Mechanical properties crack-free

Sintered sihcon carbide retains its strength at elevated temperatures and shows excellent time-dependent properties such as creep and slow crack growth resistance. Reaction-bonded SiC, because of the presence of free sihcon in its microstmcture, exhibits slightly inferior elevated temperature properties as compared to sintered sihcon carbide. Table 2 (11,43) and Table 3 (44) show selected mechanical properties of sihcon carbide at room and elevated temperatures. 

The crack-free coated alumina specimens were subjected to a diffusion bonding (DB) procedure, described above. The parameters of the process were same as for non-graded specimens. After the bonding to IN-738 superalloy the joints were examined by their appearance and microstructure. For some specimens it was found that good, crack-free microstructure does not guaranteed high mechanical properties, in particular at elevated temperatures under external mechanical load. 

PSF/PET blends show a dispersed morphology. The combination of crystalline PET and amorphous polysulfone provides chemical resistance and warp-free properties. The amount of crystalline polymer is varied to meet requirements in thermal properties and the level of reinforcement is varied to tailor the modulus. The blends have electrical and mechanical properties similar to PET but only a third of its shrinkage and warpage. Also, stress crack resistance to common solvents is improved. Similarly, the service T is upgraded compared to PET. The blends are formed by injection molding and extrusion. 

In this work, crack-free, dense (up to 92% theoretical density), amorphous SiAlOC ceramic components with good mechanical properties have been obtained at low temperature (T = 1000°C) by direct pyrolysis of pre-ceramic green bodies. 

Grinding operation is one of the most effective methods used for hig smoothness machining of fine ceramics. It is difficult, however, to achieve crack-free high smoothness surfaces by ductile-mode grinding because of their mechanical properties of high brittleness [1]. Therefore, it is necessary... 

For good mechanical properties of alumina, this ceramic must be largely flaw-free and must have a high density these properties would make it useful as a structural material and for various industrial applications. The presence of cracks... 

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