Ejector Pump
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Ejector pump

Ejector Pump

The ejector pump is a type of vacuum pump. Gas is removed from a container by passing steam or water at a high velocity through a chamber that is connected to the container. The mixing chamber contains both the gas from the container and the steam or water. At the inlet port, the ejector pump is connected to the container that is being evacuated.

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  • Melting

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  • For both ferrous and non ferrous castings.(melting temperature upto 16500C)

  • Very accurate details obtained in intricate shapes

  • Excellent surface finish, machining and cleaning costs minimum.

  • Accuracy of 0.002 mm per mm obtained.

  • But, casting process costly.

  • Casting cost high.

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PRODUCTION OF ALLOY WHEELS

METHOD OF PRODUCTION; COUNTER PRESSURE DIE CASTING

The manufacturing process commences with the smelting of pure aluminium ingots in a 5-ton basin type furnace.

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The furnace is a dry sole type furnace whose function is to smelt the primary raw material, and reprocess alloy scraps consisting of:- wheels used in destructive testing by the quality control department, and the risers and gates removed from the wheels following the casting process. From the dry sole furnace, the molten aluminium is transferred to the alloy induction furnaces via a feed channel to enable the mixing and smelting of the elements required in the preparation of the alloy – AlSi 7.

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A spectrometer equipped quality control laboratory is used during the process of alloy preparation to ensure the composition of the alloy meets the required specification during this stage of the preparation process. Spectrometer analysis sampling is also applied randomly to finished wheels.

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Molten alloy is transferred to holding furnaces for eventual transfer to the casting machines. After the molten alloy has been tested for conformance to specifications, it is transported to the alloy treatment station where the alloy is submitted to three procedures performed by an automatic process control system. The treatment unit introduces salts into the molten alloy using a high-speed spinner, where the alloy purification is assisted by the use of nitrogen gas jets. The three procedures to which the molten alloy is submitted are:-

·Degassing

·Refining

·Modifying

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These processes are intrinsic to the removal of all undesirable impurities in the molten alloy. The automation of these processes improves the product quality control, production rates and importantly minimizes wastage by reducing the possibilities of rejection of the finished product. Following the procedures to ensure that the molten alloy conforms to precise specification, it is transported in holding furnaces to the low pressure casting machines. These furnaces are designed to produce casting by employing pressurised air within a range of 0.3 – 1.0 atm., the pressurization being monitored and varied by a computerized process control system according to flow requirements

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Computerized process technology automatically controls the casting process, and then, at the end of the 4.5 minute casting cycle, cools and ejects the wheel onto a catcher arm designed for this purpose.

Holding furnaces contain between 500-750kg of molten alloy - sufficient for up to approx. 4 hours of casting operations. When the holding furnace is exhausted it is exchanged for a full replacement furnace using the transfer shuttle - illustrated above - without interruption to the casting process.

Hydraulic systems control many of the unit’s operating movements, and, due to high operating temperatures many measures have to be taken to enable minimization of risk and reduction of maintenance of these systems. For example, it is necessary for all hydraulic systems to employ fire resistant fluids thereby eliminating fire risk.

Likewise, all hydraulic hoses have to be metal covered and insulated against accidental splashes of molten metal.

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The operators of the Counter Pressure Casting Machines perform an initial visual quality control as the wheels are ejected from each unit and palleted ready for transport to the Riser cutting department.

At this first stage in the machining process following casting, the removal of the gates and risers is carried out by automated machines designed for this purpose – with a cycle time of 50 seconds per wheel. The CNC riser-cutting unit performs the following operations

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·      Pre-boring of the central hole of the wheel

·         Removal of the channel burrs corresponding to the surface joints on the Die’s moving parts

·         Trimming upper and lower edges of the wheel

The working cycle of the Riser cutting unit is completely automated to improve both quality control and production rate per machine. All waste products are collected for recycling at the foundry. The machine operations are performed under a suction hood to remove aluminium dust and particulates from the environment in proximity to this unit.

