Uniformity Differentiation Analysis of Powder Deposition Characteristics in Circular and Rectangular Shallow Dies Using Feed Shoe with Square Cross-Section

The inhomogeneity of the pressure distribution after completion of the filling process might create tablet and compact quality issues. Generating a uniform precompaction powder deposition into a die would minimize one source of tablet quality issues. This article determines the characteristics of the deposition process into a rectangular die and a circular shallow die, using a feed shoe with a square cross-section tube. A series of experiments were performed that determined the cumulative influence of particle size, die geometry, and feed shoe speed on uniformity of pressure distribution at the end of filling process. For uniformity comparison, the profiles of pressure distribution at the end of filling process were displayed as contour plots. Symmetry analysis, variance metrics, and uniformity analysis were implemented to quantify the deposition characteristics. Feed shoe speeds of 20 and 100 mm/s were used to fill the die. Due to their differing particle characteristics and importance, a pharmaceutical powder filler (microcrystalline cellulose-Avicel PH102) and a battery powder mixture (BPM) were used as test materials. The results showed that (1) contour plot was the most reliable method for evaluating uniformity deposition characteristics in dies; (2) based on contour plot analysis, BPM deposition at 100 mm/s feed shoe speed for circular shallow dies resulted in the most uniform pressure distribution among all, that is, 64% uniformity at ±20 dm (decimeter) resolution and 14.7% coefficient of variation (COV); (3) Avicel deposition at 20 mm/s feed shoe speed for circular dies had the least uniformity (46%); (4) rectangular dies generally had lower symmetry index (61%) in comparison with circular dies, which was attributed to sharp edges of rectangular die, that is, particles trapped in corners generated higher stresses inside the rectangular die versus circular die.     

Uniformity Differentiation Analysis. Part 1: Powder Deposition Characteristics in Rectangular Shallow Die Using Feed Shoe with Circular Cross Section

The process of die filling is a significant unit operation in many industries. Inhomogeneity of distribution such as in mass, bulk density, and pressure might cause many tablet and compact quality issues, such as lamination, capping, and distortion. No systematic investigations have been done to evaluate pressure distribution characteristics in dies with small aspect ratios (ratio of fill height to characteristic cross section dimension <0.5). In order to evaluate pressure distribution during filling of shallow dies, a circular cross section feed shoe was used at two speeds. The deposition characteristics of two powders with differing particle characteristics were studied in this research. The second-generation pressure deposition tester (PDT-II) was used to measure the two powders' pressure distribution characteristics. A battery powder mixture (BPM) and microcrystalline cellulose (Avicel PH102) were used to fill a rectangular shallow die 32 × 30 mm in dimension and 6.5 mm deep. Feed shoe speeds of 20 and 100 mm/s were used to fill the die. Symmetry analysis, variance metrics, Gini coefficient, and uniformity analysis were used to quantify the deposition characteristics. The results showed that (1) the contour plot was the most reliable method for measuring powder deposition characteristics; (2) the leeward and forward pressure distrbution comparisons generated a larger symmetry index than the front and back pressure distribution; (3) based on contour plot analysis, BPM at 100 mm/s feed shoe speed resulted in the most uniform pressure distribution (64% uniformity at +/?20 dm (decimeter) resolution) among all; (4) feed shoe speed greatly influenced pressure distribution uniformity inside the die; and (5) the high stress zone was mostly observed in forward and back regions inside the die.     

Powder Deposition in Three Parallel-Oriented Dies of Different Shapes

Uniformity of bulk density distribution during the die filling process is required to minimize quality problems, such as distortion and cracking, for powder compacts. Understanding the die filling process is necessary in ensuring a uniform powder deposition. The second-generation pressure deposition tester (PDT-II) was used to investigate the deposition process and final pressure distribution of powder filling in toroidal, cylindrical, and E-shaped dies. All tests were conducted using a spray-dried free-flowing granular powder. The results indicated that for toroidal dies: (1) the area around 0° orientation (the leeward end) had the highest pressure values (1186.7 to 2498.0 Pa), with the average pressure values of the remaining area 353.7–648.0 Pa; (2) the pressure distribution was symmetrical about the centerline parallel to the feed shoe movement direction; (3) the highest feed shoe speed (500 mm/s) led to the most nonuniform pressure distribution among the three speeds; (4) higher feed shoe speed did not always result in higher final pressure values; and (5) the right die tended to have higher final pressure values (215.0 to 2498.0 Pa) than the center die (95.4 to 2052.5 Pa). For E-shaped dies: (1) the final pressure values of the middle leg (308.9 to 760.7 Pa) were higher than those of the left and the right legs (148.9 to 530.3 Pa); (2) the area along the backside had the highest final pressure value (1054.6 to 1303.8 Pa); (3) the pressure distribution was symmetrical about the centerline parallel to the feed shoe movement direction; and (4) neither the center die nor the right die always had higher pressure values than the other one at all locations. Comparison between cylindrical and toroidal dies indicated that: (1) neither of the two die shapes (cylinder and toroid) led to consistently higher or lower final pressure values at all locations and (2) for all three feed shoe speeds, the toroidal die had higher average final pressure values in the 0° orientation.     

