Diagrma de esfuerzos estructuras, metodologia

U0.C01.

Describe the differences between Materials Science and Engineering.

We can define the Materials Science as the “discipline that studies the relationship that exists between the structure and the properties of materials”. On the other hand, we can define Materials Engineering as the “discipline that designs the structure of a material to achieve a certain set of properties based on a correspondence between structure and known properties.” In this way, we can affirm that in Materials Science, existing phenomena are studied, and in engineering, we seek to create based on our improvement needs, drawing on previous knowledge.

Another point of differentiation is found in the aim of their designs. Scientists "design experiments to validate theories" while engineers "design machines capable of validating theories."

While scientists "prefer abstract knowledge (although they rely on tacit knowledge)" engineers "prefer applied knowledge".

U0.C02.

According to your criteria, what property /ies would you look for in the blade material of a knife?

-Corrosion resistance: The ability of the steel to resist deterioration because of reaction with its environment

-Hardness: A measure of the steel's ability to resist permanent deformation

-Toughness: The steel’s ability to absorb energy prior to fracturing

- Ease of Resharpening

- Edge Retention: The ability of the steel blade to hold an edge without frequent resharpening

- Hardenability: The ability of a steel to be hardened (through the heat-treating process)

- Strength: The steel’s ability to resist applied forces

- Ductility: The steel's ability to flex or bend without fracturing

- Initial Sharpness: The sharpness of the blade "out of the box"

- Wear Resistance: The ability to resist wear and abrasion during use

- Manufacturability: The ease with which steel can be machined, blanked, ground, and heat-treated (made into a blade)

- Stiffness (meaning modulus): the extent to which it resists deformation in response to an applied force

U0.C03.

In the past, plastic bicycles have been tried on several occasions, but they were very flexible. What property limited their use according to this? Justify your answer.

Flexibility is lack of stiffness. The stiffness of a structure depends on its shape, size and value of Young's modulus (E). We can mention that the value of the Young’s modulus (E) is a design-limiting property in design for stiffness. In bicycle design the values of E offered by plastics are insufficiently large. To increase the stiffness, plastic can be reinforced the with carbon or fiberglass.

U0.C04.

According to your criteria, what property /ies would you look for in a glove to be used to operate an oven?

-Low thermal conductivity: hands should be protected from high temperatures (to avoid burns)

-Flexibility: they are used with hands (they are articulated)

-Tolerance of water (to be washed)

-Maximum operating temperature: it should be high (ovens reach temperatures over 200 degrees C).

U0.C05.

According to your criteria, what property or properties would you look for in the material for the filament of a light bulb?

-Good Electrical conductivity

-High operating temperature

-Ductility (ductility to enable it to be drawn to fine wire)

U0.C07.

Identify three applications where it is necessary to use a material with high rigidity and low weight. Justify your answer.

-Paperboard for boxes: a rigid material is needed so that the box can hold the weight of the objects it contains without breaking. If the box broke, it would not be used to transport objects. In addition, as its function is the transport of goods, it cannot have a high weight.

-PET for food packaging: it is a plastic of high rigidity, as it must contain substances without deforming and when caught it must maintain the shape. In addition, because it is used for food, it cannot have a high weight because it would hinder its handling.

-Polypropylene (PP) for orthopaedics: must be rigid because when applied forces (when tightening the teeth if it is a dental splint or when walking in the case of a stabilizing orthosis) must maintain the form to fulfil its function of restraint. In addition, it cannot have a high weight because they are used by human beings in their functions of locomotion.

U0.C08.

Steel is often coated with a thin layer of zinc when used exposed to the weather. What characteristics do you think this coating brings? What precautions do you think should be taken when producing it? Do you think that the recyclability of steel will be affected?

Zinc acts as a protection against atmospheric corrosion of sheets and pieces made of steel in its different alloys. The function of this metal is to act as a physical barrier that isolates the metal substrate from the medium and the corrosive agents.

When producing it, caution should be taken when making the coating since it should be homogeneous and without pores. Through the pores or uncovered parts, Steel could be oxidized and we could not visualize this oxidation.

It is also important to use only the necessary amount of zinc to save on material costs.

The presence of the zinc coating on the steel does not restrict the recyclability of the assembly, since it is possible to separate and recover the two original metals taking advantage of the fact that the volatilization temperature of the zinc is lower than the melting temperature of the steel.