07 Ceramics and Glasses Free Online FlashCards

How do strong bonds affect many ceramics?

Strong ionic and covalent bonds help many ceramics resist heat, wear, and chemical attack, but also make atomic rearrangement difficult.

Why can a small flaw cause ceramic failure?

Ceramics are brittle because they undergo little plastic deformation before fracture; cracks and pores can concentrate stress and trigger failure.

What happens during ceramic sintering?

Sintering heats shaped ceramic powder so particles bond and pores shrink, developing much of the component’s final density, strength, and microstructure.

Why is borosilicate glass used for laboratory glassware and cookware?

Borosilicate glass is used for laboratory glassware and cookware, where resistance to thermal change and chemical attack is useful.

What defines a crystalline ceramic?

A crystalline ceramic has atoms or ions arranged in an ordered, repeating structure.

What makes glass amorphous?

Glass is an amorphous solid: its atoms lack long-range repeating order, although they retain local bonding patterns.

What structure forms the network in silica glass?

In silica glass, silicon and oxygen form a connected network of SiO₄ tetrahedra.

How can other oxides affect a glass network?

Other oxides can modify or stabilize the silica network, changing glass properties such as softening temperature and workability.

Which loading do ceramics usually tolerate better: compression or tension?

Ceramics usually tolerate compression better than tension.

What microstructural features can improve ceramic strength?

Fine, uniform grains and low porosity can improve ceramic strength.

How does glass soften when heated?

Unlike a crystalline material with a sharp melting point, glass softens gradually over a temperature range, so it can be shaped while hot.

What is the purpose of glass annealing?

Annealing uses controlled heating and cooling to reduce stresses left in glass after forming.