31.8.18

Casting | Types of Casting Defects.

Casting | Types of Casting Defects.

Casting-

A mould cavity is created out of sand or some permanent material and liquid metal is poured into this cavity and the product is taken out after solidification.

Types of Casting Defects

1) Gas Defects
 2) Moulding material Defects
3) Metallurgical Defects 
4) Pouring metal Defects

1. Gas Defects:-

These defects occur due to improper gas passing tendency of the mould. These defects are further classified into few types
(i) Air inclusions: - Air trapped in the final casting product. It is caused due to improper ventilation. These defects can be avoided by choosing appropriate pouring temperature and improving gating practice by reducing turbulence.
(ii) Open blows: - Spherical or elongated cavities formed on the surface of the casting product
(iii) Blow holes: - Cavities formed inside the final casting product
These open/blow holes are generally caused by the moisture present in the mould cavity or core it is also caused due to lower permeability and lower ventilation of mould. It can be avoided by providing proper ventilation.

2. Moulding Material Defects: - 

These defects are caused by the characteristics of the moulding sand material these are classified into few types: -
(i) Run out- Leaking of molten metal out of the mould. It is generally caused by faulty making of mould or faulty moulding flask.
(ii) Fusion – Brittle and glassy appearance on the casting product due to fusion of sand grains with molten metal.

27.8.18

Plastic | Plastic Moulding and its Types

Plastic moulding.

Plastic moulding is the process of shaping plastic using a rigid frame or mould, the techniques allow for the creation of objects of all shapes and sizes with huge design flexibility for both simple and highly complex designs. Plastic moulding is the process of manufacturing by shaping liquid or pliable raw material using a rigid frame called a mould,

Types of Moulding Processes includes: -

A) Blow moulding-

Blow molding is a manufacturing process by which hollow plastic parts are formed. In general, there are three main types of blow moulding: Extrusion blow moulding, Injection blow moulding, and Injection stretch blow moulding. The blow moulding process begins with melting down the plastic and forming it into a parison or in the case of injection and injection stretch blow moulding (ISB) a preform. The parison is a tube-like piece of plastic with a hole in one end through which compressed air can pass.

Extrusion Blow Moulding

Extrusion Blow Moulding plastic is melted and extruded into a parison. This parison is then captured by closing it into a cooled metal mould. Air is then blown into the parison, inflating it into the shape of the hollow bottle, container, or
Part. After the plastic has cooled sufficiently, the mould is opened and the part is ejected. Continuous and Intermittent are two variations of Extrusion Blow Moulding.

Injection Blows Moulding (IBM)

Injection blows moulding is used for the production of hollow glass and plastic objects in large quantities. In the IBM process, the polymer is injection moulded onto a core pin; then the core pin is rotated to a blow molding station to be inflated and cooled. This is the least-used of the three blow molding processes, and is typically used to make small medical and single serve bottles. The process is divided into three steps: Injection, Blowing and Ejection.

Injection Stretch Blow Moulding

Injection Stretch Blow Moulding process, the plastic is first moulded into a "preform" using the injection molding process. These preforms are produced with the necks of the bottles, including threads on one end. These preforms are packaged, and fed later into a reheat stretch blow molding machine. In the ISB process, the preforms are heated above their glass transition temperature, then blown using high-pressure air into bottles using metal blow molds. The preform is always stretched with a core rod as part of the process.

24.8.18

CATIA | Basic Interview Questions And Answers.


CATIA  Interview Questions and Answers of CATIA.

CATIA is an acronym for Computer Aided Three-Dimensional Interactive Application. It is the most proficient, powerful and highly popular CAD i.e. computer aided design software. It is created, developed and owned by Dassault Systems of France. 

Application of CATIA

CATIA is among the very few software which has its application in about every industrial sector. It is mostly used by the designer team. The designer team of any organization needs to create a digital copy of any object which has to be manufactured. This digital copy can be created with much ease by using CATIA. It is mostly found in companies who are associated with design and manufacturing of products.

1. What is Full form of CATIA?

A. Computer Aided Three Dimensional Interactive Application.

2. What Is The Kernel Of CATIA?

A. CNEXT 

3. What is the save extension of sketcher file?

A. .CAT Part

4. Does CATIA V5 work on UNIX Platform?

A. Yes

5. Is it possible to increase the size of plane boundary representation & how?

A. Yes, Go for Tools-Options- Infrastructure-Part structure-Display.

6. What Are the Default Units of LMT (length, Mass and Time)?

A. mm, Kg, Second. 

7. Is it possible to hide specification tree?

A. Yes, with help of F3 button, but the option in Tools command must be checked to allow this.

21.8.18

Creo | Creo Parametric Interview Questions And Answers.


