Please I need to answer these questions from the book make i

Please I need to answer these questions from the book. (make it typing)
Degarmo\'s Materials and Processes In Manufacturing.. by JT. Black, Ronald A, Kohser.
Eleventh Edition
chapter 10

product choices
1) A pair of scissors
2) Standard open-end wrench
3) The frame of a 10-speed bicycle
4) A commemorative coin for a corporation\'s 100th anniversary
5) A moderate- to high-quality household frying pan.
Evaluate & answers the following questions.
2- what are the major properties or characteristics that the material must possess in order for the product to function?
3- what material (or materials) would you suggest and why?
4- how might you propose to fabricate this product?
5- would the product require heat treatment? for what purpose? What kind of treatment?
6- Would there be concerns relating to environment? Recycling? Product liability?

Solution

Standard open-end wrench:

Wrench also known as spanner is a tool used to provide mechanical advantage in applying torque to turn rotary fastener such as nut and bolts.

Q1. What are the major properties or characteristics that the material must possess in order for the product to function?

Material selection is very important phase in designing of wrench. Material selection of wrench should consider following aspects:

1. Type of application like heavy duty, medium duty, and light duty.

2. Cost of material

3. Actual application area of wrench like Automotive workshop, carpenter shop, heavy industry workshop etc.

4. Quality of wrench which we want to deliver.

Based on the above mentioned factors following are the important mechanical characteristics which material of wrench should possess:

1. Good strength: Strength is very crucial factor as it is directly related to productivity & capability to provide torque of wrench. On the basis of strength generally wrenches are made up of alloy steel which possesses good strength (approximately 650MPa tensile strength)

2. Endurance strength: As the wrench is constantly subjected to cyclic loading, it should possess good endurance limit. It decides the life span of wrench.

3. Corrosion resistance: Apart from the above mentioned qualities the material should also possess good resistance against corrosion as the wrenches are generally used in outdoor and prone to corrosion environment. Hence generally wrenches are chrome plated.

Q2. what material (or materials) would you suggest and why?

1. Alloy steel: Alloy steel would be the most favorable material for wrench as it possesses good tensile strength. Also hardening treatment on the alloy steel improves its endurance limit and they are inherently corrosion resistant.

2. Chrome vanadium alloy steel: This would also be the best choice material for producing high quality wrench. But it comes with higher cost.

3. Carbon fiber: We can leverage the recent development in the field of composite material. Carbon fiber wrench would be light weight wrench with required strength and endurance strength.

Q3. how might you propose to fabricate this product?

Generally forging would be suitable process for fabrication of wrench as it imparts residual stresses in the component and hence improves its strength.

Following steps will be required for manufacturing a wrench:

1. Creation of rough shape with thermal forging

2. Annealing process & deburring the component

3. CNC m/c cutting for achieving desired dimension

4. Heat treatment to increase toughness

5. Providing protective layer to improve corrosion resistance.

Q4. Would the product require heat treatment? For what purpose? What kind of treatment?

Yes heat treatment is necessary for improving toughness of wrench. It improves fatigue life of wrench.

Hardening and tempering will be suitable heat treatment.

Q5. Would there be concerns relating to environment? Recycling? Product liability ?

Working of wrench does not produce any kind of harmful substances to environment. The only concern will be during manufacturing process. Manufacturing processes should be followed environment friendly approach.

Recycling is quite easy as the metal of wrench can be easily melted and used for some other application.

There will not be any concern related to product liability as the faulty piece would not cause damage to anyone and it can be easily replaced with newer one and indeed there are less chances of failure of wrench in warranted period.