Customarily, after the machining processes have been completed on the newly cast wheels, the wheels are passed to the quality control unit for examination under a variety of non-destructive and destructive tests. Batch sampling of the wheels may involve taking a 1-2mm scrape taken using a lathe, and running a spectrometer analysis of the resulting alloy sample.

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X-Ray analysis machine in Quality control department

Non-destructive testing is undertaken using radiography processes. It is common practice for the VM customers to include within their contractual requirements testing volumes and timescales (i.e. before or after machining). The X-ray control equipment can be pre-set with information from up to 1000 wheel designs, and wheels can be inspected on a wide variety of positions / angles (normally 20 position variants).

The wheel manipulator for handling the wheels during the inspection cycle has 5 fully computerized axes and a roller conveyor automatically provides loading/unloading of the machine with the wheels for inspection.

The X-Ray unit takes 2 wheels at a time - one in process of inspection cycle, and a second wheel in a ‘holding’ position. As the testing machine completes the automated inspection cycle, it simultaneously ejects the inspected wheel, puts the second wheel into position for inspection and draws another wheel into the ‘holding’ position. Thus the performance inspection cycle is enhanced to its maximum possibility. During an inspection, the operator monitors the x-ray image on a viewing console and has the possibility of magnifying the image or ‘replaying’ the process to precisely identify any casting defect exposed by this machine.

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The next stage of the quality control process is undertaken on Geometrical control benches where the physical dimensions of the wheels are compared with the specification standard using pantographs and micrometers.

The semi- finished product, having been submitted to various machining and quality control procedures are passed to the finishing dept. which - dependent upon client specification - either submits the wheels through an automated paint shop - or polishing line where a bright lacquer finish has been specified.

The finished wheels are then palleted and wrapped in polyethylene film - ready for transfer to a wheel/tyre assembly plant - prior to final shipment to the production lines of the VM customer

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The pallet/box wrapping equipment consists of a motorized wrapping machine – allowing pallets to beplaced on a rotating turntable, and providing film wrapping through this rotation with a fixed unit holding the polyethylene roll.

The finished wheels are stored on pallets/boxes until shipping.  

COUNTER PRESSURE DIE CASTING MACHINES

The casting machines have evolved over 25 years of development and manufacturing experience of counter-pressure & low pressure casting machines.

Simplicity of design, operating convenience and ease of maintenance are the core attributes that produce highest levels of egonomics and safety.

The above principles are well emphasised by the rugged vertical tie-bar construction incorporating an integral holding furnace.

The well tried and proven technical solutions provide stability, accuracy in guiding and controlling the precision of the moving parts, and include essential rigidity, operational dependability and longevity of the machines.

All machines are designed to withstand heavy-duty service in foundries operating continuous 24 hour cycles.

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Inspection of castings

INSPECTION OF CASTINGS

  • SEVERAL METHODS

  • VISUAL

  • OPTICAL

  • - FOR SURFACE DEFECTS

  • SUBSURFACE AND INTERNAL DEFECTS THROUGH NDTs & DTs

  • PRESSURE TIGHTNESS OF VALVES BY SEALING THE OPENING AND PRESSURISING WITH WATER

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Casting defects

SURFACE

METALLIC PROJECTION (4)

DEFECTIVE SURFACE (11)

CHANGE IN DIMENSION- WARP

INCOMPLETE CASTING

MISRUN, RUNOUT

CAVITY-

BLOWHOLES, SHRINKAGE

PINHOLES

DISCONTINUITY

HOT CRACK

COLD SHUT, COLD CRACK

SUBSURFACE

SUBSURFACE CAVITY

INCLUSIONS

DISCONTINUITY

CASTING DEFECTS

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NDTs

Methods of testing

Destructive-

Non destructive-

Radiagraphic

Ultrasonic

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Non Destructive Testing

with Ultrasonics

for flaw Detection in Castings,

Weldments, Rails, Forged Components etc.

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Ultrasonic testing

ULTRASONIC TESTING

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Why ultrasonics

Why Ultrasonics ?

