Halloween Costume ideas 2015

Knowledge Is Free

April 2014

Pressure 
Casting Operation Is Ready To Begin

Pressure casting is the types of permanent mold casting processes in which air pressure is used to move the molten metal into the mold. Unlike other casting processes in which metal flow from top to bottom in pressure casting molten metal moves from bottom to the top.



Parts of pressure casting machine


  • Air tight camber
  • Inlet valve
  • Container for molten metal
  • Refractory tube
  • Mold
  • Mold moving mechanism




Steps involves in pressure casting

Step 1

Two parts of the mold are prepared and machined with extreme accurately, so they can open and close precisely for removal of metal parts. Unlike other molds, mold of pressure casting have the gating system which support the flow of metal from bottom to the top. Mold is then placed over the air tight sealed chamber having the molten metal in it

Step 2

After that air is introduce into the chamber through the air inlet valve. After some time chamber is completely filled with air and after that when more air is introduce into the chamber it will create pressure on the molten metal.



Pressure 
On Surface Of Molten Material

Step 3

Air pressure on the molten metal will force it to move up into the mold through the refractory tube. Air pressure will be maintained until the molten metal in the mold solidifies.



Molten 
Material Forced Up Refractory Tube


Pressure 
Applied During Solidification


Step 4

After the metal solidifies pressure is removed and mold is open to remove the cast part



Advantages of pressure casting


  • Good mechanical properties 
  • Good dimensional accuracy
  • Good surface finish
  • Good for mass production
  • Less oxidation effect


Disadvantages of pressure casting


  • High set up cost
  • Not suitable for small production
  • Geometry of the part is limited






Vacuum molding is the process used in both types of the casting that is permanent mold and expandable mold casting. We have already written about the vacuum molding process of expandable mold type and now we will learn about vacuum molding of permanent mold type. In permanent mold vacuum casting molten metal is forced into the casting cavity through the gating system.


Steps involves in vacuum molding

Step 1

An especially design mold cavity is made for this process. Having the gating system at the bottom and casting cavity at the top. Molten metal will rise from bottom to the top

Permanent 
Mold For Vacuum Casting

Step 2

Mold cavity is place over the tank having the molten metal

Vacuum 
Mold Over Supply Of Molten Metal

Step 3

Vacuum is applied at the top of the mold and molten metal is sucked up through the gating system and toward the casting cavity. Vacuum is applied until metal in the mold is solidifies


Vacuum 
Force Fills Mold

Step 4

Vacuum is removed and mold is open to remove the cast part


Advantages of vacuum casting

  • Good dimensional accuracy
  • Good surface finish
  • Good mechanical properties
  • Reduction in the defects caused by the gases as it uses the vacuum force instead of air pressure used by expandable mold



Disadvantages of vacuum casting

  • High initial cast
  • Complex mold making
  • Only suitable for mass production





Centrifugal casting id one of the main type of the permanent mold metal casting. It uses the centrifugal forces to force the metal into the mold cavity. There are two main types of centrifugal casting

  • True centrifugal casting
  • Semi centrifugal casting


Steps involves in centrifugal casting

Step 1

The first step in centrifugal casting is the mold making. Mold of the centrifugal casting is different from other casting processes because its runner and gating system is totally is horizontal direction.

Step 2

Mold is attached to the circular disk which will rotate to produce the centrifugal forces. Mold is attach to the central sprue by the mean of the runner. Central sprue is the place where hot molten metal is poured.

Centrifuge 
Casting Setup

Step 3

Hot molten metal is poured into the central sprue. When machine start to rotate then metal place in the central sprue start to feel the centrifugal force on it and at some specific force it start to move through the runner into the mold cavity. Centrifugal force is maintain until the metal in the mold solidifies

Centripetal 
Forces Push Molten Material Into The Casting Molds


Centripetal 
Forces Continue To Act On Casting As It Solidifies

Step 4

When metal solidifies machine is stopped and mold is open to remove the cast part. Now the process can be started again.


Advantages of centrifugal casting


  • No high pressure is needed like other permanent mold processes
  • Great surface finish


Disadvantages of centrifugal casting


  • In some cases air can be trapped in the mold and can create defects in the cast part
  • Density of material in the cast part is greater at outer side and lesser at inner side


Densest 
Regions Are Farthest From The Center Of Rotation




Impurities 
Will Be In Regions Closest To Center




Final 
Manufactured Cast Part Of Only Pure, Dense Material

Casting 
Removed From Mold




Cold Chamber 
Die Casting Machine Ready For Manufacture


Cold chamber die casting is one of the two basic types of the die casting in which molten metal is poured manually into a chamber called cold chamber attached to the plunger at one side and mold die at the other side.



