Microstructures exercises 1.01

Question 1

How can you differentiate a macro structure with a microstructure?

Answer 1

macro structure you can see them with the naked eye (without tools), micro only with microscope

Question 2

Give 3 examples in which the materials properties can be influenced by variation of the macro structure

Answer 2

-Increasing of heat insulation of building materials by increasing their porosity
-Increasing the tensile strength and stiffness of polymers by addition of fibers or filler
-Influence of concrete properties by additions certain concrete aggregates

Question 3

Define the term phase

Answer 3

area with same composition and/or microstructure

Question 4

Name some examples of single-phase materials

Answer 4

bitumen, many polymers, some metals, alloys, etc..

Question 5

Name some examples of multi-phase materials

Answer 5

(most building materials). concrete, wood, asphalt, composites, etc.

Question 6

What’s homogeneity? give 3 examples.

Answer 6

equal constitution in any partition, uniform and constant structure.
metals, polymers and glass

Question 7

What’s heterogeneity? give 3 examples.

Answer 7

materials with different areas, varying in structure and composition.
natural stone, concrete and wood.

Question 8

What’s an anisotropic material? give examples.

Answer 8

properties depend on spatial direction (mechanical, optical, physical)
wood, natural stone

Question 9

What’s an isotropic material? give examples.

Answer 9

properties do not depend on spatial direction (always equal)
polycrystalline materials, silicate materials and ceramics