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type of Casting Defect

type of casting defects In the foundry industry, casting defects can occur during the casting process, resulting in imperfect or unusable castings. These defects can be caused by a variety of factors, including design flaws, material selection, process parameters, and handling practices. Here are some common casting defects: 1. Porosity: This defect refers to the presence of small voids or cavities within the casting. It can occur due to gas entrapment during solidification or inadequate venting of the mold. 2. Shrinkage: Shrinkage defects occur when the casting volume decreases during solidification, leading to voids or shrinkage cavities. Shrinkage can happen due to improper gating or insufficient feeding of molten metal. 3. Inclusions: Inclusions are foreign materials embedded in the casting, such as sand, slag, or oxides. They can result from the contamination of molten metal or improper handling of the mold. 4. Cold shuts: Cold shuts happen when two or more streams of molten metal
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HPDC casting defects

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Types of defects in HPDC (High Pressure Die casting) In this paper we will discuss about aluminum Die casting Casting . Casting defects may be defined as characteristics which create a deficiency or imperfection to quality specification imposed by design and service requirement. Casting defects are caused by non optimized process, failure of material,casting equipment. So the defects can be tolerated and repaired. In aluminum die casting the molten aluminum is poured or injected into metallic die. There are many sources to cast defects and have many names. In this paper an attempt has been made to provide aluminum casting defects with their causes and remedies. 1. visual defect.     a.  non filling     b.  cold flows     c.  Discolored     d.   lamination 2. P orosity.     a. shrink     b. flow     c. gas 3. leakage. 4. blisters 5. sinks 6. drags 7. soldering 8. bending.  9. distortion 10. trim damage VISUAL DEFECTS This kind of defect occur beca
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HPDC DEFECTS PART2

GAS POROSITY Porosity is one of the biggest problems in die casting. High volume production and very near net shape make the process very attractive, but the reputation of die castings as having high porosity has heavily restricted use of the process. Strong customer pressure for better quality has forced an increased use of engineering and technology, which is rapidly reducing the traditional porosity problems. Currently, there are successful applications for heat treatable die castings that would not have been considered even a few years ago. Shrinkage porosity and gas porosity are the major types of internal porosity in die castings. There is another type of porosity, called flow porosity, which will be discussed later. Gas and shrinkage porosity require almost completely opposite actions for corrections, hence a person doing troubleshooting must first identify the type of porosity in question; otherwise the corrective action is likely to be of little or no value. However, even
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SMED (single Minute Exchange Die)

HOW TO REDUCE YOUR DIE LOADING TIME IN HIGH PRESSURE DIE CASTING ?? ANSWER :: THERE ARE FEW STEPS IN DIE LOADING IN HPDC 0. LAST OK SHOT 1. PREPARATION 2. MOUNTING 3. SETTING 4. FIRST OK "ON SHOT TIME BETWEEN LAST OK SHOT TO FIRST OK SHOT IS YOUR TOTAL DIE CHANGEOVER TIME. PREPARATION : There are some parallel activity and some planed activity which must be keep in mind during Die change over.   During Die unloading the Die that to be loaded must be near by machine or in crane approach area. The die that we have to load must be completely ready. such as its cooling, hydraulic cylinder leakage test, core signal , die face condition , pins condition , punch conditions and other points in Die check sheet must be check.       2. MOUNTING :By using hydraulic clamp we can reduce the time of unclamp.                          Four clamp in each side minimum. i.e depend on size of Die              Manual Unclaming Time is approximate 15 minutes for both Fix and M
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solution of these defects

Here are some solutions for common casting defects in the foundry industry: 1. Porosity:    - Use proper gating and riser design to ensure adequate flow and venting of gases.    - Use degassing agents or processes to remove gases from the molten metal.    - Increase the pouring temperature to improve fluidity and reduce gas entrapment.    - Optimize mold and core properties to minimize gas generation. 2. Shrinkage:    - Use effective risering and gating systems to provide additional molten metal for compensating shrinkage.    - Modify the mold design to promote directional solidification and minimize shrinkage tendencies.    - Increase pouring temperature and ensure proper solidification time to reduce shrinkage defects. 3. Inclusions:    - Ensure proper handling and storage of materials to prevent contamination.    - Use appropriate filtration systems to remove impurities from the molten metal.    - Implement proper slag removal techniques during the casting process. 4. Cold shuts:  
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HIGH PRESSURE DIE CASTING PARAMETER CALCULATION ALUMINUM ALLOY

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PARAMETER CALCULATION IN HPDC THERE ARE THREE PHASES IN HPDC MACHINES 1 FIRST PHASE :- Slow speed 2 SECOND PHASE :- High Speed 3 THIRD PHASE :- Intensification Pressure or Casting Pressure.                                                                                                          pouring hole Distributor Length / Active sleeve length                                 Biscuit  3rd phase     2nd phase            1st phase    Plunger/shot 1 FIRST PHASE :- Slow speed It is the distance start from plunger starting position to the distance traveled by plunger by which metal reached at cavity gate area.       2 SECOND PHASE :- High Speed It is the Distance traveled by plunger in which casting filled in cavity.In this distance plunger traveled with its high speed of the stroke. How to calculate that travelling distance of plunger that filled the alloy in cavity. velocity Distance   + Biscuit thickness mm The minimum velocity that w
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DIE FLASHING PROBLEM

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DIE FLASHING When a layer of extra metal around parting line of a parts after shots is die flashing, also during high speed shot when metal get out of die and a biscuit variation occur. TYPES OF DIE FLASHING: 1. FLASH INSIDE THE DIE FACE  2. FLASH OUT OF DIE AND FIRED IN THE AIR 3. FLASH IN SLIDES AREA 1 . FLASH INSIDE THE DIE FACE :-  This types of flash occur only within Die , when we get a parts after shots there is extra metal layer at parting lines of parts. CAUSE:            This flash is occur due to some following reasons              1. Die locking force is low for the die.              2. Cooling of inserts fix/moving.              3. Proper die face not matching. SOLUTIONS :          1. Check Die locking force           2. Check Die cooling.          3. Check die face blue matching.          4. Check Plunger high speed according to required gate speed.          5. Check load distribution on Tie bar 2. FLAS
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