Microstructure of YSZ Coatings Deposited by PS-PVD Using 45 kW Shrouded Plasma Torch

In this study, a conventional 80 kW class plasma spraying system was used to produce yttria-stabilized-zirconia (YSZ) coatings by PS-PVD at a pressure of 100 Pa. A shroud was attached in the front of the plasma nozzle to restrain expansion of plasma jet. The torch was operated at an arc power of 45 kW and YSZ coatings were deposited at a powder feed rate of 0.2 g/min. Optical emission spectroscopy was used to diagnose the particle state in plasma jet. The surface morphology and cross-sectional morphology of coatings was characterized by field emission scanning electron microscope. It is found that the amount of YSZ evaporation is significantly enhanced through using a shroud. The coatings with a hybrid microstructure of splats and nanoclusters were deposited perpendicular to the coatings. The nanostructured clusters deposited out of the vapor are presented at splat interfaces. It is evident that using powders specially designed for PS-PVD and controlling heating of plasma jet to spray particles, PS-PVD deposition for a hybrid microstructure consisting of vapor phase deposit can be realized through conventional plasma spray system. Columnar grain structured YSZ can also be deposited by pure vapor phase at the side surface of the substrate.     

An Experimental Investigation and Analysis of PTAW Process

Experiments are conducted to deposit SS304 L powders on SS316 plates by plasma transfer arc welding process with varying four input process parameters, namely scanning speed, powder feed rate, stand-off distance, and current. The effects of these four input process parameters on deposition geometry, dilution, and bead continuity are investigated in this study. Attempts have been made to explain the experimental results with only two compound parameters, “energy deposition per length” and “powder deposition per length” instead of four independent input process parameters. It is observed that the variation of dilution is very little when the scanning speed increases from 100 to 600 mm/min and other process parameters remain constant. When the powder feed rate increases and other parameters remain constant, initially the dilution decreases rapidly and attains a minimum value which do not change further with increase in powder feed rate. It is also observed that the dilution remains almost constant around 6–9% as the stand-off distance changes from 7 to 11 mm and other process parameters remain constant. The formation of nonuniform bead is found to be due to insufficient energy deposition per length per mass of supplied powder.     

Simultaneous Deposition of Powder in Three Parallel-Oriented Cylindrical Dies

The inhomogeneity of bulk density distribution created during the die filling process might cause quality problems for powder compacts, such as distortion, lamination, and cracking. To avoid these problems, understanding the die filling process and ensuring a uniform pre-compaction powder deposition are necessary. The second-generation pressure deposition tester (PDT-II) was developed to investigate simultaneous deposition of powder into multiple dies. Its design requirements and new features were proposed through evaluating the main strength and limitations of the mass deposition tester (MDT). The operation of the PDT-II and analysis of its data showed that it generates real-time deposition profiles of the entire process for multiple locations. PDT-II data can be used to study the effects of various filling-related parameters (such as die shape, powder flowability, and feed shoe speed) on the deposition process and final pressure distribution. For cylindrical dies filled with a granulated powder with d₅₀ = 600 μm (1) at low feed shoe speeds (20 and 100 mm/s), the half circle close to the leeward end had higher final pressure values than the forward half circle; (2) at high feed shoe speed (500 mm/s), the final pressure distribution was more uniform than at lower feed shoe speed; (3) the final within-die pressure distribution at the bottom of the dies was not always symmetrical about the center line of the feed shoe movement direction, even though sometimes it was quite symmetrical; (4) the overall trend was that pressure decreases with increasing radial distance for lower feed shoe speeds; and (5) higher feed shoe speed (500 mm/s) resulted in higher final pressure values (774.5 to 1424.5 Pa) than lower feed shoe speeds (20 and 100 mm/s) (235.2 to 1136.0 Pa) at most of the locations. The results proved that feed shoe speed does have an effect on pressure distribution and its uniformity.     

