Applications (PSZ,TZP,ZTA)

Question 1

What is the thermal shock resistance for these parts?

Answer 1

~ relative to PSZ/TZP/ZTA, Si3N4 has a combination of low CTE and relatively high thermal conductivity, giving it excellent thermal shock resistance

Question 2

What is the fracture strength enhancement for these parts?

Answer 2

~ the fracture strength enhancement of Si3N4 does not decay until substantially higher temperatures than PSZ/TZP/ZTA, though it does not start as high (room temp)

Question 3

Which has the greatest fracture toughening at room temp?

Answer 3

~ SSN, as it has the most glassy grain boundary phase

~ however, SSN suffers from creep at lower elevated temps than HPSN and HIPSN, and its earlier decrease in flexural strength with increasing temp is related to this viscous deformation (creep cavitation)

Question 4

Which does not creep?

Answer 4

~ RBSN does not have a glassy GB phase, thus it does not creep

~ RBSN’s flexural strength is unchanged with increasing temp

Question 5

Why is Si3N4 the preferred ceramic/

Answer 5

~ very light
~ low CTE
~ flexural strength is consistent with temp
~ high thermal conductivity

Question 6

Cutting tools

Answer 6

~ Si3N4 is a superior machining tool for grey cast iron

~ up to 1000C at the cutting edge: Si3N4 has the hot hardness, thermal shock resistance, and chemical inertness for the application

Question 7

Engine components

Answer 7

~ four stroke reciprocating engine

~ the original imputus for the development of Si3N4 was for an all-ceramic enginer that could operate more efficiently at higher temp

Question 8

Frequency converters

Answer 8

~ for high speed electric motors: their fast switching electronics cause electric current damage in standard bearings

~ used in formula one race cars for their marginal lubrication requirements, heavy load capabilities, and high speeds

Question 9

Pumps and compressors

Answer 9

~ used since they tolerate marginal lubrication conditions and fluids with lower viscosity than lubrication oil, like refrigerants

Question 10

More

Answer 10

~ wind turbine generators (electrical resistance provides electrical isolation from lightning strikes

~ railway traction motors (electrical trains)

Question 11

More

Answer 11

~ wind turbine generators (electrical resistance provides electrical isolation from lightning strikes

~ railway traction motors (electrical trains)