Mixed Grain Research Articles

Formation mechanism of basin-like depression defect in electric upsetting process of Ni80A superalloy

A kind of surface instability, basin-like depression defect companied by mixed grain structure at the bottom of large-scale valve during electric upsetting process, would significantly influence the microstructures and mechanical properties of components. In order to analyze the forming process of the basin-like depression defect, a finite element model for the electric upsetting process of Ni80A superalloy was developed using multi-field and multi-scale coupling analysis method. Subsequently, a series of parameters loading path schemes for force and current were designed by varying the initial value, peak value and value level, and their effects on basin-like depression and mixed grain structure were simulated and uncovered. It is concluded that the changes of heating speed and pressurization speed result in the different flow velocities between the inner and outer layers of billet, thus exerting the basin-like depression. Simulation results also indicate that these defects can be optimized through the parameter coordination between force and current. Finally, the validity and reliability of the finite element model were verified by physical experiments in electric upsetting process.

Uneven microstructure in ZK60 alloy as a core of AZ31/ZK60 composite rods

• ZK60-melt core was composed of equiaxed coarse and fine grains. • Large elongated grains and fine equiaxed grains were observed in ZK60-ingot. • Abnormal grain growth was revealed in ZK60-melt core during aging. • Mechanical properties of composites with ZK60-melt and ZK60-ingot cores were improved by aging. AZ31/ZK60 bimetal rods were fabricated via co-extrusion of hybrid billets with ZK60 core prepared by different styles. Uneven microstructures were revealed in ZK60 core of AZ31/ZK60 composite rods prepared by pouring melt (ZK60-melt) into AZ31 sleeve and casting to be ingots to fit AZ31 sleeve (ZK60-ingot) followed by co-extrusion. Compared with the microstructure composed of equiaxed coarse and fine grains in ZK60-melt after co-extrusion, a mixed grain structure with large elongated grains and fine equiaxed grains was observed in ZK60-ingot core in the composite rod. During aging at 180 °C for 12 h abnormal grain growth (AGG) was revealed in ZK60-melt core, but the uneven structure in ZK60-ingot remained thermally stable. Mechanical properties of AZ31/ZK60 composite rods with both ZK60-melt and ZK60-ingot cores were improved significantly by aging.

In situ observation of atomic-scale processes accomplishing grain rotation at mixed grain boundaries

A detailed monitoring of atomic-scale processes accomplishing grain rotation is important for understanding the deformation mechanisms in nanocrystalline metals. However, direct observations have been rare thus far, such that our knowledge about grain rotation has to rely heavily on hypothetical models and simulations. Here, we present in situ atomic-resolution evidence, indicating that the atomic processes accomplishing grain rotation in nanocrystalline Pt depend on the type of grain boundary (GB) separating the rotating grains. The grains around general (mixed) GBs rotate via the Frank–Bilby dislocation activities together with atomic shuffling and disconnection activities, the former being the generation, climb, glide and reaction of GB dislocations, whereas the latter leading to GB migration accompanying the grain rotation. While for the grains with a tilt GB in between: their rotation is accomplished almost entirely via the Frank–Bilby dislocation activities. We also discover that the GB dislocation climb, glide, and reaction often involve the formation and destruction of Lomer-like dislocations.

Influencing Mechanisms of Prior Cold Deformation on Mixed Grain Boundary Network in the Thermal Deformation of Ni80A Superalloy.

Within the grain boundary engineering (GBE) of alloys, a mixed grain boundary network with random grain boundaries interrupted by twin boundaries, contributes to enhancing the overall grain boundary-related properties. The higher density of twin boundaries is pursued herein. Furthermore, a two-stage deformation method, i.e., prior cold deformation followed by thermal deformation, was proposed for improving the mixed grain boundary network in the thermal deformation of Ni80A superalloy. The influence of prior cold deformation on the mixed grain boundary network was investigated through a series of two-stage deformation experiments. The analysis of the stress–strain curves shows that the critical strain for dynamic recrystallization (DRX) and peak strains decrease significantly under the effect of prior cold deformation. In comparison to the necklace-like microstructures that occur after a single thermal deformation, the microstructures apparent after a two-stage deformation are characterized by finer DRX grains with abundant Σ3n twin boundaries, with a significantly improved density of the Σ3n twin boundaries (BLDΣ3n) by a factor of around nine. With increasing prior cold strain, the grain size, after a two-stage deformation, decreases continuously, while the BLDΣ3n increases firstly and then decreases. The mechanisms for improving the mixed grain boundary network via two-stage deformation were uncovered. The sub-grain boundaries formed in prior cold deformation stimulate the nucleation of DRX grains and twins; meanwhile, the driving force for grain boundary migration is enhanced due to prior stored energy. Then, DRX is activated in advance and occurs more completely, thereby promoting the formation of Σ3n twin boundaries.