Parts of the cold die chamber die casting


  • Power cylinder
  • Plunger rod
  • Plunger
  • Cold chamber
  • Pouring hole
  • Stationary section attached to the base
  • Fixed die half
  • Movable die half
  • Movable plate
  • Guide rode
  • Movement mechanism
  • Stationary section attached to the base
  • Power cylinder for closing die


Steps involves in cold chamber die casting

Step 1

Mold parts are attached are to the plates and plates are attached to each other with great force. 


Step 2

Molten metal is poured manually into the cold chamber through the pouring hole


Correct 
Amount Of Molten Material For A Single Shot Is Poured Into The Shot Chamber

Step 3

Power cylinder forces the plunger and plunger force the molten metal with great force into the cavity. Plunger remains in that position until the molten metal solidifies into the cavity. 


Plunger Has 
Injected The Shot Of Molten Metal From The Cold Chamber Into The Mold


Step 4

After the metal solidifies plunger move back and plates move are open and mold is open to remove the cast part


Cold Shot 
Chamber Open With Piston Back




Advantages of cold die casting


  • High melting metal can be cast
  • Cold chamber die casting products have some advantages like intricate detail, thin walls, and superior mechanical properties


Disadvantages of cold die casting


  • Lower production rate
  • Need more pressure than hot chamber
  • Dangerous for labor


Plunger Is 
Back Up And New Casting Cycle Is Ready To Begin

Hot chamber die casting is one of the two basic types die casting in which molten metal is directly poured into the mold cavity from the molten metal chamber usually called hot chamber and that why this process is called hot chamber die casting


Parts of hot chamber die casting

  • Hot chamber
  • Intake port
  • Shot cylinder
  • Connecting rod
  • Plunger
  • Goose neck passage
  • Casting cavity
  • Mold





Steps involves in hot chamber die casting

Step 1

Mold having the casting cavity is prepared and attached to the hot chamber containing the molten metal

Step 2

Initial position of the plunger is at the top of the chamber and intake port is open due to which molten metal is filled into the hot chamber.


Hot Die Casting 
Operation Is Ready

Step 3

When hot chamber is filled with the molten metal. Shot cylinder force the plunger to move down and after some distance it closes the intake passage and stops the further filling of the hot chamber.

Plunger Has 
Cut Off Intake Port Supplying Molten Metal To The Hot Chamber

Step 4

Now further down ward motion of the plunger will create pressure on molten metal and force it move into the mold cavity. The plunger will remain in this position until the molten metal is solidify. After that it will move back and then the whole process and be start again

Bottom Of 
The Injection Stroke In A Hot Die Casting Process



Advantages of hot chamber die casting

  • High production rate
  • Less danger to labor


Disadvantages of hot chamber die casting

  • Only low melting materials and alloys can be cast
  • Plunger is always dipped into the molten metal due to which its life less




Die casting is the permanent mold metal casting process which uses very high pressure to insert the molten metal into the mold. The process was developed in 1900.

Types of die casting


  • Cold chamber die casting
  • Hot chamber die casting



Parts of die casting machine


  • Power cylinder (for closing die)
  • Stationary section (connected to base)
  • Guide rode (stationary)
  • Movement mechanism 
  • Movable plate (travel on guide rode)
  • Stationary plate (connected to base)
  • Movable die half
  • Fixed die half


Die Casting 
Machine



Steps involves in die casting

Step 1

Like all other metal casting process first process is the mold making. Mold of the die casting is consist of two parts one is fixed and other is movable. Molds are attached to the plates one of them move forward and backward for closing and opening the mold.

Step 2

Some lubricant is sprayed onto the walls of the die so the molten metal does not stick to the wall of the mold

Step 3

Two halves of the molds attached to the plates are closed with great force because when molten metal is added to the mold under pressure it will force the plates to move away. 

Step 4

When two halves of the die is closed then molten metal is forced in the mold at high pressure. Piston or plunger is used to force the molten metal into the die. The pressure is usually 1000 to 50000 psi

Step 5


Molten metal in the die is allowed to cool and when it is cool mold is open and parts are removed from the mold. Ejection pins installed in the mold help in the removal of the parts.


