No description available.

Black liquor is an intermediate product of pulp production. Recovery boilers process black liquor to recover the inorganic material for recycling in the mill and to generate electricity and steam for the paper mill. Black liquor droplet combustion rates and mechanisms dictate many aspects of recovery boiler performance. This investigation documents new experimental data on single droplet pyrolysis and combustion in a laboratory furnace that mimics many of the essential features of commercial boilers (temperature, composition, droplet size, etc.). These experiments monitored single droplets placed on a thermocouple wire and suspended from a mass balance. Simultaneous video images and pyrometry data provide mass loss and internal temperature data. These investigations provide an extensive data set from which to validate a model and insight into the mechanisms of combustion. Particles burning in air expelled ejecta from the particle during the entire combustion process, though ejection rates during the late stages of char combustion were observed to be higher than during other stages. In addition, char burning began almost the instant the particle entered the reactor; showing significant overlap in the combustion processes. A transient, 1-dimensional, single-droplet model describes droplet combustion. This model solves the momentum, energy, species continuity, and overall continuity equations using the control volume method. The model uses the power-law scheme for combined advection diffusion, and the fully-implicit scheme for the time step. It predicts internal velocities, gas and solid temperatures (assumed equal), pressure, and composition. Pressure and velocity equations use Darcy's Law for flow through a porous medium. Modeling results show the large effect of swelling on all particle properties. This model describes the flame region by extending the control volume into the gas phase.

Investigou-se a influência da inclinação das paredes de dentina (paralela ou perpendicular à ação da gravidade) e da variação regional dos espécimes (terços cervical ou oclusal) na resistência adesiva e na espessura da camada de adesivo. Vinte e cinco molares humanos foram seccionados no sentido mésio-distal e paralelamente ao seu longo eixo, obtendo-se secções vestibulares e linguais, as quais foram lixadas produzindo-se superfícies planas de dentina. Sistemas adesivos (Adper Single Bond-SB e Prime & Bond 2.1- PB2.1) foram aplicados na dentina, ora paralelamente ora perpendicularmente à ação da gravidade, padronizando-se o volume de adesivo (3,5 µl por gota) através do uso de uma micropipeta e seguindo-se as instruções dos fabricantes. Os grupos de estudo foram: 1A (SB, paralelo), 1B (SB, perpendicular), 2A (PB2.1, paralelo) e 2B (PB2.1, perpendicular). Após 24h de armazenamento em água deionizada a 37°C, espécimes foram preparados na forma de palitos de dentina com área adesiva de 0,8 mm2, aproximadamente. Na seqüência, foi determinada a espessura do adesivo de cada espécime, em micrômetros (µm), sob microscopia óptica (200X de aumento) e auxílio do programa Image Pro-Plus 4.5. Posteriormente, os espécimes foram submetidos à microtração sob velocidade de 0,5 mm/min. Todos os espécimes fraturados foram examinados sob microscopia óptica (40X de aumento) para a determinação dos planos de fratura. Os dados coletados foram submetidos aos testes ANOVA a 1 e 2 critérios e SNK (? = 0,05). Para determinação da correlação entre resistência adesiva e espessura do adesivo foi utilizado o teste de Correlação de Pearson. Os valores médios (MPa±d.p.) de resistência adesiva dos grupos 2A (52,93±15,19) e 2B (52,27±16,54) foram superiores àqueles dos grupos 1A (39,09±12,90) e 1B (32,94±12,42), independente da inclinação das paredes de dentina dos mesmos. Não houve diferença nos valores de resistência adesiva à dentina, independente da variação regional do espécime. Os valores médios (µm±d.p.) de espessura da camada de adesivo dos grupos 1A (11,24±2,92) e 1B (18,11±7,31) foram superiores àqueles dos grupos 2A (4,20±1,81) e 2B (3,87±1,29) (p > 0,05). O grupo 1B promoveu os maiores valores de espessura de adesivo, seguido do grupo 1A. As espessuras do adesivo nos grupos 2A e 2B apresentaram-se similares entre si. Houve influência da variação regional do espécime na espessura de adesivo somente para o grupo 1B. Não houve correlação entre resistência adesiva e espessura de adesivos para ambos SB e PB2.1 (r = -0,224, p = 0,112 e r = 0,099, p = 0,491, respectivamente). Conclui-se que a influência da inclinação das paredes de dentina e da variação regional dos espécimes na espessura da camada de adesivo