Creo Parametric Interview Questions:

Creo Parametric.

Creo is a powerful software which is a combination of various designing tools. It is popularly used by many leading manufacturing companies across the globe. It was designed by PTC (Parametric Technology Corporation).

1. What are the file extensions given to sketches, parts, assemblies, drawings?

A. Sketches - .sec,
Parts- .prt,
Assemblies- .asm,
Drawings- .drw

2. What is the use of config.pro file?

A. The config.pro file contains configuration options which control the behavior of Creo. This file also contains user macros which are called map keys.

3. What is a trail file?

A. The trail file is a record of every menu pick and screen pick and keyboard input during an entire session of pro/engineer. This file can be retrieved and edited and replayed to retrieve work lost during an unexpected failure of a session.

4. What is the meaning of "store back"?

A. 'Store back' refers to the behavior in which an object is stored back to the directory from where it was opened not necessarily the current working directory.

5. What is the difference between File -> Erase and File -> Delete?

A. File erase removes the object from the ram of the computer and file delete removes the object from the disk or hard drive of the computer.

6. What is the difference between File -> Save and File -> Backup?

A. File save stores the object in the directory where it was opened from and file backup copies the object to the specified directory using the same name.

7. After performing a File, Save As, what is the current object?

A.  After performing a file save as command the current object is not a new object it is the old object.

20.8.18

Properties of Materials.

Properties of Materials.

Properties of Materials.

Mechanical properties of metals include those characteristics of Materials that describe the behavior under the action of external forces.

Elasticity:-

When Material subject to any External load it gets deform, the ability of any Material to Regain its Original shape after removal of External Load is Known as Elasticity.

Plasticity:-

When Material subject to any External load it gets deform, Material does not regain its Original shape after removal of External Load is known as Plasticity.

Ductility:-

It is the capacity of a material to go for maximum deformation under the action of tensile load without fracture.
Examples: Mild Steel, Lead, Nickel, Brass, Monal Metal, Manganese, Copper, Aluminum.

Brittleness:-

Brittleness is the property opposite to that of Ductility.
Brittleness is the lack of Ductility, i.e. Material cannot be stretches in Brittle.
 Materials failure takes place with a relatively smaller deformation means material to get broken into pieces when subjected to any load.
For Brittle Material fracture Point & Ultimate Points are same.
Examples:-Cast Iron, Glass, Concrete.

18.8.18

What is plastic? Types of plastics?

What is plastic?

Plastics are long Chain synthetic polymers having Isotropic Characteristics.
They have great tendency to deform, also high strength stiffness.
Plastics are formed by the Addition polymerization or Condensation polymerization.


Addition polymerization:-

In Addition polymerization process breaking the double carbon bond in Bi-functional polymers so that chain can be formed.
Various monomers used in this process such as Ethylene, Styrene, Vinyl Chloride, Propylene.

16.8.18

WHY SHOULD BE A DESIGN ENGINEER…?

WHY SHOULD BE A DESIGN ENGINEER…?

According to a recent status from a leading job portal in India, there are about 35000 job posting who require Design Engineer. In India, The average salary of Design Engineer is about 4 Lacs, where with experience, the student can also have the package of about 10 Lacs. With increase of industrialization, the demand for design engineers will also grow in the future. Let’s have a look at some advantages of becoming a Design Engineer.




o    Challenging Career

    With the technological advancement, the parameters are always changing. So a design engineer has to also keep them updated to face and tackle every designing challenge. Design Engineers have to deliver quality designs in the required time frame. Thus this position requires great dedication and timeliness. You can put your creativity to test, every time you have a designing task assigned to you.

o    Complete Desk Job


      Most of the Mechanical or Automobile Engineering students prefer a desk job, especially Female engineers. If you have the same preference, Design Engineer is a saviour for you. This is complete desk job, where the professional has to sit for long hours either creating designs or monitoring it.

o    Lavish Job


     As mentioned earlier, Design Engineers have great earning opportunity once they have some amount of experience to back their talent. Moreover, designing job posting are generally at the corporate offices of every big manufacturing company. Hence professional can enjoy their life to the maximum.