Electrophoretic deposition of polyetheretherketone (PEEK) and PEEK/Bioglass® coatings on NiTi shape memory alloy wires

Polyetheretherketone (PEEK) and PEEK/Bioglass® coatings were produced on shape memory alloy (NiTi, Nitinol®) wires using electrophoretic deposition (EPD). Best results were achieved with suspensions of PEEK powders in ethanol in the range (1–6 wt%), using a deposition time of 5 minutes and applied voltage of 20 Volts. EPD using these parameters led to high quality PEEK coatings with a homogeneous microstructure along the wire length and a uniform thickness of up to 15 μm without development of cracks or the presence of large voids. Suspensions of PEEK powders in ethanol with addition of Bioglass® particles (0.5–2 wt%) (size < 5 μm) were used to produce PEEK/Bioglass® coatings. Sintering was carried out as a post EPD process in order to densify the coatings and to improve the adhesion of the coatings to the substrate. The sintering temperature was 340 °C, sintering time 20 min and heating rate 300 °C/h. Sintering led to uniform and dense PEEK and PEEK/Bioglass® coatings without any cracks. The bioactive behaviour of PEEK/Bioglass® composite coatings was investigated by immersion in acellular simulated body fluid (SBF) for up to two weeks. As expected, hydroxyapatite crystals formed on the surface of the coated wires after 1 week in SBF, confirming the bioactive character of the coatings. The results have demonstrated for the first time that EPD is a very convenient method to obtain homogeneous and uniform bioactive PEEK and PEEK/Bioglass® coatings on Nitinol® wires for biomedical applications.     

Properties of fluorinated silica glass deposited at low temperature by atmospheric plasma-enhanced chemical vapor deposition

The atmospheric pressure plasma-enhanced chemical vapor deposition of fluorinated silica glass was demonstrated at a temperature of 120 °C. The process was carried out by simultaneously feeding tetramethylcyclotetrasiloxane (TMCTS) and triethoxyfluorosilane (TEOFS) into the afterglow of helium and oxygen plasma. The effect of the flow rate of the fluorinated precursor on the growth rate, composition, and optical properties was examined. The ratio of atomic fluorine to atomic silicon increased up to 10% at a TEOFS/TMCTS atomic Si feed ratio of 1.3 and then leveled off. Coatings made from pure TMCTS and both precursors showed higher surface roughness and porosity, and more hydroxyl content compared to coatings made from pure TEOFS. The refractive indices at 633 nm of films produced using pure TMCTS, a TEOFS/TMCTS atomic Si feed ratio of 1.3 and pure TEOFS were 1.457, 1.449, and 1.411, respectively.     

Uniformity of Powder Die Filling Using a Feed Shoe: A Review

The process of die filling for achieving a uniform fill is a critical unit operation that is far from being sufficiently understood. Factors influencing powder flow from a feed shoe and powder deposition into a die are reviewed in this article. The factors include feed shoe speed, feed shoe holding time over the die, particle shape and size, powder size distribution, die shape and size, die configuration, filling intensity, filling direction, and the height of powder in the feed shoe. Devices suitable for evaluating the quality of powder deposition in dies need to be more: (1) specific to simulate the filling process, (2) versatile to encompass different filling parameters, and (3) able to provide quantitative evaluation. Recommendations to improve die deposition and density uniformity are given with respect to powder characteristics and die and feed shoe properties. New devices using load cells, pressure sensors, or tactile sensors to investigate powder deposition are important for further the investigation of the deposition process and spatial density uniformity. These primary measurement devices have the potential to bridge the knowledge gap and enable the development of discrete and/or continuum-concept computational models for the dynamic die-fill process.     

