Table 4.

Research on Powder Addition Reinforcement.

Authors	Materials		Methods	Dimensions & Testing Standards			Outcomes
	Base	Addition		Tensile	Flexural	Compressive
Masood and Song (2004) [68]	Nylon	Fe	Powder content of 40 vol% fine (<30 μm) and coarse (50–80 μm), and 30 vol% coarse.	Filament testing	-	-	Highest UTS, Tensile modulus, and tensile strain at break were 3.87 MPa, 54.52 MPa, and 16.82%, respectively at 30% Fe (Coarse).
Nikzad et al. (2011) [69]	ABS	Fe	Powder content of 5, 10, 20, 30, and 40 vol%	Not Standardized	-	-	Iron-filled ABS had characteristics of brittle and hard material with much lower elongation. Tensile strength drops significantly (25%) as a result of the addition of 10 vol% of iron powder
Karsli et al. (2013) [52]	ABS/PA6	CaCo3	Powder content of 5–30 wt%,	ISO 527	-	-	UTS increased by 15% with 5 wt% addition of CaCo3 powder and then decreased as the powder content increased. Elongation decreased from 220% to 62%
Perez et al. (2014) [51]	ABS	TiO2	Powder content of 5 wt%	ASTM D638	-	-	The UTS increased by 12.98% compared to pure ABS, but the strain decreased by 10%.
Weng et al. (2016) [71]	ABS	OMMT	Powder content of 1, 3, and 5 wt%	ASTM D638	ASTM D790	-	Tensile strength and elastic modulus increased by 43% and 200%, respectively, Flexural strength increased by 33.3%.
Osman and Atia (2018) [72]	ABS	RS	Powder content of 5, 10, and 15 wt%, variation of raster angle	ASTM D638	ASTM D790	-	UTS decreased as the RS content increased, then increased again until reaching maximum UTS at 15 wt% of RS content at a 0° raster angle. The tensile modulus decreased as the RS content increased. FS decreased as the RS content increased, then increased again until reaching maximum FS at 15 wt% of RS content at a 0° raster angle. The flexural modulus decreased as the RS content increased, and then increased again until reaching a maximum modulus at 15 wt% of RS content at a 0° raster angle.
Çanti and Aydin (2018) [67]	ABS	Al & ZrB2	Powder content of 1.5 wt%	ISO 527	ASTM D790	-	UTS increased by 0.3% and 12.6% with the addition of Al and ZrB2, respectively. The strain increased by 85% and 108% with the addition of ZrB2 and Al, respectively. FS decreased around by 5% with the addition of 1.5 wt% Al. FS increased by 8.7% with the addition of ZrB2. The deflection property improved by 3.7 and 26 percent with Al and ZrB2 addition, respectively.
Ecker et al. (2019) [73]	PLA	Wood	Powder content of 15 and 30 wt%	ASTM D638	-	-	UTS decreased as the wood powder content increased, whereas the water absorption increased as the wood powder content increased.
Sezer and Eren (2019) [74]	ABS	MWCNT	Powder content of 1, 3, 5, 7, and 10 wt%, variation of raster angle	ASTM D412	-	-	UTS was remarkably increased by 288% compared to pure ABS at 7 wt% of MWCNT at a 0°/90° criss-cross raster angle.
Walker et al. (2020) [70]	PLA	AgSMW (Silver sub-micron)	Powder content of 0.1, 1, and 10 wt%	ASTM D638	-	-	UTS and strain at break decreased moderately as the AgSMW content increased, whereas the tensile modulus did not chang significantly. However, the addition of 10 wt% of AgSMW significantly reduced bacteria growth by close to 50%.