é material-dependente, porém não influem na resistência adesiva dos sistemas adesivos à dentina. / To determine the effect of the inclination of dentin surfaces (parallel or perpendicular to the force of gravity) and the regional variation of specimens (cervical or occlusal thirds) on the dentin bond strength and adhesive layer thickness. Twenty-five extracted human molars were sectioned in a mesio-distal direction to expose flat dentin. Standardized drop volumes of adhesive systems (Single Bond-SB and Prime & Bond 2.1-PB2.1) were applied to dentin according to manufacturers instructions. Teeth were randomly divided into the following groups: 1A (SB, parallel), 1B (SB, perpendicular), 2A (PB2.1, parallel) and 2B (PB2.1, perpendicular). Teeth were stored in 37°C distilled water for 24h and then serially sectioned to obtain sticks with cross-sectional area of approximately 0.8 mm2 for microtensile bond strength test (MTBS). The thickness of adhesive layer of the MTBS specimen was determined in a light microscope at 200X magnification. Forty-eight hours after adhesion procedures the specimens were subjected to MTBS at a crosshead speed of 0.5 mm/min. After testing, the fracture modes of each specimen were determined by examination under a 40X magnification. One and two-way ANOVA and Student- Newman-Keuls-SNK tests were performed do determine differences in MTBS and in adhesive layer thickness among groups. The correlation between MTBS and adhesive layer thickness was compared with Pearson Product Moment Correlation ('alfa' = 0.05). Mean values (MPa±s.d.) for bond strength were higher for groups 2A (52.93±15.19) and 2B (52.27±16.54) than for groups 1A (39.09±12.90) and 1B (32.94±12.42), regardless of the position of dentin surfaces. There was no difference in MTBS, despite the regional variation of specimens. The thickness of adhesive systems (µm±s.d.) was higher for groups 1A (11.24±2.92) and 1B (18.11±7.31) than those for groups 2A (4.20±1.81) and 2B (3.87±1.29). Group 1B provided the greater mean values of adhesive thickness followed by the Group 1A. Similar adhesive thicknesses were found for Groups 2A and 2B, but significantly lower than the other groups. There was a significant influence of the regional variation of specimens on the adhesive thickness of group 1B. No correlation was found between bond strength and adhesive layer thickness for both SB and PB 2.1 (r = -0.224, p = 0.112 and r = 0.099, p = 0.491, respectively). The inclination of dentin surface and the regional variation of specimens on the adhesive layer thickness are materialdependent. These variables do not influence the adhesive systems bond strength to dentin.

Increasing global energy demands and diminishing supplies of conventional fuels are forcing the world to focus more on alternative power sources that are both renewable and ecologically benign. Solar energy is clean, regularly available and can be harvested without sacrificing valuable land space. Due to the associated cost of solar cells, however a very small portion of the world’s energy needs are supplied by the sun. Solution-processable organic photovoltaics (OPVs) offer the promise of lower production costs relative to conventional (silicon) solar cell technology. Solution-processing can be performed using reel-to-reel manufacturing, with printing and coating techniques that are significantly cheaper than current processing methods for inorganic semiconductors. Although OPV efficiency values currently remain inferior to those of conventional solar cells, the rate of improvement is much higher in OPVs than in other solar cell technologies. Recently an efficiency exceeding 10% was reported for organic solar cells. An important difference between organic and conventional solar cells is the charge carrier mobility of the semiconductors, which tends to be relatively low in organic semiconductors. Recent advances in molecular design have led to polymer semiconductor materials that possess hole mobility values similar to that of amorphous silicon. The present study investigates potential improvements in OPV devices that can be achieved through the application of high hole mobility polymer semiconductor donors. Two diketopyrrolopyrrole-based polymers, PDQT and PDBFBT, were selected for the role of electron donor in OPV devices due to their high mobilities and their optimum optical and electrical properties. Optimization of the process parameters was performed using PC61BM as the acceptor. A relatively high quantity of PC61BM (3 - 4 × the weight of the donor) is required in the donor-acceptor blends of both polymers in order to balance the high hole mobility. For these