Advantages of die casting


  • Good tolerance
  • Good surface details
  • Thin walls can be manufactured
  • Parts manufactured have superior mechanical properties.
  • High production rate
  • Can be automated
  • Low labor cost
  • Suitable for mass production



Disadvantages of die casting


  • Vent holes need for the eliminating of the gases
  • Trimming is usually needed
  • Ejection pines have small marks on the surface of the part
  • Limited shapes and sizes
  • High cost




Expandable mold vacuum molding is one which uses vacuum pressure to mold around the metal plate pattern. This process was invented by the Japanese in 1970.


Steps involves in vacuum molding

Step 1

Pattern is made from the metal and have specifically design hole in them to withdraw air to create the pressure. A preheated thin plastic sheet is placed over the patter and held tightly with metal plate because of the vacuum.

Step 2

A special design bucket is placed over the pattern and filled with the sand. All other things like spur, runner, riser etc are made. 

Step 3

A plastic sheet is placed over the sand and vacuum is created to held the sand tightly together and so the sand take the shape of the pattern

Step 4 

Vacuum is released and bucket is lifted above the pattern 

Step 5

Other part of the mold is made is the same way and they attached together to get the one complete mold. Then a hot molten metal is poured into the mold to get the required output.



Advantages of vacuum molding

  • No binder is required
  • Sand is recoverable
  • No effects due to moisture because no water is used in this process

Disadvantages of vacuum molding

  • Relatively slow process
  • Process cannot be Mechanization  




There are two types of test use for testing the Impact resistance of any material one is Izod Impact resistance test and other is Charpy Impact resistance test. Both of them use the same principle to test the Impact resistance of any material but still there are may difference in them and our today's article will show these difference between Izod and Charpy Impact  testing 


Izod vs Charpy


Specimen Position

Position of specimen is both the experiment is different from each. In the Izod method, the test material was placed in a vertical position, while in the Charpy method, the test material was placed horizontally.


Point of Strike 

Point at which the hammer strike the specimen is different for both of them. In Izod test hammer strike at the upper tip of specimen while in Charpy test hammer strike at point of notch but in opposite direction 

Direction of Notch

Face of specimen which faces the striker is different. The notch face in the izod test is facing the striker, fastened in a pendulum, while in the charpy test, the notch face is positioned away from the striker.

Type Of Notch
In hardness testing two types of notches are used V-notch and U-notch. In the Charpy method, there are two kinds of notches, the V-notch and the U-notch, while in the Izod method, there is V-notch is used

Specimen Dimensions

Even if you are testing the same material the test specimens have different dimensions for each test. The basic Izod test specimen is 75 x 10 x 10mm (2.95" x 0.394" x 0.394"); the basic Charpy test specimen is 55 x 10 x 10mm (2.165" x 0.394" x 0.394") 

Hammer Type

Hammer which use as striker is different in both test. Izod use Farming hammer as striker where as Charpy use Ball Pin hammer as striker



Permanent Mold Casting Processes are one in which there is a one mold made of metal which could be used again and again many times. Mold material is usually cast iron or steel. Mold is usually consist of two parts, which are attached to each other and metal is poured and when metal cools, mold is opened and part is removed


Basic Permanent Mold Casting Processes

  • Die casting
  • Hot chamber die casting
  • Cold chamber die casting
  • Centrifugal casting
  • True centrifugal casting
  • Semi centrifugal casting
  • Pressure casting
  • Vacuum molding casting
  • Slush casting
  • Ingot manufacturing

Steps involves in Permanent Mold Casting Processes

Step 1

Two parts of the mold are heated and are spared with some material which prevent the molting material from sticking with mold walls.



Step 2

If there is any internal cavity core is place in the mold and mold is closed


Step 3

After the mold is closed molten metal is poured into the mold.

Step 4

When the molten material is cool then then mold is open and part is removed


Applications Permanent Mold Casting Processes


  • Because of the high initial cost of the mold. These types of process are suitable for the mass production
  • Parts casted are piston, pump bodies, car engine parts, air craft parts etc
  • Metals cast: aluminum, magnesium, copper-base alloys, and cast iron

Advantages Permanent Mold Casting Processes


  • High dimensional accuracy 
  • Good surface finish
  • High production rate
  • Low cast of product

Disadvantages Permanent Mold Casting Processes


  • High initial cost
  • Limitation of material (low melting metals only)
  • Only simple geometry





In Pro/ENGINEER holes are created using the HOLE dialog box. The HOLE dialog box is displayed when you choose Insert > Hole from the menu bar or PART > Feature > Create > Solid > Hole from the Menu Manager.

