METAL PROPERTIES LIKE-Hardness,toughness and strength

Hardness:- A material ability to withstand frictional force, for example, diamond is extremely hard you can't easily scratch a  diamond but here comes an interesting point although diamond is hard it is not tough you can shatter a diamond with a blow of a strong hammer. it means not every material which is hard is equally tough.

Strength:- It is the ability to resist deformation or say the amount of force necessary to deform a material body.the higher the force required for deformation higher the strength it bears.

Toughness:- It is defined as how well a material can resist fracture when force is applied it requires both strength and ductility, for example, take a silicon-based toy known as silly putty it did not break easily is not it a tough one.

apart from above discussions some material posses all those above properties like drill bits they are hard, tough and have good strength.

Now you are on verge of saying yourself a material engineer at least you can now describe materials in technical words 

#hardness,  #shubham chaurasiya, #toughness

FUNDAMENTALS OF MECHANICAL VIBRATION

GUYS HERE I PRESENT YOU MY LITTLE EFFORT;

I have made a simplified easily understable ppt and has uploaded it on slideshare for your help 

ABOUT THE PPT

It is made to understand the basic definitions and terms used in mechanical vibration which is one of very important subject of MECHANICAL ENGINEERING and GATE so to have a quick look you should go through this slides but go through this slides only for a quick revision this is not meant for building up your concepts from ground level for that i would recommend you go through some good books  

link to slide

WHAT IS ABRASIVE GRADE/GRIT SIZE ?

GRIT SIZE
"The grit size indicate the abrasive grade on the abrasive side of paper."

It follows inverse relation with size of abrasive grain
i.e a higher grit number a smaller abrasive grain and vice versa

A “P” in front of the grit size indicates that the product is graded in accordance with the European FEPA standard

USE OF TERMS COARSE,MEDIUM AND FINE
This terms are used in conjugation with the Grit size of abrasive.

G00 Rapid Traverse

G00  is the basic G-code for CNC programming. It is used to perform rapid traverse

That mean we always want to make a tool to a position that we want fastly

When you finish one cutting on your part is one position, and you need to move you cutting tool to

the next cutting position, you often use G00 to move tool fastly to the place you wanted.

#NOTE:-you can't use G00 when you're cutting the material of your part. G00 is used to save your time not for cutting.its just for positioning your tool in a quick manner.

AMAZING SCIENCE EXPERIMENT

A MUST WATCH VIDEO FOR SCIENCE LOVERS..............................

AUTOMATION AND ITS TYPES CAD/CAM

Automation of production systems can be classified into three basic types:

1. Fixed automation (Hard Automation)

2. Programmable automation (Soft Automation)

3. Flexible automation.

1. Fixed automation (Hard automation): Fixed automation refers to the use of special purpose equipment to automate a fixed sequence of processing or assembly operations. Each of the operation in the sequence is usually simple, involving perhaps a plain linear or rotational motion or an uncomplicated combination of two. It is relatively difficult to accomodate changes in the product design. This is called hard automation.

Advantages:

1. Low unit cost

2. Automated material handling

3. High production rate.

Disadvantages:

1. High initial Investment

2. Relatively inflexible in accommodating product changes.

2. Programmable automation (Soft automation): In programmable automation, the production equipment is designed with the capability to change the sequence of operations to accomodate different product configurations. The operation sequence is controlled by a program, which is a set of instructions coded. So that they can be read and interpreted by the system. New programs can be prepared and entered into the equipment to produce new products.

Advantages:

1. Flexible to deal with design variations.

2. Suitable for batch production.

Disadvantages:

1. High investment in general purpose equipment

2. Lower production rate than fixed automation.

Example: Numerical controlled machine tools, industrial robots and programmable logic controller.

3. Flexible Automation:  Flexible automation is an extension of programmable automation. A flexible automation system is capable of producing a variety of parts with virtually no time lost for changeovers from one part style to the next. There is no lost production time while reprogramming the system and altering the physical set up.

Advantages:

1. Continuous production of variable mixtures of product.

2. Flexible to deal with product design variation.

Disadvantages:

1. Medium production rate

2. High investment.

3. High ‘unit cost relative to fixed automation.

ADVANTAGES AND DISADVANTAGES OF WELDED OVER RIVETED JOINTS

      

 

 

    Advantages:

• The welded structures are usually light in weight compared to riveted structures. This is due to the reason, that in welding, gussets or other connecting components are not used.

• The welded joints provide high efficiency, which is not possible in the case of riveted joints.

• Alterations and additions can be made easily in the existing structures.

• Welded structures are smooth in appearance, therefore it looks pleasing.

• A welded joint has a great strength. Often a welded joint has the strength of the parent metal itself.

• It is easily possible to weld any part of a structure at any point. But riveting requires enough clearance.

• The process of making welding joints takes less time than the riveted joints.

• Shape like cylindrical steel pipes can be easily welded. But they are difficulty for riveting.

• The welding provides very strong joints. which can’t be bended easily. This is in line with the modern trend of providing rigid frames.

• In welded connections, the tension members are not weakened as in the case of riveted joints.

    Disadvantages:

• For making weld joints using weld symbols requires a highly skilled labour and supervision.

• Since there is an uneven heating and cooling in welding process during fabrication, therefore the members may get distorted or additional stresses may develop.

• Since no provision is kept for expansion and contraction in the frame, therefore there is a possibility of cracks developing in it.

• The inspection of defects in welding work is more difficult than riveting work.