin :
Increasing strength , resistance .
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| Saw dust or wood powder |
 |
| Coal powder |
Starch or dextrin
Types of sands :
1. Green sand :
Silica sand + clay + water
Green Sand
2. Dry sand :
Silica sand + clay + clay + sodium silicate
Dry Sand
3. Loam sand :
Green sand or dry sand with 50 % clay .
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