Uniformity of Powder Die Filling Using a Feed Shoe: A Review

The process of die filling for achieving a uniform fill is a critical unit operation that is far from being sufficiently understood. Factors influencing powder flow from a feed shoe and powder deposition into a die are reviewed in this article. The factors include feed shoe speed, feed shoe holding time over the die, particle shape and size, powder size distribution, die shape and size, die configuration, filling intensity, filling direction, and the height of powder in the feed shoe. Devices suitable for evaluating the quality of powder deposition in dies need to be more: (1) specific to simulate the filling process, (2) versatile to encompass different filling parameters, and (3) able to provide quantitative evaluation. Recommendations to improve die deposition and density uniformity are given with respect to powder characteristics and die and feed shoe properties. New devices using load cells, pressure sensors, or tactile sensors to investigate powder deposition are important for further the investigation of the deposition process and spatial density uniformity. These primary measurement devices have the potential to bridge the knowledge gap and enable the development of discrete and/or continuum-concept computational models for the dynamic die-fill process.     

纯铝粉末等径角挤压固结模拟及实验研究

目的研究纯铝粉末在等径角挤压(ECAP)工艺下的固结行为。方法采用Deform软件对铝粉的ECAP工艺进行热力耦合有限元模拟分析,研究粉末致密情况、静水压力情况以及温度场分布情况等,剖析铝粉的固结行为。通过铝粉的ECAP实验对粉末的固结质量进行综合评定。结果有限元模拟表明,ECAP剪切转角处静水压力最大,温度最高,相对密度接近0.97,接近完全致密材料,为粉末固结提供了必要前提。实验结果表明,在200℃条件下,可以通过ECAP工艺将铝粉固结成为块体材料。结论 ECAP变形过程能够在较低的温度条件下实现粉末的固结行为。     

An Evaluation of Quality of Joints of Two Dissimilar Metals by Diffusion Bonding using Ultrasonic C Scan

Diffusion bonding of commercially available pure aluminum/copper was carried out between the temperatures of 400°C and 500°C for 60 min under the pressure of 5–15 MPa in vacuum. The effects of temperature and pressure on the microstructure of aluminum/copper diffusion bonded joints were analyzed. The interface micrographs of the bonded samples were observed in optical and scanning electron microscope (SEM) images. The soundness of the bond was evaluated by destructive and nondestructive (ultrasonic C scan) testing methods. The quality of the bonded joints was evaluated by the intensity of the echo and its images of ultrasonic testing and was correlated with destructive parameters such as the strength ratio. Chemical compositions of the interface and the fractured surface of the bonded samples were characterized by energy dispersive spectroscopy (EDS). EDS patterns were confirmed by the formation of the different compositions at the interface of the bonded samples. Better bonding characteristics were observed by diffusion bonding optimum parameters at 450°C with an applied pressure of 15 MPa for 60 min.     

Effect of Ethylene Flow Rate and CVD Process Time on Diameter Distribution of MWCNTs

To date, focus of the research activities in nanoscience was to control the chemical vapor deposition (CVD) growth of carbon nanotubes (CNTs) by changing the precursor pressure and process temperature. The effect of the precursor flow rate and process time on CNTs growth parameters has been overlooked in past studies and therefore is very little known. This study was focused on the optimization of the ethylene flow rate and CVD process time for CNTs growth over Fe₂O₃/Al₂O₃ catalyst in a fluidized bed chemical vapor deposition (FBCVD) reactor, operating at atmospheric pressure. Argon and hydrogen were considered as the carrier and supporting gases, respectively. Transmission electron microscope (TEM) and Scanning Electron Microscopy (SEM) were used to investigate the surface morphology, nanostructures, purity and yield of the grown CNTs. In-depth analysis revealed an increase in tube length, yield and the carbon concentration with ethylene flow rate in the range of 50–110 sccm. However, an inverse relationship between flow rate and tube diameter distribution was predicted in the given work. The most favorable results were obtained at an ethylene flow rate of 100 sccm and a CVD process time of 60 minutes. The dense and homogeneous growth of relatively pure nanotubes of increased tube length and narrow diameter distribution, in the range of 20–25 nm, was observed at optimized flow rate and process time.     

Deposition efficiency of low pressure cold sprayed aluminum coating

Low pressure cold spraying (LPCS) is different from high pressure cold spraying because it is capable of onsite operation with compaction system and flexible spray gun. However, the deposition efficiency is much low for efficient onsite reparation, it is important to know more about the influence of spraying parameters on deposition efficiency of LPCS. To verify the relationship between the spray parameters (temperature, standoff distance, powder feeding rate, and transverse speed) and the deposition efficiency, a DYMET413 commercial LPCS system was used to prepare coating under different parameters. The deposition efficiency increases linearly as the gas temperature increases. The optimal alumina content in powders is about 30%, the optimal distance is 25?mm for the powder used in this study. The deposition efficiency of powder increases as the transverse speed of nozzle decreases. It is hard to predict the deposition efficiency by numerical methods since the deposition behavior in a composite powder system is influenced by a number of factors. The interaction between particles, the erosion effect of alumina and under critical velocity particles all can influence the deposition behavior.     