Optimization of mixed grain size structure for enhancement of thermoelectric figure of merit in p-type BiSbTe-based alloys

Optimization of mixed grain size structure for enhancement of thermoelectric figure of merit in p-type BiSbTe-based alloys

Effect of Deformation Parameters of an Initial Aged GH4169 Superalloy on Its Microstructural Evolution during a New Two-Stage Annealing.

This study aims to explore the effect of deformation parameters on microstructure evolution during the new two-stage annealing method composed of an aging treatment (AT) and a cooling recrystallization annealing treatment (CRT). Firstly, the hot compressive tests with diverse deformation parameters were finished for an initial aged deformed GH4169 superalloy. Then, the same two-stage annealing method was designed and carried out for the deformed samples. The results show that the deformation parameters mainly affect the grain microstructure during CRT by influencing the content, distribution and morphology of the δ phase after deformation. The reason for this is that there is an equilibrium of the content of the δ phase and Nb atom. When the deformation temperature is high, the complete dissolution behavior of the δ phase nuclei promotes the dispersion distribution of the δ phase with rodlike and needle-like shapes during AT. Thus, the fine and heterogeneous microstructure is obtained after annealing because the recrystallization nucleation is enhanced in those dispersed δ phases during CRT. However, when the retained content of δ phase nuclei is high after deformation, the clusters of intragranular δ phases will form during AT, resulting in the pinning of the motion for dislocation. The elimination of the mixed grain microstructure is slowed down due to the low static recrystallization (SRX) nucleation rate within the deformed grain.

Pengaruh penambahan kacang merah dan ketan hitam terhadap sifat sensori dan gizi minuman berbasis jamur tiram dan wijen hitam[[The effect of the addition of red beans and black glutinous rice on the sensory and nutritional properties of oyster mushroom and black sesame-based drinks

One example of a plant-based product is mixed grain-based milk. Mixing various types of grains such as red beans, black glutinous rice, black sesame, and oyster mushrooms is expected to complement the nutritional content and improve the sensory properties of the final product. This research was aimed to determine the effect of the proportion of red beans and black glutinous rice on the mixture of grains and oyster mushrooms on the sensory quality of mixed grain milk and find the best proportion of red beans and black glutinous rice in the mixture of grains and oyster mushrooms that produce plant-based milk with the best sensory quality. This research was conducted in a Randomized Complete Block Design (RCBD) with a single treatment in the form of a comparison of red beans, and black glutinous rice consisting of 6 formulations with 4 replications. Parameters observed were sensory properties (aroma, taste and aftertaste). The sample with the best sensory properties was further analyzed proximate content and amino acid profile. The results showed that addition of red beans and black glutinous rice to plant-based milk on oyster mushrooms and black sesame affected sensory qualities (taste, aroma, and aftertaste). The best treatment was the proportion of 60:30 with a taste score of 7.49 (tends to be savory sweet), an aroma score of 7.73 (tends to be pleasant), an aftertaste score of 7.11 (tends to be normal); a moisture content of 85.29%; a protein content of 1.72%; fat content 0.88%; carbohydrates 11.77%; ash 0.34%; and 61.88 kcal of calories per 100 mL.

Revealing Charge Transfer Dynamics in Methylammonium Lead Bromide Perovskites via Transient Photoluminescence Characterization.

It is an important but difficult issue to identify charge and energy transfer processes in materials where multiple band gaps coexist. Conventional methods using transient absorption and optoelectrical characterization based on devices could not provide a clear picture of transfer dynamics. According to the bimolecular and monomolecular nature of each process, the carrier dynamics is supposed to solve this issue. In this work, we established a novel, convenient and universal strategy based on the calculation of carrier dynamics to distinguish energy/charge transfer and reveal their transfer dynamics in methylammonium lead bromide (MAPbBr3) films with mixing wide-band gap small grains and narrow-band gap large grains. A highly efficient charge transfer process is confirmed with a high negative nonradiative bimolecular recombination coefficient of −2.12 × 10–7 cm–3 s–1, indicating that free carriers within small grains are efficiently transferred from small grains to large grains. As a result, emission from large grains becomes dominant when increasing the photoexcitation intensity. In addition, current-density-dependent electroluminescence results in emission only from large grains, further verifying the charge transfer process. Moreover, it is interesting to find that when decreasing the size of small grains, the charge transfer process is facilitated, leading to an increased nonradiative bimolecular recombination coefficient from −2.12 × 10–7 to −4.01 × 10–7 cm–3 s–1 in large grains. Our work provides a convenient strategy to identify and quantify energy and charge transfer in metal halide perovskites, which can be used to enrich our understanding of perovskite photophysics.

