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魔法金属-形状记忆合金的原理 – 译学馆
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魔法金属-形状记忆合金的原理

Magical metals, how shape memory alloys work - Ainissa Ramirez

今天我们来讨论超自然材料
Today we’re talking about weird materials
我们将其用于太空,机器人以及你们的口里
that we use in space, in robots and in your mouth.
我现在谈一谈形状记忆合金
I’m talking about shape memory alloys.
正如它的名字一样
Like the name says,
这些金属可以记住不同的形状
these are metals that remember different shapes.
为了明白这些金属如何实现这一点
To understand how these metals work,
我们必须谈谈原子和组织
we’ve got to talk about atoms and organizing.
首先谈谈原子
Let’s talk about atoms first.
原子是你们用眼睛无法看到的极小的物质
Atoms are tiny bits of matter that you cannot see with your eye
然而它们能组成我们世界上的任何东西
yet they make up everything in our world,
从你们坐的椅子到你们的手机
from the chair that you’re sitting on to your cell phone.
原子也有令人惊讶的运动轨迹
Atoms have some surprising ways of behaving too.
我们简单说说吧!
We’ll talk about that shortly.
原子有多大?
Now, how big is an atom?
好的 想象从你的头上拔掉一根头发
Well, imagine pulling one of your hairs out of your head
将它削减100000倍
and whittling it like a stick 100,000 times.
其中的一个修面可能是一个原子的宽
One of those shavings would be the width of an atom.
它们是那么小
They’re that small.
现在谈谈原子和组织
Now let’s talk about atoms and organizing.
你也许不知道这些 但是原子安排自己的方式
You may not know this, but atoms arrange themselves
类似于人类安排自己的方式
similar to the way we humans arrange ourselves.
有时候它们一排排坐着
Sometimes they sit in rows, like we do
好像我们坐在巴士或者飞机上
on a bus or an airplane.
我们可以称之为排座位的阶段
We call that seating arrangement a phase.
其他时候他们都相互斜坐着
Other times they sit diagonal from each other,
类似于电影院或者运动馆里的座位
sort of like seats in a movie theater or sports stadium.
接下来是另一阶段
This is another phase.
当原子从一个座位移动到另一个座位
When atoms move from one seating to another
我们称之为相变阶段
this is called a phase change.
相变就一直在我们身边
Phase changes are all around us.
你也许知道水的几个阶段
You may already know about water’s phases:
固体 液体 气体
solid, liquid and gas.
其他许多金属也同样有这样的阶段
Many other materials have phases like that too.
一些金属有几个固定的阶段
Some of them have several solid phases.
好了 回到一些我们提到过的记忆型合金
OK. Back to those shape memory alloys we mentioned before.
当我们说到合金记住它们的不同的形状
When we say that the metals remember their different shapes,
我们所说的事实是它们记住了不同的排位
what we’re really saying is they remember different seating arrangements
在原子里的 当原子重新排列
of atoms. When the atoms rearrange,
合金会从一个形状变到其他形状
the metal moves from one shape to another.
让我们来看看一个阶段变化的运转
Let’s look at a phase change in action.
我这里有一个合金写着由镍和钛组成的
Here I have a metal wire that is made out of nickel and titanium.
这个合金是一个阶段性合金
This metal wire is a shape memory alloy,
和我打算使它转换在它自己不同的阶段
and I’m going to make it switch between its different shapes
用点火进行高温燃烧
using heat from a lighter.
看这个
Watch this.
我打算换了我手上的电线
I’m going to wrap this wire around my finger
然后加热它
and then heat it.
令人吃惊!
Amazing!
当我燃烧时电线变直了
That wire returns to a straight line, when I heat it.
让我们再试一次
Let’s try that again.
我打算把它缠绕在我的手指上燃烧
I’m going to wrap it around my finger, and heat it.
好!这仍旧让人吃惊
Yep, that’s still amazing.
不仅仅是它使人吃惊 这条电线
Not only is it amazing, this is weird,
因为普通的合金做不到
because metals generally don’t do that.
这是一张剪纸 当我燃烧了它 我什么也没有留下
Here’s a paper clip. When I heat it, I get nothing.
当它变热我们就看到了记忆金属变化的阶段
What we’re seeing is the shape memory wire changing phases when it gets hot.
当电线变冷原子就会呈现出斜线的布置
When the wire is cold, atoms are in a diagonal arrangement,
就像我们之前说的电影院的位置
like the movie theater seating, we talked about before.
我们称它为单斜晶体的位置
We call this a monoclinic arrangement,
科学家们称它为马氏体形状
and scientists will call this phase martensite.
当我加热电线
When I heated up the wire,
原子就会回到塔器就像飞机回到位置
the atoms moved into columns like airplane seating.
这是一个立方的安排
This is a cubic arrangement.
科学家们称它为奥氏体
Scientists will call this phase austenite.
所以当我们加热时原子会跑到斜对面无缝
So when we added the heat, the atoms shifted positions seamlessly,
它们会一直这样做
and they’ll do this forever.
他们有这么协调的动作 就像是不知疲倦的行进中的部队
They have this coordinated motion, just like members of a tireless marching band.
每个个体做出很小的变化 但是所有这些小的组合在一起
Each makes a small shift, but all together those small shifts
就成了很不一样的图案
create a totally different pattern.
所以这些很有意思的 但是我们会把这样的金属用在哪里呢?
So that’s pretty cool, but where do we use these materials?
这样 如果你今晚抬头仰望天空
Well, if you look in the sky tonight,
这种记忆合金用在火星上
shape memory alloys are at work –
他们被用来移动漫步者上边的控制面板
on Mars. They’re used to move panels on the Mars rover,
因此这种面板会适应环境
so that it can study the environment.
就像当金属被加热后会变直一样
Like our metal straightened when it was heated,
这承托面板的金属被电热加热后会变形
the metals holding the panels will move when electrically heated.
当我们停止加热时
When we stop heating the shape memory metal,
这面板形状会恢复 类似于小树苗长出来一样的
the panel will return back, due to an opposing spring.
回到地球上来 形状记忆金属被用来疏通被阻碍的动脉
Back on Earth, shape memory alloys are used to open up clogged arteries
像支架一样的 那种可折叠的弹簧一样
as stents, which are small collapsible springs
能够开通通路
that force open passages.
形状记忆合金也被用来在机器人的行动上
Shape memory alloys are also used to move robots,
玩具蝴蝶 背带的锯齿 还有任何合适的地方
toy butterflies, teeth in braces, and for a perfect fit every time,
形状记忆电线被用在胸罩内衣里
shape memory wires are used as underwires in bras.
现在你知道维多利亚的秘密了吧
Now you know Victoria’s secret.
在烘干机里烘干胸罩 它就会恢复成原来的样子 像新的一样
By popping a bra into the dryer, it’ll be brand new every time.
所以 不论在火星还是在你嘴中 小原子的运动
So whether it’s on Mars or in your mouth, small atomic movements
可以创造出巨大的变化
can create huge changes,
同时 理解原子的运动形式
and understanding the way atoms behave
可以让我们制造出使世界变得更美好的新金属
allows us to make materials that make our world a better place.

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