Effect of SiC Nanoparticles Content and Mg Addition on the Characteristics of Al/SiC Composite Powders Produced via In Situ Powder Metallurgy Method

In the present study, the effect of the nanosized SiC particles loading and Mg addition on the characteristics of Al/SiC composite powders produced via a relatively new method called “in situ powder metallurgy” (IPM) was investigated. Specified amounts of SiC particles (within a size range of 250 to 600 µm) together with SiC nanoparticles (average size of 60 nm) were preheated and added to aluminum melt. This mixture was stirred via an impeller at a certain temperature for a predetermined time. The liquid droplets created by this process were then subsequently cooled in air and screened through 250 µm sieve to separate micron-sized SiC particles from solidified aluminium powder particles containing nanosized SiC particles. Results of SEM and TEM studies together with microhardness measurements revealed that the commercially pure (CP) Al could not embed as-received SiC particles. However, the nanosized particles were distributed uniformly in the Al-1 wt% Mg powders. The process yield and microhardness of the Al-1Mg composite powders increased with increasing the contributed amount of nanosized SiC particles.     

Powder Deposition in Three Parallel-Oriented Dies of Different Shapes

Uniformity of bulk density distribution during the die filling process is required to minimize quality problems, such as distortion and cracking, for powder compacts. Understanding the die filling process is necessary in ensuring a uniform powder deposition. The second-generation pressure deposition tester (PDT-II) was used to investigate the deposition process and final pressure distribution of powder filling in toroidal, cylindrical, and E-shaped dies. All tests were conducted using a spray-dried free-flowing granular powder. The results indicated that for toroidal dies: (1) the area around 0° orientation (the leeward end) had the highest pressure values (1186.7 to 2498.0 Pa), with the average pressure values of the remaining area 353.7-648.0 Pa; (2) the pressure distribution was symmetrical about the centerline parallel to the feed shoe movement direction; (3) the highest feed shoe speed (500 mm/s) led to the most nonuniform pressure distribution among the three speeds; (4) higher feed shoe speed did not always result in higher final pressure values; and (5) the right die tended to have higher final pressure values (215.0 to 2498.0 Pa) than the center die (95.4 to 2052.5 Pa). For E-shaped dies: (1) the final pressure values of the middle leg (308.9 to 760.7 Pa) were higher than those of the left and the right legs (148.9 to 530.3 Pa); (2) the area along the backside had the highest final pressure value (1054.6 to 1303.8 Pa); (3) the pressure distribution was symmetrical about the centerline parallel to the feed shoe movement direction; and (4) neither the center die nor the right die always had higher pressure values than the other one at all locations. Comparison between cylindrical and toroidal dies indicated that: (1) neither of the two die shapes (cylinder and toroid) led to consistently higher or lower final pressure values at all locations and (2) for all three feed shoe speeds, the toroidal die had higher average final pressure values in the 0° orientation.     

Development,characterization and erosion wear response of plasma sprayed fly ash–aluminum coatings

This paper describes the processing, characterization and the erosion wear response of a new class of metal–ceramic composite coatings deposited on metal substrates by plasma spraying. Coatings are developed on aluminum substrates using fly ash pre-mixed with aluminum powder in different weight proportions at various plasma torch power levels ranging from 9 to 18 kW DC. The coatings are characterized in terms of thickness, interface adhesion strength and deposition efficiency. Maximum adhesion strength of about 35 MPa is recorded with coatings deposited at 12 kW power level. It is noticed that the adhesion strength of fly ash coating is improved with pre-mixing of aluminum up to 15 wt.% in the feed material. To study the erosion wear behavior of the coatings, a plan of experiments based on the Taguchi technique is used to acquire the erosion test data in a controlled way. An orthogonal array and signal-to-noise ratio are employed to investigate the influence of the impingement angle, impact velocity, erodent size, stand-off-distance and the aluminum content in the feed stock on the erosion rate. The study reveals that the impact velocity is the most significant factor influencing the erosion wear rate of these coatings.     

