Практика Shadowing: What is Materials Engineering? - Изучайте разговорный английский с YouTube

Materials engineering is about designing,

⏸ Пауза

Скорость:

273 предложений

Если предложения слишком короткие или длинные, нажмите Edit, чтобы их изменить.

Materials engineering is about designing,

processing, testing, and discovering materials, mainly solids.

It's about analyzing the structure,

properties, performance, and processing of materials and objects.

In fact, if you do a Google search for materials engineering right now,

you'll see this come up.

And this basically says that all four of these things are connected,

and by changing one, like the structure of a material,

you change everything else.

But let's first start with careers,

like what would a materials engineer be doing or be needed for?

Well, like I said in our aerospace video,

aircrafts traveling at supersonic speeds are subject to

so much friction from the air molecules that the aircraft can be heated to several hundred degrees Fahrenheit.

The materials engineer might have to figure out or design the best material to use that can handle these conditions.

Materials engineers are very important when it comes to cars.

Did you know cars are designed to crumple when they are in a crash?

They are made to have that accordion-like response and it saves lives.

The cars crumple to absorb energy from the crash and they need the right material and structure to do this.

If the car was extremely tough and no damage was done in a crash,

all that energy would be transferred to the driver.

The frame of the car may have harder metals at the top compared to the bottom

because of how that will transfer energy from a crash away from a driver.

How a car will be impacted in a crash is kind of predictable because that's how engineers design them,

and a huge part of this is picking the right materials with the right properties.

And on that topic, materials engineers deal a lot with fracture and how components fail.

So you could work in a failure analysis lab where you have broken parts

that can range from jet engines to computer parts and have to figure out what went wrong,

and it's really about looking at the structure and material itself.

The materials engineer who wrote this video with me had a

job in a failure analysis lab where he had to look at the landing gear of a plane.

But not shown here, the landing gear had a huge crack around it which almost broke it during landing.

So he had to use a microscope and analyze the microstructure of the landing gear.

This is a micrometer scale picture but tells us a lot.

At this scale you can actually see where the crack originated from and how it physically propagated through the structure.

The crack isn't shown here,

but you'll learn how to analyze these in school.

And guess what?

Just like with the car,

landing gear is designed to fail like this.

The material and structure is designed so that if it failed,

it wouldn't just snap.

It would crack along a certain path so that during landing,

even though there was a crack,

the plane could still make it through the runway.

So a materials engineer could also design how a structure will fail if and when it does.

Then based on the failure analysis results,

we can design even better landing gear and various other structures.

Or maybe if a computer part failed,

you're not going to do circuit analysis like an electrical engineer would,

but you may be looking for a soldering issue where there's a connection problem

and a component came loose from the circuit board.

So again, you'd have to analyze this on a micro scale using a microscope and determine what happened and why.

They also have to deal with corrosion,

which is a big field for materials engineers,

and you can even take elective classes on this in college.

Corrosion is destructive to metal,

so any pipes that carry some fluid will be subject to corrosion and need to be designed properly.

Whether it's pipes that carry water to and from our houses,

ones for oil, ones in our cars, and so on.

Or various marine technologies like submarines need to be designed not to corrode from all the interaction with saltwater.

Planes also need to account for this, and there's many more.

And different environments these are subject to,

like fresh water, salt water,

oil, etc., cause for different types of considerations when designing them.

Materials engineers need to take preventive measures to pick the right material to account for all this.

You could work on biomaterials,

which is something biomedical engineers take classes on as well.

But biomaterials are used for constructing artificial organs or to replace bone or tissue,

and these materials need to interact well with the human body and not cause harm.

For example, there are hydrogels that are needed to repair damaged heart tissues.

This incorporates biology and is something you could take an elective class on as well,

or you could see in grad school if it interests you.

You could work on making superconductors,

which are materials that have no resistance to electron flow,

like no heat or other form of energy is given off,

unlike your electronics which get hot as you use them.

And superconductors can be used for high speed digital circuits,

particle detectors, trains that use magnetic levitation and don't make contact with the ground, and so on.

They can also work on materials processing and manufacturing.

Materials engineering isn't just about analyzing properties of materials and how to use them,

but also better ways to manufacture these materials,

like with the fabrication of semiconductors that are used in our electronics.

Electrical engineers may do circuit analysis with these,

but how those components are made is done by other types of engineers, including materials.

Or you could work on the study of carefully rearranging atoms and molecules to form new structures that have better mechanical,

electrical, and magnetic properties for a material.

This is also known as nanotechnology.

The way that atoms are arranged are what gives the materials a lot of their properties.

It's why some things break when we drop them,

and why other things stretch when we pull on them.

If we can manipulate the arrangement of atoms,

then we can change the object's properties and how it behaves.

We can use this to create solar panels that can absorb energy much better,

all the way to making glasses that won't break when being dropped,

but there are so many more applications.

Materials engineers could make clothes that don't smell bad after use,

tires that grip the road better,

stronger tennis rackets, and the list goes on.

100

But now let's see what you can expect in college and kind of zoom in a little more on these materials.