Recrystallization nucleation under close-set δ phase in a nickel-based superalloy during annealing

• Two new effects of the close-set δ phase on the recrystallization nucleation are found. • A new J N theory of recrystallization nucleation feasible domain is proposed and verified. • The new recrystallization nucleation mechanism under close-set precipitated phase particles is revealed. Annealing is one of the most efficient heat treatment to refine the grain microstructure in metal alloys. Prior to the annealing, an aging treatment can be implemented to precipitate the second phases for more nucleation sites in deformed mixed grains during subsequent recrystallization. However, the underlying mechanism behind the second phases and recrystallization has not yet been fully understood. Taking a typical deformed nickel (Ni)-based (GH4169) superalloy as an exapmle, this research aims to clairfy the connections between the recrystallization and delta ( δ ) phase (Ni 3 Nb) during annealing. All deformed samples were also treated by aging and then annealing. The results show that the microstructure and component of δ phase dominated the recrystallization nucleation in the Ni-based alloy. Moreover, there was the presence of the δ phase interval limiting nucleation (PILN) and δ phase protecting nucleation (PPN), when a high content of close-set phase was precipitated from the matrix. The PILN determined the primary condition for the recrystallization nucleation that happended at the interval of δ phase larger than the critical nucleation size. The peak nucleation occurred in the PPN, where the recrystallization nucleus were free of the penetration by the adjacent grains, before the nucleation incubation time was reached. Thus, a new feasible J N theory was proposed to determine the maximum domain of recrystallization nucleation under close-set precipitated phases. All the possible nucleation sites were assumed under PPN in the J N theory. As such, the original microstructure can be expected to design for the annealing via the aging process. A quantitative evaluation of recrystallization nucleation can also achieved in the Ni-based alloys during aging.

Magnetostrictive bulk Fe-Ga alloys prepared by selective laser melting for biodegradable implant applications

Magnetostrictive Fe-Ga alloys have received extensive attention for their good mechanical properties and low saturation magnetization. However, the magnetostriction of bulk polycrystalline Fe-Ga alloys always suffers a major setback due to random grain orientation. In this study, selective laser melting (SLM) was used for the first time to manufacture bulk polycrystalline Fe81Ga19 alloys, and different scanning paths were determined for revealing the influences on grain orientation and magnetostrictive properties. The results showed that elongated columnar grains formed in the building direction due to the epitaxial growth during SLM. For zigzag scanning, grain orientation was parallel to the building direction while tilted by ∼17° for unidirectional scanning. And annular scanning resulted in mixed grain orientations in the alloys. Moreover, Fe81Ga19 alloy with zigzag scanning exhibited 〈100〉 preferred grain orientation. Consequently, the saturated magnetostriction of bulk Fe81Ga19 alloy with zigzag scanning reached ∼77.2 ppm, representing 23.9% and 25.1% increments compared with unidirectional and annular scanning, respectively. The Fe81Ga19 alloy with zigzag scanning also presented an ultimate compressive strength of 448.6 MPa and a degradation rate of 0.09 mm/y, as well as favorable biocompatibility. These results indicated that SLM might be a potential method for manufacturing magnetostrictive bulk Fe-Ga alloys for implant applications.

An innovative annealing treatment method and its mechanism to refine deformed mixed grains of initial aged GH4169 superalloy

