Data from experiments section 2 line fits from theoretical analysis section 4.
													
																	Stress strain curve for ceramics. 
									
	
		
	
																	It was found that they behaved as elastic materials. 
																	Quasi ductile ceramics 523 indentation stress strain po a r data are plotted in fig. 
																	The electric strain gauge was used to study the deformation of several types of ceramic materials under stress. 
																	For brittle ceramics a three point bending apparatus shown in the figure below is used determine the stress strain behavior and the measurement results are used to calculate an equivalent modulus of elasticity. 
															
													
									
	
		
	
																	With a very short elastic region but highly capable of supporting huge stresses. 
																	In engineering and materials science a stress strain curve for a material gives the relationship between stress and strain it is obtained by gradually applying load to a test coupon and measuring the deformation from which the stress and strain can be determined see tensile testing these curves reveal many of the properties of a material such as the young s modulus the yield strength. 
																	And finally analogous to ceramics are the stiff fibers and rigid plastics. 
																	1 metals al alloy stress strain curve. 
															
													
									
	
		
	
																	2 stress strain curve for ceramics. 
																	5 for each of the glass ceramic. 
																	The hard fired materials exhibit straight line deformation to failure while the softer fired have a proportional elastic limit beyond which the stress strain curve deviates. 
																	Indentation stress strain curves for base glass and glass ceramics heat treated at specified temperatures for 4 h.