101

So you're going to cover the four main classes of materials which are metals,

102

ceramics, polymers or plastics, and composites.

103

And although you learn a lot about everything,

104

there's a big focus on metals.

105

Now when it comes to all these materials,

106

big things we care about that you'll learn are the mechanical properties,

107

electrical properties, thermal properties, as well as the atomic structures.

108

Mechanical properties include hardness, ductility,

109

or an object's ability to deform when being pulled,

110

brittleness, where a material is brittle if you pull on it and it breaks without much deformation.

111

So if you have a material and you pull it,

112

eventually it will break.

113

If it's brittle, it will just snap.

114

Glass would be an example of this.

115

But if the material is ductile,

116

it will actually be elongated and deformed before totally snapping,

117

and certain types of steel would be an example of this.

118

In school, you're going to learn how to analyze certain graphs,

119

which have stress or force over area,

120

versus deformation or strain, like how far it's been stretched.

121

Then they'll give you some curve,

122

and you have to understand it.

123

This shows that if you pull an object very hard,

124

it only stretches a little.

125

So you know this is a stiff material,

126

versus a more flexible one,

127

which might look like this,

128

like for a rubber band.

129

And there'd be more to these curves you'd have to understand,

130

like its fracture point, ultimate strength,

131

what the slope of that initial line means,

132

and so on that can tell you more things like how brittle it is, and so on.

133

And every material will have a different stress-strain curve.

134

Nothing you have to worry about now,

135

but realize this is something that you'd learn.

136

And there's more mechanical properties,

137

but you get the idea.

138

Then you'll learn electrical properties,

139

like how well materials conduct electricity.

140

Thermal properties would, of course,

141

be how well heat can flow throughout an object.

142

You'll learn the atomic structures and bonding within these materials,

143

which is very important because sometimes those structures allow us to determine a material's properties.

144

For example, take graphite versus diamond.

145

Graphite is relatively soft while diamond is extremely hard,

146

yet both are made out of carbon.

147

This difference in mechanical properties comes from the way the atoms are arranged in these materials.

148

And there's more properties like magnetic properties and optical properties,

149

but this is the general idea.

150

So now like I said,

151

you go over the four main classes of materials,

152

and everything you just saw you will apply to all of these.

153

But a big one you go over is metal.

154

The main metals you go into include aluminum,

155

steel, stainless steel, titanium, copper, and so on.

156

One important topic dealing with metals you'll learn is heat treating,

157

which I'm going to explain a little so you can see its applications.

158

You're going to learn how to analyze a graph that has temperature versus time.

159

The temperature may go up to something like 800 degrees Celsius and down to let's say 100.

160

And let's say this is for something like steel,

161

which would be solid at all of these temperatures,

162

because again you don't really go into liquids or gases.

163

And the time may go from one second to something like a hundred thousand seconds or about 28 hours.

164

Then on the graph you'd be given something like this.

165

Don't even worry about what these are right now,

166

just realize these are the different transformations the material can go through.

167

Different materials have different looking graphs,

168

just like this red and green curve actually represent two different steels.

169

So let's say we heat up steel to about 800 degrees Celsius and start there.

170

Then we cool it to 100 degrees Celsius in one second, so very quickly.

171

That curve, or line in this case,

172

tells us which transformations this material goes through during cooling.

173

See how it goes through those regions with an M?

174

This goes through different transformations than if we slowly cooled it to the same temperature over the course of about a day.

175

So what does this do?

176

Well, if it's cooled very quickly like that first line,

177

that might yield a very hard but brittle material.

178

If you cool the material slower,

179

it may yield a slightly softer material,

180

but that is much tougher and doesn't break easily.

181

It's all the same material,

182

but we can achieve different mechanical properties just by cooling it differently.

183

Now moving on, you may do projects or reports on basic objects,

184

but go into depth on the material beyond what you may know.

185

These projects can be for anything,

186

but since we are on the topic of metals,

187

at one school students did a project on an ice cream scooper.

188

Seems simple, but what you may not know is that there is heat conducting fluid within the scooper.

189

This is designed to transfer the heat from your hand to the metal of the scooper,

190

and this warms the metal so that when you scoop the ice cream,

191

it kind of melts the ice cream,

192

making it a little easier for you to scoop,

193

as well as making it so that the ice cream does not stick to the metal.

194

Also, you can't read the words on the box in this image,

195

but on it it says new aluminum alloy that helps resist corrosion.

196

So hopefully you're seeing how the materials used in nearly everything

197

down to a simple ice cream scooper are optimized by the designers and how corrosion is a huge field as well.

198

Now I want to skip to composites.

199

This is something you may take an entire class on in undergrad.

200

Composites are made up of at least two different materials from the other three categories.

201

These are crucial because many technologies of today require materials with certain properties that cannot be met with normal metals,

202

ceramics, and polymers.

203

For example, when it comes to aircrafts,

204

we are trying to find materials that are strong,

205

stiff, and have low densities and more,

206

which is a tough combination of properties to achieve.

207

Often strong materials are also dense as an example.