The deformed mixed grains of the initial aged GH4169 superalloy need to be refined by annealing treatment. However, for the isothermal annealing treatment, the deformed mixed grains can only be refined to about 10 µm because the increase of nucleation rate needs to increase the temperature while the decrease of grain growth rate requires to decrease temperature. In the paper, an innovative method including an aging treatment and a subsequent continuous-cooling recrystallization annealing treatment (CC-RAT) is proposed. This method can not only increase the nucleation rate but decrease the grain growth rate. The effects of heat treatment parameters on microstructure are investigated. Besides, the grain refinement mechanism is studied using a developed cellular automaton (CA) model. The results show that the recrystallization takes place slowly during aging, while large number of δ precipitates appear. In subsequent CC-RAT, increasing starting temperature (Ts), decreasing cooling rate (V) or ending temperature (Te) can remarkably promote recrystallization, thereby refining grain microstructure. This attributes to the increase of recrystallization nucleation rate and the effective control of grain growth rate. In the early stage of CC-RAT, δ precipitates hinder the quick growth of recrystallized grains nucleated firstly. Moreover, the increase of Ts accelerates the nucleation rate, and the decrease of V prolongs the time for nucleation. Both of them promote the rapid formation of new recrystallized nuclei, especially at δ phase boundaries. As the annealing temperature decreases, newborn grains grow slowly, and these new grains restrict the growth of grains nucleated first. Therefore, a fine and uniform microstructure with an average grain size of 5.82 µm is obtained. However, when Ts is too high or V is too low, some coarse recrystallized grains appear. Hence, the feasible process is concluded as follows: aging treatment (900 °C×12 h), followed by CC-RAT (Ts = 990–1010 °C, V=1–2 °C/min, Te=950–970 °C).

Thermokinetics of shape recovery of nanostructured titanium nickelide

The microstructure, martensitic transformations (MTs), functional characteristics and thermokinetics of shape recovery of Ni-rich titanium nickelide was studied. Post-deformation annealing at a temperature of 823 K (30 min) after cold drawing with the accumulated logarithmic strain of 0.6 forms a mixed nano-sized grain / subgrain structure of B2 austenite. The training procedure was carried out using isothermal and non-isothermal bending modes. The loading-unloading temperatures were associated with the characteristic temperatures of MTs; the loading strain was varied in the range of 13 –19 %. The specific features of the evolution of functional characteristics when using various loading modes are described. The strain-temperature conditions for the realization of the total shape recovery 17 % and TWSME value 4 % are revealed. The two-stage character of shape recovery after unloading is revealed; the hypothesis of its origin is suggested. The start and finish temperatures of shape recovery vs loading strain are measured. When using the non-isothermal mode with deep cooling under load, the temperature range for shape recovery expands from 35 to 77 K with increasing loading strain. When using the isothermal mode with loading-unloading at a start temperature of the direct MT, the temperature range of shape recovery degrades from 66 to 54 K.

Hot deformation behavior and processing maps of BG801 bearing steel

The hot deformation behavior and processing maps of BG801 bearing steel were studied by isothermal compression test on temperatures ranging from 900 to 1150 °C and different strain rates varying from 0.01 to 2 s−1. The results showed that unstable regions with flow localization and microcrack appear on microstructure at low temperature and high strain rates. The mixed grain and large grain were observed at relatively high temperatures (1090–1150 °C) and low strain rates (0.01–0.05 s−1). The true stress-strain curves exhibit serrated flow behavior when the strain rates of 1 s−1 and 2 s−1. It may be due to the interaction effect of dislocation and solute atoms atmosphere such as the high content of Co and Mo element. Using the dynamic material modeling (DMM), the 3D processing map was constructed using flow stress data to reveal the hot workability. It reveals that the two available hot processing parameter ranges were at a temperature of 1060–1150 °C with a strain rate of 0.1–0.63 s−1 and 970–1080 °C with a strain rate of 0.01–0.23 s−1. However, the carbides in BG801 steel will dissolve in the matrix at a temperature of 1090 °C leading to a grain growth sharply and a poor mechanical property. Combine with the size of grain size and production processing, the most optimized processing conditions for BG801 steel can be defined as the temperature of 970–1080 °C and strain rate of 0.01–0.23 s−1.

Quantitative simulations of grain nucleation and growth at additively manufactured bimetallic interfaces of SS316L and IN625

This paper provides a quantitative understanding of grain nucleation and growth at the interface of SS316L and IN625 bimetallic structures during directed energy deposition (DED) through multi-physics simulations, including phase-field models and computational fluid dynamics analysis. The main finding is that the flow behaviors would lead to composition redistribution and the change of liquidus temperature in the mixing zone at the interface, which further influences the solidification sequence and the final grain structure that are different from general single-metal counterparts without the mixing zone. The results show that during depositing IN625 on SS316L, a gradual transition in composition distribution and liquidus temperature in the well-mixing zone caused by simple clockwise flow leads to epitaxial grain growth from the SS316L substrate and the prevalence of columnar grains with a low undercooling (<1 K) condition. However, when depositing SS316L on IN625, it turns out that initial solidification can occur due to abrupt compositional change at the interface where the well-mixing breaks are caused by two opposite (clockwise and counterclockwise) flow behaviors. Such an abrupt compositional change results in high liquidus temperatures that may trigger the grain nucleation in the middle melt pool due to a high undercooling (>30 K); thus, a mixed grain microstructure is present.

