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SHAPE MEMORY ALLOYS (SMA)
Read the text and choose the best heading (A, B, C) to each part:
A. Applications of Shape Memory Alloys.
B. What are Shape Memory Alloys?
C. Advantages and Disadvantages of Shape Memory Alloys
I. _____________________________
Shape memory alloys (SMA's) are metals, which exhibit two very unique properties, pseudo-elasticity, and the shape memory effect. Arne Olander first observed these unusual properties in 1938, but not until the 1960's were any serious researches made in the field of shape memory alloys. The most effective and widely used alloys include NiTi (Nickel - Titanium), CuZnAl, and CuAlNi.
II. ____________________________
The unusual properties mentioned above are being applied to a wide variety of applications in a number of different fields. The shape memory effect is currently being implemented in:
- coffee pots
- the space shuttle
- thermostats
- hydraulic fittings (for airplanes)
Some examples of applications in which pseudo-elasticity is used are:
- eyeglass frames
- bra underwear
- medical tools
- cellular phone antennae
- orthodontic arches
III. ___________________________
Some of the main advantages of shape memory alloys include:
- bio-compatibility
- diverse fields of application
- good mechanical properties (strong, corrosion resistant)
There are still some difficulties with shape memory alloys that must be overcome before they can be used up to their full potential. These alloys are still relatively expensive to manufacture and machine compared to other materials such as steel and aluminium. Most SMA's have poor fatigue properties; this means that while under the same loading conditions (i.e. twisting, bending, compressing) a steel component may survive for more than one hundred times more cycles than a SMA-element.
Answer the following questions:
1. How many unique properties have the SMAs got?
2. What are they?
3. How long is the history of SMAs?
4. What are the most famous alloys?
5. What property of SMAs is mostly used in Medicine?
6. What are the advantages of the SMAs?
7. What are the disadvantages of the SMAs?
Part III
(… адрес интернет-странички с видеороликами…)
SHAPE MEMORY EFFECT
(00:26)
PRE-LISTENING
1. Do you know the following words:
“wire”, “ice”, “to heat”, “to cool”, “hot”, “flame”, “soft”, “deformable”?
WHILE-LISTENING
Watch the video and answer the following questions:
2. What is the wire made of?
3. Why is it called “smart”?
4. How many stages can you divide the process on the video into?
5. Complete the following sentences about each stage of the process on the video:
a) We __________ the wire with __________.
b) The wire __________ soft and easily __________ .
c) We heat the __________ with a __________ .
d) The __________ turns to its __________ shape.
POST-LISTENING
6. Think of when and where this wire can be used?
2. SMART __________
(00:33)
Watch the track and answer the questions.
1. What type of “smart” material is it about? Complete the heading.
2. Why is it called “smart”?
3. What do you need to do to change the colour of the glass?
4. How can people use this “smart” glass?
FASHION METAMORPHOSIS
(02:30) – video, inscriptions
PRE- LISTENING
Think on the following:
1. What do we mean when we think about fashion?
2. What connection may there be between fashion and smart materials? How can smart materials be used in fashion?
WHILE- LISTENING
3. Watch the video, read and understand the inscriptions.
POST- LISTENING
4. Which do you think is the most useful usage of smart materials?
5. Which sphere would you invest to organize future researches and why?