You can create three types of holes using the HOLE dialog box.
  • The first type is a straight hole,
  • the second is a sketched hole,
  • the third is a standard hole.          


straight hole

Straight holes are the holes that have a circular cross-section having a constant diameter throughout the depth. They start at the placement plane and terminate at the user-defined depth or at the specified end surface.

sketched hole

The Sketched option allows you to sketch the cross-section for the hole that is revolved about a center axis. This option is used to draw custom shapes for the hole. When you choose this radio button in the HOLE dialog box, the system opens a new window with the sketcher environment. The cross-section for the hole is sketched using the normal sketcher options available. While drawing the sketch, a center line must be drawn that acts as the axis of revolution for the section of hole. The sketched holes can be a blind or a through hole depending upon the dimensions of the section sketch.

standard hole

The holes created using the Standard Hole option are based on industry standard fastener tables. The Standard Hole option allows you to create two types of holes, Tapped holes and Clearance holes. In the Tapped holes, the cosmetic thread is included in the hole, whereas in the Clearance holes, the cosmetic threads are not included.

Hole Placement area


In the Hole Placement area of the HOLE dialog box all the parameters that will define the placement of a hole are specified.



Linear. When you select this option, you are prompted to specify the distances from two linear references. Generally, these linear references are the edges of the planar surface on the model, any two planar surfaces or axes, or a combination of any of these.

Radial. This option is used to create a hole that can be referenced to an axis. When you select this option, you are prompted to select an axial reference and an angular reference to place the hole. The distance from the axis is entered in the Distance edit box and angle is entered in the Angle edit box that is displayed when you select the axis and the plane for the angular reference. This option is usually used to create holes on flanges

Diameter. This option creates a diametrically placed hole. When you select this option, you are prompted to select an axial reference and an angular reference to place the hole.

Coaxial. This option creates a hole coaxially. When you select this option, you are prompted to select an axis. No dimensions are required to place a coaxial hole. 

Last Words !

So, My loyal Engineers that was all about topic. I am sure you have enjoyed and understood each and everything. If you still have any queries or questions please comment below or if you think you have some better tips or steps that I have missed please share with me via the comment box below. I will appreciate your efforts. Take A Lot Of Care!



Manufacture is derived from two Latin words manus (hand) and factus (make); the combination means “made by hand”. “Made by hand”accurately described the manual methods used when the English word “manufacture” was first coined around 1567 A.D. Most modern manufacturing is accomplished by automated and computer-controlled machinery that is manually supervised

Introduction

Manufacturing is the application of physical and chemical processes to alter the geometry, properties, and/or appearance of a given starting material to make parts or products; manufacturing also includes assembly of multiple parts to make products Manufacturing is almost always carried out as a sequence of operations



Manufacturing is the transformation of materials into items of greater value by means of one or more processing and/or assembly operations Manufacturing adds value to the material by changing its shape or properties, or by combining it with other materials that have been similarly altered


Manufacturing Importance


Technologically 
Technology can be defined as the application of science to provide society and its members with those things that are needed or desired
  • Technology provides products that help our society and its members live better
  • What do these products have in common? They are all manufactured
  • Manufacturing is the essential factor that makes technology possible




Economically
Manufacturing is a means by which a nation creates material wealth
  • In the U.S. manufacturing constitutes ~ 20% of GNP
  • Government is as much of GNP as manufacturing,but it creates no wealth






Historically
Historically, the importance of manufacturing in the development of civilization is usually underestimated
  • Throughout history, human cultures that were better at making things were more successful
  • Making better tools meant better crafts & weapons 
  • Better crafts allowed the people to live better
  • Better weapons allowed them to conquer other cultures in times of conflict
  • To a significant degree, the history of civilization is the history of humans' ability to make thing



Manufacturing materials

Materials use in manufacturing are Classified as follow


1. Metals
2. Ceramics
3. Polymers
4. Composites

Their chemistries are different, their mechanical and physical properties are dissimilar, and these differences affect the manufacturing processes that can be used to produce products from them



Manufacturing Processes

Manufacturing processes are classified into Two basic types
  • Processing operations
  • Assembly operations

1. Processing operations - transform a work material from one state of completion to a more advanced stateOperations that change the geometry, properties, or appearance of the starting material

2. Assembly operations - join two or more components in order to create a new entity

Manufacturing Industries

Manufacturing Industries can be classified as:

1. Primary industries - those that cultivate and exploit natural resources, e.g., agriculture, mining

2. Secondary industries - take the outputs of primary industries and convert them into consumer and capital goods - manufacturing is the principal activity

3. Tertiary industries – service sector of the economy

Contact Form

Name

Email *

Message *

Powered by Blogger.
Javascript DisablePlease Enable Javascript To See All Widget