TRUE/FALSE Flashcards
(27 cards)
During the drying process of ceramic products, there is a shrinkage of about 10-20% occuring
TRUE
Composites are formed by a matrix phase and a reinforcement phase. The reinforcement phase protects the matrix phase and distributes the load to the reinforcement phase
TRUE
In general, a metal (ex: steel) has a larger toughness than a ceramic material (ex: cement)
TRUE
The movement of dislocation is responsible for elastic deformation in ceramics
FALSE
Dislocation in PLASTIC
It is not recommende to use gypsum plaster for finishing outsite walls exposed to the environment
TRUE
The sequence of the following material is correctly ordered from the highest to the lowest thermal conductivity
1. Aluminium oxide
2. Copper
3. Polyethylene
TRUE
Sustainability is a system problem and must be tackle according to the 3P approach: Planet, People, Prosperity
TRUE
Wood is a sustainable material and has a great advantage of being mechanically resistant to compression and tension reaching a yield strength of 500MPa
FALSE
In ceramic materials, sintering occurs during firing at a temperature of about 3/4 of the melting temperature of the ceramic constituents
TRUE
Gypsum plaster is obtained from gypsum rock crashed and treated at 500C. Then the dried powder is mixed with some quartz powder to obtain the final plaster
FALSE
It is mixed with WATER
Glasses can be tempered to gain flexural strength
TRUE?
We need to build a house on a soil that has a high quantity of sulphates in it. For the foundations it is recommended to emply a concrete containing a cement with high content of blast furnace slag rather than a standard cement
TRUE
The sequence of the following material is correctly ordered from the highest to the lowest tensile strength
1. Silicone
2. Stainless steel
3. Tempered glass
TRUE
Stainless steel is an iron-carbon alloy (Fe-C) with the mandatory addition of at least 20% of Titanium
FALSE
It’s CHROMIUM not Titanium
For temperature higher than the glass transition temperature (T>Tg), glasses have a pure elastic behavior and it’s subjected to brittle fracture
FALSE
(T>Tg): VICIOUS BEHAVIOUR
(T<Tg): ELASTIC BEHAVIOUR
Thermosetting polymers dont have a glass transition temperature
FALSE
Speaking about polymers, what is the meaning of “PS”? It is a polymer:
a. Thermoplastic
b. Thermoset -
c. Partially crystalline
d. Obtained using only hydrogen and carbon atoms
a. FALSE (TP)
b. FALSE (TS)
c. FALSE
d. TRUE (PS: POLYSTYRENE)
Which are the main characteristics of metal?
a. Ductility
b. Brittleness
c. Electrical conductivity
d. Thermal conductivity
a. TRUE
b. TRUE
c. FALSE
d. FALSE
Stainless steels
a. Must have C > 12%
b. Are showing better corrosion resistance than CORTEN steel
c. Cannot be used for anti seismic application
d. Are showing bettter elongation than carbon steels
a. FALSE (depends on types)
b. TRUE
c. FALSE
d. TRUE (stainless: 45%; carbon: 25%)
What is strain hardening
a. A thermal treatment made at temperature higher than melting
b. A treatment to improve plastic deformation of a given steel
c. A process that changes microstructure to the material
d. A mechanical treatment to increase the strength of a metal
a. FALSE
b. TRUE
c. FALSE
d. TRUE
- Strain hardening is a phenomenon whereby a ductile metal becomes harder and stronger as it is plastically deformed. It is also called work hardening or cold work
- Strain hardening is often utilized commercially to enhance the mechanical properties of metals during fabrication procedures
The plastic deformation into a material
a. Occurs for materials which are breaking in a brittle way
b. Never occurs for metals and polymers
c. Is done to increase the properties of ceramics
d. Is due to movement of dislocations into the material
a. FALSE
b. FALSE (Metals have plastic deformation)
c. TRUE
d. FALSE
In the hot rolling of steels
a. The slabs are heated up to temperature of 2000C before the rolling
b. Thickness lower than 2mm can be reached
c. The final product is usually mechanically reinforced with polymer coating
d. Is a preferred technique to obtain stainless steel sheets
a. FALSE (1250C)
b. FALSE (30mm)
c. TRUE
d. FALSE (for steel in general)
LIME
a. Are divided into air or hydraulic
b. Provide the carbonation with a very fast reaction
c. When not properly hydrated cause cracks and defects in the finished wall
d. Can be reinforced with magnesium oxide to increase mechanical properties and firing times
a. TRUE
b. FALSE (it’s a slow process)
c. TRUE
d. FALSE
Accelerating admixtures in cements
a. Are used in hot weather conditions
b. Can lead to the corrosion of steels
c. Improve strength developments
d. Make use of thermoplastic polymers
a. FALSE (Cold weather)
b. FALSE (added for improving cement’s properties)
c. TRUE
d. FALSE