Effect of Temperature and Drying Time on Angiostensin Converting Enzyme (ACE) Inhibitor and Antioxidant Activity of Soybean (Glycine max L.)- Jackbean (Canavalia ensiformis L.) Mix Grains Tempeh Flour

The increase of hypertension sufferers encourage the development of functional foods. The presence of tempeh mixed grains of soybean and jackbean contains bioactive peptides as antihypertensive and antioxidant agents encourage the development of functional food such as tempeh flour of mixed grains. The research was aimed to investigate the effect of temperature and drying time on functional properties, asam amino acid profile, and isoflavone compounds. The different drying temperatures (50oC and 70oC) and drying time (6; 8; and 10 h) were applied on soybean and jackbean tempeh (1:1) w/w) for making the mixed grains tempeh flour. The Angiotensin Converting Enzyme (ACE) inhibitor activity, antioxidant activity, and total phenolic, amino acids profile, and isoflavone content of the flour were analyzed. The result showed that the best tempeh flour of mixed grains was obtained by drying at 70°C for 8 h with ACE inhibitor activity of 86.04%, antioxidant activity of 55.34% and total phenolic of 3.98 mg/g DB. This flour contained amino acids related to ACE-Inhibitor peptide precursors (glutamic acid and leucine), antioxidant peptide precursors (phenylalanine and histidine) as well as isoflavone compounds (daidzein and genistein). This finding reveals that drying temperature and time affected the functional properties, amino acids profile and isoflavone compounds.

Advancements in Shoreline Variation Prediction Considering Mixed Grain Sizes

Shoreline variations occurring in sea areas are caused by the combined effect of sediment transport due to the inflow and outflow of sediment caused by waves at the left and right boundaries of the sea area and the depth of movement limit. Although many studies have been conducted to understand the characteristics of sediment transport, assessment on valid sediment run-off supplied to the sea area from mountains and rivers in sea areas with river inflow and research on the sediment budget analysis considering the topographical characteristics of South Korean sea areas are insufficient. Therefore, the establishing mitigation measures considering comprehensive viewpoints is necessary to systematically respond to various natural and anthropogenic causes. Moreover, further research related to the setting and analysis of major parameters must be conducted for improving the prediction performance as well as the evaluation system for analyzing the sediment budget, which is a quantitative evaluation index for coastline management optimized for domestic waters. This study aimed to establish a comprehensive analysis system for analyzing the sediment run-off generated in domestic sea areas and develop a shoreline model (In-MPaS model) considering mixed grain sizes for advancing sediment run-off analysis. With the observation data, the parameters necessary for the numerical analysis were set, the sensitivity of the In-MPaS model according to the particle size distribution of the sediment constituting the sea area was evaluated, and the major parameters for improving the prediction performance were analyzed. Consequently, it was found that the prediction performance of the In-MPaS model improved in terms of valid sediment run-off as well as the sediments constituting the sea area (which was assumed to have mixed grain sizes rather than a single grain size(&lt;i&gt;D&lt;/i&gt;&lt;sub&gt;50&lt;/sub&gt;). In particular, considering the topographical properties that regulate sediment transport due to the island (Deokbong Mountain) at the foreside of the river mouth bar, the shoreline prediction performance was significantly improved with the application of groins, which exhibit structurally similar performance.

A Comparative Study on the Microstructures and Mechanical Properties of Al-10Si-0.5Mg Alloys Prepared under Different Conditions

Fabrication condition greatly influences the microstructures and properties of Al alloys. However, most of the available reports focus on a single fabrication technique, indicating there is still a lack of systematic comparisons among wider ranges of fabrication methods. In this paper, with conventional casting (via sand/Fe/Cu mold) and additive manufacturing (AM, via selective laser melting, SLM) methods, the effects of cooling rate (Ṫ) on the microstructures and mechanical properties of hypoeutectic Al-10Si-0.5Mg alloy are systematically investigated. The results show that with increasing cooling rate from sand-mold condition to SLM condition, the grain size (d) is continuously refined from ~3522 ± 668 μm to ~10 μm, and the grain morphology is gradually refined from coarse dendrites to a mixed grain structure composed of columnar plus fine grains (~10 μm). The eutectic Si particles are effectively refined from blocky shape under sand/Fe-mold conditions to needle-like under Cu-mold conditions, and finally to fine fibrous network under SLM condition. The tensile yield strength and elongation is greatly improved from 125 ± 5 MPa (sand-mold) to 262 ± 3 MPa (SLM) and from 0.8 ± 0.2% (sand-mold) to 4.0 ± 0.2% (SLM), respectively. The strengthening mechanism is discussed, which is mainly ascribed to the continuous refinement of grains and Si particles and an increase in super-saturation of Al matrix with increasing cooling rate.