donor-acceptor blends, a solvent system consisting of chloroform/ortho-dichlorobenzene (4:1 v/v) is necessary for proper solubility, and an additive, 1,8-diiodooctane, is required to achieve an acceptable morphology. The main benefit expected from the use of high mobility semiconductors is reduced charge recombination. This was studied in relation to the active layer thickness in standard and inverted OPV devices prepared using PC61BM as the acceptor. Normally the thickness of the active layer is required to be low (~100 nm) due to the poor charge transport mobility of the carriers. In this study, rather consistent power conversion efficiencies were achieved throughout a wide range of active layer thicknesses (~100 nm to ~800 nm). A comparison between standard and inverted device configurations demonstrates that the inverted configuration is more suitable for achieving thicker active layers when a high hole mobility donor is used. This is attributed to the longer hole collection path in the inverted structure, which can benefit from using a high hole mobility material. Increasing the absorption spectra of the donor-acceptor blend was studied by substituting PC71BM for PC61BM. The improved absorption leads to greater charge generation. In PDQT devices, the increase in absorption that is contributed by PC71BM appears to be of greatest benefit when active layers are not very thick. Therefore, when thick active layers (>500 nm) are required, the use of PC61BM is sufficient, in conjunction with a high mobility donor. Finally, an increase in a polymer’s crystallinity can often lead to greater mobility. This can be accomplished through various annealing techniques. The improved crystallinity of PDBFBT that occurs as a result of thermal annealing was studied in OPV applications. Although hole mobility of PDBFBT in the lateral direction improves with thermal annealing, mobility in the vertical direction decreases with increasing temperature. This suggests that the crystallinity of PDBFBT is oriented in the lateral direction as opposed to the vertical direction, thereby directing charge flow horizontal to the surface. With thermal annealing, an optimal amount of PC61BM added to PDBFBT can increase the vertical mobility to fairly high values. Nevertheless, the efficiency of standard and inverted OPV devices decreases with increased annealing temperature. This is attributed to agglomeration of PC61BM that occurs from an increase in annealing temperature. The results of this study demonstrate that thermal annealing is not beneficial for PDBFBT:PC61BM films in OPV applications due to the vertical orientation of devices. All of the studies presented in this work involve the use of high hole mobility polymer semiconductors as donor materials for OPV applications. This work will provide a deeper understanding of the properties required for the development of new semiconductor materials in OPV applications. Furthermore, this work will be very useful for the design of device structures for more feasible manufacturing of large area OPV devices via high speed roll-to-roll printing processes.

A heterocyclic aromatic rigid-rod polymer poly-p-phenylene-benzobisoxazole (PBO) was applied as the opto-electronic layer¡Fand a conducting material of poly(3,4-ethylenedioxythio-phene):poly(4-styrenesulfonic acid) (PEDOT: PSS) was used as the hole transport layer. Aluminum (Al) and indium tin oxide (ITO) were served as device cathode and anode¡Arespectively, fabricated into a bi-layer structure of ITO/PEDOT:PSS/PBO/Al for electrical and luminescence responses. This research demonstrated an increase of current density and a decrease of threshold voltage with a decrease of PBO layer thickness from 90 nm to 27 nm to facilitate electron tunneling and electron-hole recombination. With a lower spin coating speed, polymer chain would aggregate and inter-penetrate resulted in red-shift of electroluminescence (EL) emission spectrum. Furthermore, micro-cavity effect might influence EL spectrum by varying layer thickness. Modulation of PBO layer thickness led to tunable EL emission color. It was also demonstrated that an increase of current density and a slightly decrease of threshold voltage with a PEDOT:PSS film thickness changing from 96 nm to 17 nm at a constant PBO layer thickness of 90 nm. Micro-cavity effect thus influenced EL emission for a tunable emission color. Photolithography was applied to obtain ITO substrate of grating depth of periodic variation and then coated with a PEDOT:PSS leading to a grated PEDOT:PSS layer of periodic thickness. This led to ITO/PEDOT:PSS/PBO/Al device showing broadened EL emission spectra.