………

Flaw detection in metals and nonmetals

Flaw measurement in very thick materials

Internal and surface flaws can be detected

Inspection costs are relatively low.

Rapid testing capabilities and portability.

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Ultrasonic waves are simply vibrational waves having a frequency higher than the hearing range of the normal human ear, which is typically considered to be 20,000 cycles per second (Hz).

The upper end of the range is not well defined. Frequencies higher than 10 GHz have been generated. However, most practical ultrasonic flaw detection is accomplished with frequencies from 200 kHz to 20 MHz, with 50 MHz used in material property investigations. Ultrasonic energy can be used in materials and structures for flaw detection and material property determinations.

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  • Ultrasonic waves are mechanical waves (in contrast to, for example, light or x-rays, which are electromagnetic waves) that consist of oscillations or vibrations of the atomic or molecular particles of a substance about the equilibrium positions of these particles. Ultrasonic waves behave essentially the same as audible sound waves. They can propagate in an elastic medium, which can be solid, liquid, or gaseous, but not in a vacuum.

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In solids, the particles can (a) oscillate along the direction of sound propagation as longitudinal waves, or (b) the oscillations can be perpendicular to the direction of sound waves as transverse waves.   At surfaces and interfaces, various types of elliptical or complex vibrations of the particles occur.

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Theory of testing

THEORYOF TESTING

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Machine specifications

MACHINE SPECIFICATIONS

Make:

Weight:

Calibration range upto 9999 mm.

Choice of Frequency range

Provision for adjusting gain.

Documentation possibility via printer

Limitation:…………….

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Probe

Probe

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Scanning techniques

SCANNING TECHNIQUES

  • Pulse Echo method

  • Straight beam method

  • Angle beam method

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Pulse echo method

PULSE ECHO METHOD

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Inspection of

Inspection of:

  • Gas porosity

  • Slag Entrapment

  • Cracks

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With the exception of single gas pores all the defects listed are usually well detectable by ultrasonics.    

Ultrasonic flaw detection has long been the preferred method for nondestructive testing , mainly in welding applications.  

This safe, accurate and simple technique has pushed ultrasonics to the forefront of inspection technology.

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The proper scanning area for the weld:

First calculate the location of the sound beam in the test material.  

Using the refracted angle, beam index point and material thickness, the V-path and skip distance of the sound beam is found.

Then identify the transducer locations on the surface of the material corresponding to the crown, sidewall, and root of the weld.

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Inspection of rails

Inspection of Rails

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  • New trend:

    Ultrasonic Simulation - UTSIM

    UTSIM is a user interface integrating a CAD model representing a part under inspection and an ultrasound beam model.

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Ultrasonic sizing of small flaws with

the distance-amplitude-correction (dac) curve

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Casting defects1

Casting Defects

  • Metal casters try to produce perfect castings.

  • A few castings, however, are completely free of defects.

  • Modern foundries have sophisticated inspection equipment which can detect small differences in size and a wide variety of external and even internal defects. For example, slight shrinkage on the back of a decorative wall plaque is acceptable whereas similar shrinkage on a position cannot be tolerated.

  • No matter what the intended use, however, the goal of modern foundries is zero defects in all castings


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  • Scrap castings cause much concern.

  • In industry, scrap results in smaller profits for the company and ultimately affects individual wages.

  • Scrap meetings are held daily. Managers of all the major departments attend these meetings. They gather castings that have been identified as scrap by inspector. The defect is circled with chalk. An effort is made to analyze the cause of the defect, and the manager whose department was responsible for it is directed to take corrective action to eliminate that specific defect in future castings.

  • There are so many variables in the production of a metal casting that the cause is often a combination of several factors rather than a single one.

  • All pertinent data related to the production of the casting (sand and core properties, pouring temperature) must be known in order to identify the defect correctly.

  • After the defect is identified attempt should be to eliminate the defect by taking appropriate corrective action.


