Tag: Material science

How cement is made

How cement is made

How cement is made

06/12/17

“How is cement made?”

 

Cement is one of the most versatile materials on the planet. However, how exactly is it made? Well, let’s use our engineering mindset to find out. First, we must gather up its primal ingredients: limestone, clay, and others. Then, we must crush these rocks. Then we must combine this crushed material with other ingredients such as iron ore and feed it into a cement kiln. The kiln will then heat all of these ingredients, burning away some, and producing a red-hot compound known as clinker. This clinker must then be ejected into a cooling plant, and be mixed with gypsum and limestone to eventually form the cement that we know and love.

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How materials in a composite bond

How materials in a composite bond

How materials in a composite bond

06/06/17

“How do materials in a composite bond with one another?”

 

In all composites, there are two bonding materials. However, have you ever wondered how exactly do they bond with another without merging? Well, let’s use our engineering mindset to find out. If we look closely, then we will notice that one material (known as the “matrix” or “continuous” material will serve as a medium that surrounds the other material (known as the “discontinuous” or “fiber” material), therefore creating the composites that we know and love!

Refractory materials

Refractory materials

Refractory materials

05/31/17

“Are there materials that retain their strength at exceedingly high temperatures?”

 

For processes such as nuclear power generation or incinerators, materials must be able to withstand heavy loads. However, the high temperatures that they operate at often destroy the useful properties of most materials. So are there materials that can withstand high temperatures? Well, after many years of hard work spent in research, Materials Engineers and Scientists have been able to classify such materials as refractory materials. Refractory materials can be divided into two types, acidic refractories with SiO2 content more than 93% used for their erosion resistance, and basic refractories for higher thermal resistance

Scratch tests

Scratch tests

Scratch tests

05/26/17

“How can we determine the fracture strength and resistance of a material using simple devices?”

 

Determining the fracture strength and resistance of a material is of the utmost practical use to the engineering profession. However, how exactly can figure them out experimentally in a cost-wise fashion? Well, let’s think about this using our engineering mindset. We already know the strength of many other materials. And we also know that if one material is able to scratch another, then it is the stronger of the two. So what if we were to take this method and use it to organize all of the different materials we know? Well, this is the fundamental idea behind the scratch test, and it is used for economically conscious projects around the world.

Hardness

Hardness

Hardness

05/24/17

“How can we quantify a material’s resistance to permanent shape change?”

 

When under a compressive force, materials tend to deform. However, some materials are more resistant to deformation than others. This resistance to compressive deformation can be quantified the concept of hardness. Hardness can be measured by varying a controlled force and recording the resulting deformations.  

Tires

Tires

Tires

05/23/17

“What makes tires so useful?”

 

        The vast majority motorized vehicles on this planet are able to transport passengers because of one simple invention, tires. However, what specific properties do they have that make them so useful? Well, let’s find out using our engineering mindset.

To begin, let’s analyze what makes a tire a tire. Tires are composed of a combination of synthetic rubber, natural rubber, fabric, and wire, fashioned with a thread and a body. Once manufactured, tires are threaded with grooves to provide traction, filled with air to provide buoyancy, and finally fitted onto vehicles.

        Tires are well regarded around the world for their strength, flexibility, and cost. However, some downsides associated with these tools are their tendency to hydroplane (when a tire runs over a damp surface and become uncontrollable) and their production and decomposition process can be destructive to the environment (particularly if they are burned)

Magnetic domains, hysteresis, and hard/soft magnets

Magnetic domains, hysteresis, and hard/soft magnets

 

Magnetic domains, hysteresis, and hard/soft magnets

05/22/17

“How do magnetic fields come about and how can we apply this knowledge?”

 

The subatomic interactions in a magnetic object from material properties give rise to its macroscopic phenomena. Magnetic materials are composed of divisions known as magnetic domains that have a random magnetic field direction. When an external magnetic field is applied to a material, all of these domains will align with said field and produce a magnetic force. The magnitude of this magnetic force emanating from the object will be the result of the summation of the magnetic fields from all of the individual domains.

This theory can be applied using a hysteresis loop operates as follows. Take a piece of metal. Now run a coil around it. Generate an AC voltage. At t = 0, there will be magnetic activity in neither the metal nor the coil. When the voltage is increased, it will cause the domains to line up, eventually reaching a maximum value. Now pull the voltage in the other direction. When the voltage is equal to zero, the metal will have some residual magnetic field in it as a result of the shifting domains. If we pull the voltage into a negative state, then eventually it will reach another maximum (at the negative of the original boundary). If we reverse the direction of the current again to zero, then we will also have some residual magnetic field at zero. And if we increase the voltage in the positive direction, then we will reach the maximum again (Schuster, Doc).

 

Based upon their hysteresis profile, a material may be classified into either a hard magnet or a soft magnet. The former has a large profile, and are often used for energy intensive applications such as permanent magnets, while the latter has a smaller profile ideal for use in low energy loss application such as transformers.

Atulasimha, Jatulasimha. “Magnetism.” Magnetism for General Audience. Virginia Commonwealth University, 8 Nov. 2015. Web. 22 May 2017.

 

Callister, William, and David G. Rethwisch.Materials Science and Engineering: An Introduction. 9thed. , John Wiley & Sons, Inc., 2014.

 

Magnetic Hysteresis or I KNOW WHAT YOUR MAGNET DID LAST SUMMER | Doc Physics. Dir. Doc Schuster. Perf. Doc Schuster. Youtube. Doc Schuster, 25 Feb. 2014. Web. 22 May 2017.