Increasing global energy demands and diminishing supplies of conventional fuels are forcing the world to focus more on alternative power sources that are both renewable and ecologically benign. Solar energy is clean, regularly available and can be harvested without sacrificing valuable land space. Due to the associated cost of solar cells, however a very small portion of the world’s energy needs are supplied by the sun. Solution-processable organic photovoltaics (OPVs) offer the promise of lower production costs relative to conventional (silicon) solar cell technology. Solution-processing can be performed using reel-to-reel manufacturing, with printing and coating techniques that are significantly cheaper than current processing methods for inorganic semiconductors. Although OPV efficiency values currently remain inferior to those of conventional solar cells, the rate of improvement is much higher in OPVs than in other solar cell technologies. Recently an efficiency exceeding 10% was reported for organic solar cells. An important difference between organic and conventional solar cells is the charge carrier mobility of the semiconductors, which tends to be relatively low in organic semiconductors. Recent advances in molecular design have led to polymer semiconductor materials that possess hole mobility values similar to that of amorphous silicon. The present study investigates potential improvements in OPV devices that can be achieved through the application of high hole mobility polymer semiconductor donors. Two diketopyrrolopyrrole-based polymers, PDQT and PDBFBT, were selected for the role of electron donor in OPV devices due to their high mobilities and their optimum optical and electrical properties. Optimization of the process parameters was performed using PC61BM as the acceptor. A relatively high quantity of PC61BM (3 - 4 × the weight of the donor) is required in the donor-acceptor blends of both polymers in order to balance the high hole mobility. For these donor-acceptor blends, a solvent system consisting of chloroform/ortho-dichlorobenzene (4:1 v/v) is necessary for proper solubility, and an additive, 1,8-diiodooctane, is required to achieve an acceptable morphology. The main benefit expected from the use of high mobility semiconductors is reduced charge recombination. This was studied in relation to the active layer thickness in standard and inverted OPV devices prepared using PC61BM as the acceptor. Normally the thickness of the active layer is required to be low (~100 nm) due to the poor charge transport mobility of the carriers. In this study, rather consistent power conversion efficiencies were achieved throughout a wide range of active layer thicknesses (~100 nm to ~800 nm). A comparison between standard and inverted device configurations demonstrates that the inverted configuration is more suitable for achieving thicker active layers when a high hole mobility donor is used. This is attributed to the longer hole collection path in the inverted structure, which can benefit from using a high hole mobility material. Increasing the absorption spectra of the donor-acceptor blend was studied by substituting PC71BM for PC61BM. The improved absorption leads to greater charge generation. In PDQT devices, the increase in absorption that is contributed by PC71BM appears to be of greatest benefit when active layers are not very thick. Therefore, when thick active layers (>500 nm) are required, the use of PC61BM is sufficient, in conjunction with a high mobility donor. Finally, an increase in a polymer’s crystallinity can often lead to greater mobility. This can be accomplished through various annealing techniques. The improved crystallinity of PDBFBT that occurs as a result of thermal annealing was studied in OPV applications. Although hole mobility of PDBFBT in the lateral direction improves with thermal annealing, mobility in the vertical direction decreases with increasing temperature. This suggests that the crystallinity of PDBFBT is oriented in the lateral direction as opposed to the vertical direction, thereby directing charge flow horizontal to the surface. With thermal annealing, an optimal amount of PC61BM added to PDBFBT can increase the vertical mobility to fairly high values. Nevertheless, the efficiency of standard and inverted OPV devices decreases with increased annealing temperature. This is attributed to agglomeration of PC61BM that occurs from an increase in annealing temperature. The results of this study demonstrate that thermal annealing is not beneficial for PDBFBT:PC61BM films in OPV applications due to the vertical orientation of devices. All of the studies presented in this work involve the use of high hole mobility polymer semiconductors as donor materials for OPV applications. This work will provide a deeper understanding of the properties required for the development of new semiconductor materials in OPV applications. Furthermore, this work will be very useful for the design of device structures for more feasible manufacturing of large area OPV devices via high speed roll-to-roll printing processes.