Modeling of Simultaneous Deposition of Powder in Three Parallel-Oriented Cylindrical Dies

Die filling is a critical unit operation that is far from being sufficiently understood. No models or methods published can be used to study or simulate the feed shoe filling process or pressure (mass) increase for real-world problems involving a large number of 3-D particles of various shapes and sizes. In order to further understanding of the die-filling process, models were developed and verified to simulate the pressure ratio increase for the entire filling process by using the second-generation pressure deposition tester (PDT-II). The results indicated that the entire pressure increase profile could be divided into 10 stages, and all the stages could be simulated by a rate equation, based on the data collected and the physics of the filling process. Based on the powder deposition characteristics, the overall rate equation for all 10 stages is: dP _p /dτ = αP _p F(τ) + β, where P _p is prorated pressure at normalized time τ, and F(τ), α, and β are location-specific forcing function and constants. Furthermore, for stage 1 with the largest amount of powder deposited, the rate equation is dP _p /dτ = αP _p /(e ^bτ ? 1). The average, maximum, and minimum values of the root-mean-square error (RMSE) for a total of 17 locations in the vicinity of the center (r ≤ 4 mm) of the center die are 0.13, 0.19, and 0.11, respectively. The average, maximum, and minimum values of the average relative difference (ARD) for a total of 17 locations in the vicinity of the center (r ≤ 4 mm) of the center die are 0.07, 0.09, and 0.06, respectively.     

Thermal analysis of friction stir processing (FSP) using arbitrary Lagrangian-Eulerian (ALE) and smoothed particle hydrodynamics (SPH) meshing techniques

Friction stir processing (FSP), a derivation of friction stir welding (FSW) is a material processing method which is used to locally modify the microstructure and texture of a given material. In friction stir processing (FSP), the heat produced by the frictional force and material deformation plays a significant role in producing a good surface quality. Therefore, the thermal modeling of friction stir processing (FSP) requires accurate boundary conditions and an appropriate mesh modelling technique. In this study, the thermal behavior of friction stir processing (FSP) using the aluminum alloy 6061-T6 for different process parameters is investigated. To solve complicated governing equations, two finite element formulations have been utilized; i. e. an arbitrary Lagrangian-Eulerian (ALE) and a smoothed particle hydrodynamics (SPH). For the arbitrary Lagrangian-Eulerian (ALE), a three-dimensional (3D) fully coupled thermomechanical finite element model using a modified Coulomb friction and Johnson-Cook material law has been used. The results show that, the temperature behavior is asymmetrical in the cross section and the peak temperature is approximately around 60 %–80 % of the melting temperature of the AA6061-T6. Moreover, it is seen that as the rotating velocity increases, the peak temperature is also increased; and the peak temperature decreases as the transverse speed increases. Finally, a good correlation between the calculated values and the literature is found.     

Spark plasma sintering and thermoelectric evaluation of nanocrystalline magnesium silicide (Mg2Si)

Recently magnesium silicide (Mg₂Si) has received great interest from thermoelectric (TE) society because of its non-toxicity, environmental friendliness, comparatively high abundance, and low production material cost as compared to other TE systems. It also exhibited promising transport properties, including high electrical conductivity and low thermal conductivity, which improved the overall TE performance (ZT). In this work, Mg₂Si powder was obtained through high energy ball milling under inert atmosphere, starting from commercial magnesium silicide pieces (99.99 %, Alfa Aesar). To maintain fine microstructure of the powder, spark plasma sintering (SPS) process has been used for consolidation. The Mg₂Si powder was filled in a graphite die to perform SPS and the influence of process parameters as temperature, heating rate, holding time and applied pressure on the microstructure, and densification of compacts were studied in detail. The aim of this study is to optimize SPS consolidation parameters for Mg₂Si powder to achieve high density of compacts while maintaining the nanostructure. X-Ray diffraction (XRD) was utilized to investigate the crystalline phase of compacted samples and scanning and transmission electron microscopy (SEM & TEM) coupled with Energy-Dispersive X-ray Analysis (EDX) was used to evaluate the detailed microstructural and chemical composition, respectively. All sintered samples showed compaction density up to 98 %. Temperature dependent TE characteristics of SPS compacted Mg₂Si as thermal conductivity, electrical resistivity, and Seebeck coefficient were measured over the temperature range of RT 600 °C for samples processed at 750 °C, reaching a final ZT of 0.14 at 600 °C.