Casting defects2

SURFACE

METALLIC PROJECTION –

Swell, Crush, Mould Drop, Fillet Vein

DEFECTIVE SURFACE –

Erosion Scab, Fusion, Expansion Scab, Rat tails, Buckle, Seams, Gas Runs, Fillet Scab, Rough Surface, Slag Inclusion, Elephant Skin

CHANGE IN DIMENSION-

Warped casting

INCOMPLETE CASTING-

Misrun, Run out

CAVITY-

Blow Holes, Shrinkage cavity, Pinholes

DISCONTINUITY-

Hot6 Cracking, Cold Shut, Cold Cracking

SUBSURFACE

SUBSURFACE CAVITY-

Blow Holes, Pin Holes, Shrinkage

Porosity, Internal Shrinkage, Severe

Roughness

INCLUSIONS-

Gas Inclusions, Slag, Blow Holes

DISCONTINUITY-

Cold Shuts

CASTING DEFECTS

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Repairability


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FINS OR FLASH ON CASTINGS -AsMetallic Projections

  • Joint flash or fins. Flat projection of irregular thickness, often with lacy edges, perpendicular to one of the faces of the casting. It occurs along the joint or parting line of the mold, at a core print, or wherever two elements of the mold intersect.

  • Possible Causes

  • Clearance between two elements of the mold or between mold and core;

  • Poorly fit mold joint.

  • Remedies

  • Care in pattern making, molding and core making;

  • Control of their dimensions;

  • Care in core setting and mold assembly;

  • Sealing of joints where possible.


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  • Flask was disturbed while investment was setting.

  • Base was removed too soon.

  • Flask was allowed to partially dry before dewaxing.

  • Incorrect dewaxing or a furnace malfunction.

  • Flask burned out and allowed to cool below (500oF (260oC) before casting reheating, flask allowed to cool between dewax and placement in preheated oven.

  • Flask was improperly handled or dropped.

  • Speed was set too high on centrifugal casting machine.

  • Patterns were placed on one plane. The should be staggered on top rack.

  • Incorrect water powder ratio was used.

  • Not enough investment was placed over the patterns.

  • Flask was placed too close to heat source in burnout oven.

  • Flasks were not held at low burnout temperature long enough.


Defects in castings can be eliminated minimised by proper design mold preparation proper pouring

DEFECTS IN CASTINGS- CAN BE ELIMINATED/MINIMISED BY PROPER DESIGN, MOLD PREPARATION, PROPER POURING.

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Defects in castings as hot tears due to constraints in locations castings cannot shrink freely

DEFECTS IN CASTINGS- AS HOT TEARS - DUE TO CONSTRAINTS IN LOCATIONS, CASTINGS CANNOT SHRINK FREELY

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Cavities

  • Blowholes, pinholes. Smooth-walled cavities, essentially spherical, often not contacting the external casting surface (blowholes). The largest cavities are most often isolated; the smallest (pinholes) appear in groups of varying dimensions.

  • The interior walls of blowholes and pinholes can be shiny, more or less oxidized or, in the case of cast iron, can be covered with a thin layer of graphite. The defect can appear in all regions of the casting.


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  • Possible Causes

  • Because of gas entrapped in the metal during the course of solidification:

  • Excessive gas content in metal bath (charge materials, melting method, atmosphere, etc.); Dissolved gases are released during solidification.

  • In steel and cast irons: formation of carbon monoxide by the reaction of carbon and oxygen, presents as a gas or in oxide form. Blowholes from carbon monoxide may increase in size by diffusion of hydrogen or, less often, nitrogen.

  • Excessive moisture in molds or cores.

  • Core binders which liberate large amounts of gas.

  • Excessive amounts of additives containing hydrocarbons.

  • Blacking and washes which tend to liberate too much gas.

  • Insufficient evacuation of air and gas from the mold cavity; -insufficient mold and core permeability.

  • Entrainment of air due to turbulence in the runner system.


