Microstructural observation is one of the most important skills for materials scientists and engineers
because it is the key to understanding the behavior of materials. In addition to the type of bonding and
atomic arrangement, microstructure can affect various properties of materials. For example, the presence
of pores (or porosity) can reduce mechanical strength, hardness, thermal and electrical conductivity of
most materials greatly. Many properties of a crystalline solid could also be very different if the grain size
has been changed. In addition, more observable microstructure such as crystal shape, particle orientation,
or phase content is valuable information for controlling or improving materials’ properties.