Investigou-se a influência da inclinação das paredes de dentina (paralela ou perpendicular à ação da gravidade) e da variação regional dos espécimes (terços cervical ou oclusal) na resistência adesiva e na espessura da camada de adesivo. Vinte e cinco molares humanos foram seccionados no sentido mésio-distal e paralelamente ao seu longo eixo, obtendo-se secções vestibulares e linguais, as quais foram lixadas produzindo-se superfícies planas de dentina. Sistemas adesivos (Adper Single Bond-SB e Prime & Bond 2.1- PB2.1) foram aplicados na dentina, ora paralelamente ora perpendicularmente à ação da gravidade, padronizando-se o volume de adesivo (3,5 µl por gota) através do uso de uma micropipeta e seguindo-se as instruções dos fabricantes. Os grupos de estudo foram: 1A (SB, paralelo), 1B (SB, perpendicular), 2A (PB2.1, paralelo) e 2B (PB2.1, perpendicular). Após 24h de armazenamento em água deionizada a 37°C, espécimes foram preparados na forma de palitos de dentina com área adesiva de 0,8 mm2, aproximadamente. Na seqüência, foi determinada a espessura do adesivo de cada espécime, em micrômetros (µm), sob microscopia óptica (200X de aumento) e auxílio do programa Image Pro-Plus 4.5. Posteriormente, os espécimes foram submetidos à microtração sob velocidade de 0,5 mm/min. Todos os espécimes fraturados foram examinados sob microscopia óptica (40X de aumento) para a determinação dos planos de fratura. Os dados coletados foram submetidos aos testes ANOVA a 1 e 2 critérios e SNK (? = 0,05). Para determinação da correlação entre resistência adesiva e espessura do adesivo foi utilizado o teste de Correlação de Pearson. Os valores médios (MPa±d.p.) de resistência adesiva dos grupos 2A (52,93±15,19) e 2B (52,27±16,54) foram superiores àqueles dos grupos 1A (39,09±12,90) e 1B (32,94±12,42), independente da inclinação das paredes de dentina dos mesmos. Não houve diferença nos valores de resistência adesiva à dentina, independente da variação regional do espécime. Os valores médios (µm±d.p.) de espessura da camada de adesivo dos grupos 1A (11,24±2,92) e 1B (18,11±7,31) foram superiores àqueles dos grupos 2A (4,20±1,81) e 2B (3,87±1,29) (p > 0,05). O grupo 1B promoveu os maiores valores de espessura de adesivo, seguido do grupo 1A. As espessuras do adesivo nos grupos 2A e 2B apresentaram-se similares entre si. Houve influência da variação regional do espécime na espessura de adesivo somente para o grupo 1B. Não houve correlação entre resistência adesiva e espessura de adesivos para ambos SB e PB2.1 (r = -0,224, p = 0,112 e r = 0,099, p = 0,491, respectivamente). Conclui-se que a influência da inclinação das paredes de dentina e da variação regional dos espécimes na espessura da camada de adesivo é material-dependente, porém não influem na resistência adesiva dos sistemas adesivos à dentina. / To determine the effect of the inclination of dentin surfaces (parallel or perpendicular to the force of gravity) and the regional variation of specimens (cervical or occlusal thirds) on the dentin bond strength and adhesive layer thickness. Twenty-five extracted human molars were sectioned in a mesio-distal direction to expose flat dentin. Standardized drop volumes of adhesive systems (Single Bond-SB and Prime & Bond 2.1-PB2.1) were applied to dentin according to manufacturers instructions. Teeth were randomly divided into the following groups: 1A (SB, parallel), 1B (SB, perpendicular), 2A (PB2.1, parallel) and 2B (PB2.1, perpendicular). Teeth were stored in 37°C distilled water for 24h and then serially sectioned to obtain sticks with cross-sectional area of approximately 0.8 mm2 for microtensile bond strength test (MTBS). The thickness of adhesive layer of the MTBS specimen was determined in a light microscope at 200X magnification. Forty-eight hours after adhesion procedures the specimens were subjected to MTBS at a crosshead speed of 0.5 mm/min. After testing, the fracture modes of each specimen were determined by examination under a 40X magnification. One and two-way ANOVA and Student- Newman-Keuls-SNK tests were performed do determine differences in MTBS and in adhesive layer thickness among groups. The correlation between MTBS and adhesive layer thickness was compared with Pearson Product Moment Correlation ('alfa' = 0.05). Mean values (MPa±s.d.) for bond strength were higher for groups 2A (52.93±15.19) and 2B (52.27±16.54) than for groups 1A (39.09±12.90) and 1B (32.94±12.42), regardless of the position of dentin surfaces. There was no difference in MTBS, despite the regional variation of specimens. The thickness of adhesive systems (µm±s.d.) was higher for groups 1A (11.24±2.92) and 1B (18.11±7.31) than those for groups 2A (4.20±1.81) and 2B (3.87±1.29). Group 1B provided the greater mean values of adhesive thickness followed by the Group 1A. Similar adhesive thicknesses were found for Groups 2A and 2B, but significantly lower than the other groups. There was a significant influence of the regional variation of specimens on the adhesive thickness of group 1B. No correlation was found between bond strength and adhesive layer thickness for both SB and PB 2.1 (r = -0.224, p = 0.112 and r = 0.099, p = 0.491, respectively). The inclination of dentin surface and the regional variation of specimens on the adhesive layer thickness are materialdependent. These variables do not influence the adhesive systems bond strength to dentin.