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  • Remedies

  • Make adequate provision for evacuation of air and gas from the mold cavity

  • Increase permeability of mold and cores

  • Avoid improper gating systems

  • Assure adequate baking of dry sand molds

  • Control moisture levels in green sand molding

  • Reduce amounts of binders and additives used or change to other types; -use blackings and washes, which provide a reducing atmosphere; -keep the spree filled and reduce pouring height

  • Increase static pressure by enlarging runner height.


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Discontinuities

  • Hot cracking. A crack often scarcely visible because the casting in general has not separated into fragments. The fracture surfaces may be discolored because of oxidation. The design of the casting is such that the crack would not be expected to result from constraints during cooling.

  • Possible Causes

  • Damage to the casting while hot due to rough handling or excessive temperature at shakeout.

  • Remedies

  • Care in shakeout and in handling the casting while it is still hot;

  • Sufficient cooling of the casting in the mold;

  • For metallic molds; delay knockout, assure mold alignment, use ejector pins


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Defective Surface

  • Flow marks. On the surfaces of otherwise sound castings, the defect appears as lines which trace the flow of the streams of liquid metal.

  • Possible Causes

  • Oxide films which lodge at the surface, partially marking the paths of metal flow through the mold.

  • Remedies

  • Increase mold temperature;

  • Lower the pouring temperature;

  • Modify gate size and location (for permanent molding by gravity or low pressure);

  • Tilt the mold during pouring;

  • In die casting: vapor blast or sand blast mold surfaces which are perpendicular, or nearly perpendicular, to the mold parting line.


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Incomplete Casting

  • Poured short. The upper portion of the casting is missing. The edges adjacent to the missing section are slightly rounded, all other contours conform to the pattern. The spree, risers and lateral vents are filled only to the same height above the parting line, as is the casting (contrary to what is observed in the case of defect).

  • Possible Causes

  • Insufficient quantity of liquid metal in the ladle;

  • Premature interruption of pouring due to workman’s error.

  • Remedies

  • Have sufficient metal in the ladle to fill the mold;

  • Check the gating system;

  • Instruct pouring crew and supervise pouring practice.


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Incorrect Dimensions or Shape

  • Distorted casting. Inadequate thickness, extending over large areas of the cope or drag surfaces at the time the mold is rammed.

  • Possible Causes

  • Rigidity of the pattern or pattern plate is not sufficient to withstand the ramming pressure applied to the sand. The result is an elastic deformation of the pattern and a corresponding, permanent deformation of the mold cavity. In diagnosing the condition, the compare the surfaces of the pattern with those of the mold itself.

  • Remedy

  • Assure adequate rigidity of patterns and pattern plates, especially when squeeze pressures are being increased.


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Inclusions or Structural Anomalies

  • Metallic Inclusions. Metallic or intermetallic inclusions of various sizes which are distinctly different in structure and color from the base material, and most especially different in properties. These defects most often appear after machining.

  • Possible Causes

  • Combinations formed as intermetallics between the melt and metallic impurities (foreign impurities);

  • Charge materials or alloy additions which have not completely dissolved in the melt;

  • Exposed core wires or rods;

  • During solidification, insoluble intermetallic compounds form and segregate, concentrating in the residual liquid.

  • Remedies

  • Assure that charge materials are clean; eliminate foreign metals;

  • Use small pieces of alloying material and master alloys in making up the charge;

  • Be sure that the bath is hot enough when making the additions;

  • Do not make addition too near to the time of pouring;

  • For nonferrous alloys, protect cast iron crucibles with a suitable wash coating


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  • INCLUSIONS (FOREIGN PARTICLES) IN CASTINGS

  • Patterns were improperly sprued to wax base or tree or not filleted, causing investment to break at sharp corners during casting.

  • Flask was not sufficiently cured before placing into burnout oven.

  • Improper dewaxing cycle was used.

  • Flask was not cleaned from prior cast.

  • Loose investment in sprue hole.

  • Molten metal contains excess flux or foreign oxides.

  • Crucible disintegrating or poorly fluxed.

  • Improperly dried graphite crucible.

  • Investment was not mixed properly or long enough.

  • Contaminants in wax pattern.