Molecular dynamics study of oxygen-ion diffusion in yttria-stabilized zirconia grain boundaries

This work focuses on understanding the oxygen-ion transport through the mixed Grain Boundaries (GBs) present in yttria-stabilized zirconia (YSZ), a common solid oxide fuel cells (SOFCs) electrolyte.

ВЛИЯНИЕ ТЕХНОЛОГИЧЕСКИХ И ХЛЕБОПЕКАРНЫХ ПОКАЗАТЕЛЕЙ СОРТОВ ТВЕРДОЙ ПШЕНИЦЫ НА ЭФФЕКТИВНОСТЬ СМЕШИВАНИЯ С МЯГКОЙ ПШЕНИЦЕЙ

The use of non-traditional types of raw materials is an important direction in the baking industry, which allows expanding the range of bakery products. These types of raw materials include grain - durum wheat. The purpose of the research is to evaluate, based on the results of technological and baking evaluation, the effectiveness of mixing grain flour of various varieties of durum wheat and soft wheat flour. The technological parameters of grain, the rheological and physical parameters of the dough, the general baking assessment were studied, and it was found that the high gas-forming ability of durum wheat allows it to be used up to 30% as an improver for soft wheat during baking. However, a positive effect was not observed in all years of the study. The effect of improvement due to the mutual compensation of the missing components and the complementarity (mutual complementarity) of soft and durum wheat varieties has been established. It was found that in 2015 the largest volume of bread 920-980 cm3 and a high baking grade (smooth surface, oval shape, golden brown color of the crust, as well as fine thin-walled porosity with an elastic light crumb) were obtained by adding durum varieties to soft wheat. , which in the year of the study formed a weak gluten (thinning of the dough 110-130 f.f., valorimetric estimate - 46-54 w.u.). In 2020, the varieties used in composite mixtures of both spring soft and durum wheat had high quality in terms of baking assessment both in control (Tulaikovskaya 108 - bread volume 1300 cm3) and in mixtures of 1140-1255 cm3. The appearance of bread and crumb in almost all variants had a five-point rating. The use of the optimal amount of durum wheat flour (30:70%) when baking bread reduces its staleness by 6.5% relative to the control (soft wheat), the bread remains fresh for a long time with an elastic, quickly restored crumb.

Comprehensive exergy transfer analysis of a cyclonic furnace integrated recirculating mixed flow grain dryer

Investigation of exergy transfer is an important aspect for all grain drying industry. Exergy transfer of rice husk fired cyclonic furnace assisted recirculating mixed flow dryer (MFD) equipped with a heat exchanger, was sought in this study. A cyclonic furnace (CF) having capacity 0.5 MW and recirculating MFD were designed and developed to investigate exergy transfer during grain drying. Efficiency of furnace was determined to quantify performance of CF for industrial grain drying system. Exergetic efficiency was also thoroughfare performed for the developed CF, air mixing chamber (heat exchanger) and MFD. Thermal efficiency of the CF varied from 68.96 to 87.01% during drying of high moisture maize grain. Exergy efficiency of the CF, heat exchanger and drying chamber marked between 58.8 and 63.5%, 74.6–93.29%, and 3.03–21.9%, respectively. Exploration of exergy inflow persist between 53.32 and 60.51 kJ/s and 7.58 to 9.81 kJ/s while exergy outflow ranged between 7.58 and 9.81 kJ/s and 1.52 to 3.10 kJ/s, respectively for heat exchanger and drying chamber. Results based on exergy losses indicates that 44.01–51.54 kJ/s and 5.87–7.50 kJ/s of exergy is just loss through heat exchanger and drying chamber, respectively. Exergy improvement potential and sustainability index varied between 1.02 and 1.80 kJ/s and 1.17–1.40 kJ/s, respectively. Quality of final product is in acceptable range as color difference of dehydrated maize kernel varied from 9.19 ± 0.46 to 17.05 ± 0.13. Exergy results indicate that CF can aptly be applied for grain drying industry in commercial scale.