Some of these examples are discussed in detail elsewhere in the text here we are concerned with why the sintering process is used.
Why do we use translucent polycrystalline alumina rather than single-crystal alumina ,which is transparent,in alumina lamp envelops ? Why use alumina and not yttria for this application : the yttria would allow the lamp to operate at higher temperatures producing a whiter light ? The answer in both cases in the coat; bothcases is the coat ; both would be tecnhologically possible. The alumina envelops is particularly interesing because of the use of MgO to limit grain growth.
Templated growth of material like BaTiO3 presents an attractive route to producing a textured ceramic. Templated grain growth of alumina was discussed above. The principle involved here is the use of a seed to initiate exagerated grian growth.
Nanomaterial are very reactive,which means that we can usually sinter nanoparticles at temperatures that are much lower than for conventional powder. However ,they are also reactive even when you do not want them to be. In this case we can coat the nanoparticles to induce a repulsion or simply to physically prevent them from jioning.
Material are bonded together during packaging in IC fabrication using several different technologies,such as anodic bonding, Si-fusion bonding,surface-activeed bonding, are intermediate thin-film bonding.In each scheme, heat in applied to sinter two surface together. Diffusion bonding of Si wafers may require vary little diffusion if the wafers are narely atomically flat. We can improve the bonding process and is used to join Si to SiO2.
Millefore paperweights are essentially formed using sintering. The individual canes of glass are bonded together in a glass matrix : the essentail point is that the canes do not melt.