Segregation measurement of powder injection molding feedstock using thermogravimetric analysis, pycnometer density and differential scanning calorimetry techniques

Powder distribution on powder injection moulding of ceramic green compacts using thermogravimetric analysis and differential scanning calorimetry

“…Inhomogeneous distribution between powder and binder in green compacts are hard to identify and this uneven distribution causes thermal expansion to vary with position and direction [12]. The separation of powder and binder can be evaluated by measuring the density, specific heat, thermal conductivity, heat of fusion, weight loss after binder burnout, electrical conductivity, rheology and microscopic examination [13][14][15][16][17]. These methods measure the solid loading which is the equivalent to the volume fraction of powder in the specimen.…”

“…Therefore, powder distribution analysis method that measures the powder content within a green body is crucial to the development works of PIM. Based on the literatures, several methods have studied the use of X-ray computed tomography, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), pycnometer, Archimedes' principle for powder distribution analysis of ceramic and metal green bodies [17,[20][21][22][23].…”

“…Authors have shown that the TGA and DSC can be used to determine binder content of powder-binder mixtures, the homogeneity of metal-powdered feedstock [17]. The sensitivity of using the TGA, DSC and pycnometer to measure the solid volume of metal-powdered feedstock was compared and it showed that these methods can be used to measure the segregation effects within the feedstock.…”

“…The sensitivity of using the TGA, DSC and pycnometer to measure the solid volume of metal-powdered feedstock was compared and it showed that these methods can be used to measure the segregation effects within the feedstock. TGA method can also be used to detect the point to point distribution and segregation of metal powder in green parts as demonstrated [17]. The additional benefits of using the TGA and DSC is that they can be used to determine other process parameters useful for the debinding and injection moulding process.…”

“…ACCEPTED MANUSCRIPT 3 thermal debinding. The thermal properties such as specific heat and heat of fusion of metal-powdered feedstock have been demonstrated to be determined by the volume fraction of powder and binder [17,26]. Using the DSC, softening points, heat of fusion, specific heat capacity of the binders and feedstock can be determined, and this can be used to identified suitable compounding and moulding temperatures [1].…”