Additive manufacturing (AM) shows great promise for the manufacturing of next-generation engineering structures by enabling the production of engineered cellular structures, overhangs, and reducing waste. Melt-pool geometry prediction and control is critical for widespread implementation of laser powder bed processes due to speed and accuracy requirements. The process mapping approach used in previous work for different alloys and additive manufacturing processes is applied to the selective laser powder bed process for IN625 and 17-4 stainless steel alloys. The ability to predict the resulting steady state melt-pool geometry in terms of process parameters, specifically power and velocity, is explored in detail numerically and experimentally verified. A finite element model was created that simulates powder at the macro scale. This model correlates well with current experiments in showing that small amounts of powder relative to melt-pool depth have negligible effects on resulting geometry. Results indicate that the effect of powder may be negligible when comparing steady state widths of the no powder and one layer of powder cases. The work in this thesis investigates the effect of powder on the resulting steady-state melt-pool geometries for IN625 and 17-4 alloys. This analysis has been extended to the production of overhanging and cellular structures. The successful analysis will allow for better predictions and possible correction for cellular structure production issues as well as overhanging features.

No description available.

Laser Powder Bed Fusion (L-PBF) is a metal additive manufacturing technique that uses a laser beam as a heat source to melt metal powder selectively. Because of the process small layer thicknesses, laser beam diameter, and powder particle size, L-PBF allows the fabrication of novel geometries and complex internal structures with enhanced properties. However, the main disadvantages of the L-PBF process are high costs and a lengthy production time. As a result, shortening the manufacturing process while maintaining comparable properties is exceptionally beneficial. Inconel 625 (IN625) is a nickel-based superalloy becoming increasingly popular in marine, petroleum, nuclear, and aerospace applications. However, the properties of IN625 parts produced by casting or forging are challenging to control due to their low thermal conductivity, high strength and work hardening rate, and high chemical complexity. Furthermore, IN625 alloy is regarded as a difficult-to-machine material. As a result, it is worthwhile to seek new technologies to manufacture complex-shaped IN625 parts with high dimensional accuracy. IN625 alloy is known for its excellent weldability and high resistance to hot cracking; thus, IN625 alloy appears to be a promising candidate for additive manufacturing. This thesis presents an experimentally focused study on optimizing L-PBF processing parameters in IN625 superalloy to increase process productivity while maintaining high material density and hardness. This study had four stages: preliminary, exploratory, modelling, and optimization. The first stage was devoted to conducting a literature review and determining the initial processing parameters. The second stage concentrated on determining the process window, for which single tracks were printed with two high levels of laser power (300, 400 W), five levels of scan speed (500, 700, 900, 1100, 1300 mm/s), and five levels of powder layer thickness (30, 60, 90, 120, 150 µm). Then, the process window was defined after investigating the top views and cross-sections of the tracks. Stage 3 involved printing 48 cubes (10 × 10 × 10 mm^3) with a laser power of 400 W, scan speeds of (700, 900, 1100, 1300 m/s), layer thicknesses of (60, 90, 120, 150 µm), and overlap percentages of (10, 30, 50%). As a result, the density of cubes was measured, and a statistical multiple regression analysis was used to predict it. Stage 4 involved estimating four sets of ideal processing parameters (based on statistical modelling of relative density) and printing 24 cubes (10 × 10 × 10 mm^3), six samples for each set. Finally, the relative density, hardness, and productivity of the samples were assessed, and a trade-off was determined. Even with the thickest powder layer of 150 µm (highest process productivity), samples with a mean relative density greater than 99% (i.e., 99.31% by Archimedes principle and 99.82% by image analysis) were printed. These findings are consistent with previously published results for L-PBF IN625 samples manufactured with smaller layer thicknesses ranging from 20 to 40 µm while maintaining comparable material hardness. The findings of this study are noteworthy because IN625 parts can be printed with higher powder layer thicknesses (less production time) while retaining similar material properties to those published with typical layer thicknesses ranging from 20 to 40 µm. Reduced production time due to optimized processing parameters can lead to significant energy and cost savings. / Thesis / Master of Applied Science (MASc)