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(a) Identify the main processes used to manufacture the metal face guard of the hurling helmet shown - Leaving Cert Engineering - Question Question 1 - 2012
Question Question 1
(a) Identify the main processes used to manufacture the metal face guard of the hurling helmet shown. (b) Explain the term allotropy with reference to carbon steel.
Worked Solution & Example Answer:(a) Identify the main processes used to manufacture the metal face guard of the hurling helmet shown - Leaving Cert Engineering - Question Question 1 - 2012
Step 1
Identify the main processes used to manufacture the metal face guard of the hurling helmet shown.
Answer
The main processes involved in manufacturing the metal face guard of the hurling helmet include:
- Bending: The bars used for the face guard are first bent into the required shapes. This process allows the metal to be formed into a precise configuration necessary for fitting onto the helmet securely.
- Welding: Once the bars have been bent, they are welded together. This involves using heat to melt the metal at the joint and allowing it to cool to solidify, ensuring a strong and durable assembly.
Step 2
Explain the term allotropy with reference to carbon steel.
Answer
Allotropy is the ability of a material to exist in different forms. In the case of iron, it refers to how the structure of iron can vary depending on temperature and composition:
- Alpha Iron (Ferrite): At lower temperatures, iron exists as alpha iron, which has a body-centered cubic (BCC) crystal structure. In this form, iron can accommodate a small quantity of carbon.
- Gamma Iron (Austenite): Above certain temperatures, iron transforms into gamma iron (austenite), characterized by a face-centered cubic (FCC) structure. This form can dissolve more carbon, up to about 1.7%.
Upon cooling from austenite to ferrite, carbon must come out of solution, leading to the formation of different compounds. For example, when iron and carbon are combined, one prominent compound is cementite, which contributes to the hardness of carbon steel. All these phases indicate how a simple element like iron can exist in multiple forms depending on its atomic arrangement.