Sintering incomplete

Ti. This leads to an increase in the concentration of the majority (electron) carriers and therefore the conductivity. The photocurrent densities sometimes vary due to incomplete dissolution as well as large dopant concentrations [10]. Raising the sintering temperature of Ti02 Nb to 1350°C and maintaining the doping concentration ND/[Ti j in the range of 0.05 at%, leads to an increase in photocurrent by a factor three [11]. 

Reported volume resistivities for printed patterns formed from commercial silver-based inks are higher than that of bulk silver. This occurrence reflects the fact that sintered ink patterns contain non-ideal defects such as incomplete particle-to-particle contact, incomplete sintering between contacting particles, residual porosity, and the presence of non-conductive additives. The morphology and extent of void formation in two representative sintered silver nanoparticle inkjet inks are illustrated in Fig. 1. 

Many factors are to be taken into account to obtain reliable results. The powdered solid salt B may sinter before opening the funnel, causing incomplete mixing. The salt B should have suitable physico-chemical properties, such as vapor pressure, chemical reactivity with respect to the funnel and the container, etc., to remain in the funnel during thermal stabilization and to fall down completely when the funnel is open. 

Pressure sintering. Sometimes, hardmetals exhibit residual porosity (A and B type), which can occur for several reasons. Since the 1970s pressure sintering (HIP-ing) has been applied to remove this porosity. For that purpose, the sintered specimens are loaded in a HIP-ing device and heated again under Ar or He pressure of 50-150 MPa (temperatures and commonly 25-50 °C below the vacuum sintering temperature). Hence any residual porosity can be removed. Exceptions are gas porosities, which either can occur due to incomplete outgassing of the carbon monoxide, or due to the presence of impurities. 

Figure 10.18 SEM micrographs of the surface of an incompletely sintered PTFE tubing at magnifications of (a) lO.OOOX, and (b) 20,000X. (Courtesy of DuPont Fluoroplastics.)...

Incomplete resin sintering Short heating cycle Low mold temperature Slow heat transfer due to excessive wall thickness of the mold Improper oven air flow... 

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