208

So engineers are trying to design and find materials that can provide the properties we want to achieve,

209

which is where composites can come in.

210

So you're gonna learn about these mechanical properties,

211

look at stress strain curves of fiber reinforced composites as a random example,

212

methods of manufacturing composites, and so on.

213

Now I'm really not gonna cover ceramics and polymers in any detail,

214

but if you wanna know some basic examples,

215

Ceramics might be like a china cup,

216

a brick, or a dining glass.

217

And polymers or plastics might include a bicycle helmet,

218

pool balls, dice, and so on.

219

Now these are very basic examples,

220

but in school you cover more advanced materials that have engineering applications,

221

like silicon carbide that can be used to create very hard ceramics

222

which can be used for car breaks all the way to bulletproof vests.

223

Also note that there are many materials that we've all heard of,

224

but there are way more that you probably haven't heard of.

225

These are just a few out of hundreds that were just in an intro textbook on materials engineering.

226

No, you don't have to memorize all of these,

227

but this is a challenge with materials engineering

228

because of the sheer amount of materials out there that all have their different properties.

229

Now just briefly, when it comes to labs,

230

the equipment you can expect to see would be like microscopes,

231

tensile testers, hardness testers, and things like that.

232

A lab you might do is cool a material very rapidly,

233

then do tensile testing on it.

234

You'll use a machine that pulls the object in opposite directions,

235

which is what tensile stress is,

236

and you'll notice the material is very brittle like we saw earlier.

237

You'll use microscopes to look at the microstructures of various materials,

238

which is very important.

239

Like I said, you'll learn what these mean and how much they can tell you about a material.

240

I said that they can reveal material properties,

241

but they can even reveal how the object was made like with heat treating and how fast it was cooled.

242

For those wondering how much math you see during college,

243

there is math and calculus but it's not the majority of the curriculum.

244

For example in a kinetics class which you will take,

245

one thing you'll learn is diffusion and how atoms move throughout a material.

246

So you may have a high concentration of let's say carbon.

247

So to represent how the concentration changes over time you would have to use calculus

248

because the rate that that concentration is changing at is not constant.

249

Or remember that stress-strain curve?

250

Well the area under it is the energy absorbed and for those who have taken calculus you know this involves an integral.

251

So you see there is calculus and definitely math like algebra and linear algebra that I didn't mention,

252

but it's definitely not as much calc and higher level math as an electrical,

253

mechanical, or aerospace engineer might see.

254

Then as you can see there's also a lot of chemistry which you will learn within your materials engineering classes.

255

So if you struggle with math,

256

you should expect it in this major and be ready for it,

257

but you should also be able to handle it.

258

Overall, materials engineering covers a wide range of sectors and there are still many challenges that we face,

259

and materials engineers are doing research to overcome these challenges.

260

Whether it be to reduce the weight of cars and aircrafts,

261

reduce environmental pollutants in the production and fabrication of various materials,

262

or finding better materials for fuel cells to improve their efficiency.

263

Aerospace, mechanical, and civil engineers are just a few examples of majors

264

that also learn about materials and material properties in their curriculum,

265

but as you can see,

266

materials engineers dive much deeper.

267

And lastly, while there is a distinction that can be made between materials science

268

and materials engineering and how we categorize and define them,

269

at least in terms of undergrad,

270

at many schools it will just be called one or the other,

271

and you will likely be in the College of Engineering if you go into this major.

272

If you liked this video don't forget to comment,

273

like, and subscribe and I'll see you all next time.

TRENDING

Что такое техника Shadowing?

Shadowing — это научно обоснованная техника изучения языка, изначально разработанная для подготовки профессиональных переводчиков и популяризированная полиглотом доктором Александром Аргуэльесом. Метод прост, но эффективен: вы слушаете аудио на английском от носителей языка и немедленно повторяете вслух — как тень, следующая за говорящим с задержкой в 1–2 секунды. В отличие от пассивного прослушивания или грамматических упражнений, Shadowing заставляет мозг и мышцы рта одновременно обрабатывать и воспроизводить реальные речевые паттерны. Исследования показывают, что это значительно улучшает точность произношения, интонацию, ритм, связную речь, понимание на слух и беглость речи — что делает его одним из самых эффективных методов для подготовки к IELTS Speaking и реального общения на английском.

☕ Угостите нас кофе

ShadowingEnglish остаётся 100% бесплатным благодаря вашей поддержке. Стоимость серверов и ИИ высока — ваш кофе поддерживает нас! 🙏

Пожертвовать через PayPal

ShadowingEnglish.com – Практика Shadowing английского

Практика Shadowing: What is Materials Engineering? - Изучайте разговорный английский с YouTube

Популярные

Зачем практиковать разговорную речь с этим видео?

Грамматика и выражения в контексте

Распространенные ловушки произношения

Что такое техника Shadowing?

Практика Shadowing: What is Materials Engineering? - Изучайте разговорный английский с YouTube

Скачать приложение

Зачем практиковать разговорную речь с этим видео?

Грамматика и выражения в контексте

Распространенные ловушки произношения

Что такое техника Shadowing?