  • Flask was not held at low burnout temperature long enough.

  • Flask was placed too close to heat source in burnout oven.


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  • POROSITY

  • Pattern is improperly sprued.  Sprues may be too thin, too long or not attached in the proper location, causing shrinkage porosity.

  • Not enough metal reservoir to eliminate shrinkage porosity.

  • Metal contains gas.

  • Mold is too hot.

  • Too much moisture in the flux.

  • Too much remelt being used.  Always use at least 50% new metal.

  • Metal is overheated.

  • Poor mold burnout.


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  • ROUGH CASTINGS

  • A poor quality pattern

  • Flask was not sufficiently cured before placing into burnout oven.

  • Flask was held in steam dewax too long.

  • Metal, flask or both were too hot.

  • Patterns were improperly sprued.

  • Flask was placed too close to heat source in burnout oven.


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  • BUBBLES OR NODULES ON CASTINGS

  • Vacuum pump is leaking air.

  • Vacuum pump has water in the oil.

  • Vacuum pump is low on oil.

  • Investment not mixed properly or long enough.

  • Invested flasks were not vibrated during vacuum cycle.

  • Vacuum extended past working time.


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  • SPALLING (an area of the mold wall flakes into the mold cavity)

  • Flask was placed into a furnace at low temperature (below 150oC) for an extended period.

  • Flask was placed too close to the source of heat.

  • Sharp corners are struck by metal at high centrifugal velocities.

  • Improper burnout cycle was used.


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  • NON-FILL OR INCOMPLETE CASTINGS

  • Metal was too cold when cast.

  • Mold was too cold when cast.

  • The burnout was not complete.

  • Pattern was improperly sprued, creating turbulence when casting in a centrifugal casting machine.

  • Centrifugal casting machine had too high revolution per minute.


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  • GROWTH-LIKE ROUGH CASTING THAT RESISTS REMOVAL IN PICKLING SOLUTION

  • Burnout temperature too high.

  • Mold temperature was too high when casting.

  • Metal temperature was too high when casting.


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  • SHINY CASTINGS

  • Carbon residue was left in the mold, creating a reducing condition on the surface.


Average surface roughness values by various processes

AVERAGE SURFACE ROUGHNESS VALUES BY VARIOUS PROCESSES

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Design considerations

CAREFUL CONTROL OF LARGE NUMBER OF VARIABLES NEEDED-

CHARACTERISTICS OF METALS & ALLOYS CAST

METHOD OF CASTING

MOULD AND DIE MATERIALS

MOULD DESIGN

PROCESS PARAMETERS- POURING, TEMPERATURE,

GATING SYSTEM

RATE OF COOLING Etc.Etc.

DESIGN CONSIDERATIONS

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Poor casting practices, lack of control of process variables- DEFECTIVE CASTINGS

TO AVOID DEFECTS-

Basic economic factors relevant to casting operations to be studied.

General guidelines applied for all types of castings to be studied.

DESIGN CONSIDERATIONS

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Corners angles and section thickness

Sharp corners, angles, fillets to be avoided

Cause cracking and tearing during solidification

Fillet radii selection to ensure proper liquid metal flow- 3mm to 25 mm.

Too large- volume large & rate of cooling less

Location with largest circle inscribed critical.

Cooling rate less

shrinkage cavities & porosities result-

Called HOT SPOTS

CORNERS, ANGLES AND SECTION THICKNESS

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DESIGN MODIFICATIONS TO AVOID DEFECTS-

AVOID SHARP CORNERS

MAINTAIN UNIFORM CROSS SECTIONS

AVOID SHRINKAGE CAVITIES

USE CHILLS TO INCREASE THE RATE OF COOLING

STAGGER INTERSECTING REGIONS FOR

UNIFORM CROSS SECTIONS

REDESIGN BY MAKING PARTING LINE STRAIGHT

AVOID THE USE OF CORES, IF POSSIBLE

MAINTAIN SECTION THICKNESS UNIFORMITY

BY REDESIGNING (in die cast products)

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LARGE FLAT AREAS TO BE AVOIDED- WARPING DUE TO TEMPERATURE GRADIENTS

ALLOWANCES FOR SHRINKAGE TO BE PROVIDED

PARTING LINE TO BE ALONG A FLAT PLANE-

GOOD AT CORNERS OR EDGES OF CASTING

DRAFT TO BE PROVIDED

PERMISSIBLE TOLERANCES TO BE USED

MACHINING ALLOWANCES TO BE MADE

RESIDUAL STRESSES TO BE AVOIDED

ALL THESE FOR EXPENDABLE MOULD CASTINGS.

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Design modifications to avoid defects avoid sharp corners to reduce stress concentrations

DESIGN MODIFICATIONS TO AVOID DEFECTS- AVOID SHARP CORNERS TO REDUCE STRESS CONCENTRATIONS

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DESIGN MODIFICATIONS TO AVOID DEFECTS- MAINTAIN UNIFORM CROSS SECTIONS TO AVOID HOT SPOTS AND SHRINKAGE CAVITIES

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Design modifications to avoid defects good design practice

DESIGN MODIFICATIONS TO AVOID DEFECTS- GOOD DESIGN PRACTICE

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Design modifications to avoid defects staggering of intersecting regions

DESIGN MODIFICATIONS TO AVOID DEFECTS- STAGGERING OF INTERSECTING REGIONS

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Design modifications to avoid defects section thickness uniformity maintained throughout part

DESIGN MODIFICATIONS TO AVOID DEFECTS- SECTION THICKNESS UNIFORMITY MAINTAINED THROUGHOUT PART

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Design modifications to avoid defects

DESIGN MODIFICATIONS TO AVOID DEFECTS

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Design modifications to avoid defects use of metal padding chills to increase rate of cooling

DESIGN MODIFICATIONS TO AVOID DEFECTS- USE OF METAL PADDING (CHILLS) TO INCREASE RATE OF COOLING

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Design modifications to avoid defects making parting line straight

DESIGN MODIFICATIONS TO AVOID DEFECTS- MAKING PARTING LINE STRAIGHT

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Design modifications to avoid defects in design

DESIGN MODIFICATIONS TO AVOID DEFECTS-IN DESIGN

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Inspection of castings1

INSPECTION OF CASTINGS

  • SEVERAL METHODS

  • VISUAL

  • OPTICAL

  • - FOR SURFACE DEFECTS

  • SUBSURFACE AND INTERNAL DEFECTS

    THROUGH NDTs & DTs

  • PRESSURE TIGHTNESS OF VALVES BY SEALING THE OPENING AND PRESSURISING WITH WATER


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EXERCISE


Process flow chart

RECEIPT OF ORDER

(REVIEW)

ARE THE TERMS ACCEPTED? NO COMMUNICATE- NEGOTIATE

YES

PREPARE WORK ORDER

WORK ORDER TO Q.C, INSPECTION, PLANNING, METHODS, PRODUCTION AND DESPATCH

PROCESS FLOW CHART


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PRODUCTION PLAN

METHOD DRAWING, QA DATA, PATTERN PLAN

MOULDING

WORK ORDER, CORE MAKING, HEAT CONFORMATION

MELTING AND POURING

FOR THESE, LAB TEST REPORTS

KNOCK OUT

STAGE ISPECTION- NOT OK, REJECT

OK, SHOT BLASTING, GAS CUTTING/ARC CUTTING

ASTM STANDARDS

HEAT TREATMENT

ROUGH FETTLING, FINISH FETTLING,

INSPECTION


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  • NDT- CUSTOMER REPORT, NOT OK, WELDING & RECTIFICATION

  • WELDING LOG SHEET

    RE-INSPECTION, NOT OK- REJECT

  • MACHINE - IF REQUIRED

  • STRESS RELIEF

  • HYDRAULIC TESTS Etc.

  • TEST CERTIFICATE DESPATCH DOCUMENTS, PACKING, Etc. Etc.


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