Ar Gas Flow Rate Research Articles

Multi-response optimization of process parameters of GMA welding of dissimilar AA 6061-T6 and AA 5083-O aluminium alloy for optimal mechanical properties

The sufficient tensile strength and hardness are important parameters to decide soundness of the joint; that is dependent on the welding parameters. The influence of welding parameters of gas metal arc (GMA) welding on mechanical properties (tensile strength and hardness) of the joint of dissimilar aluminium alloys 6061-T6 and 5083-O has been investigated. A mathematical model is developed to predict tensile strength and weld hardness of the joint. Response surface methodology is applied in the study. Three factors (welding current, welding voltage and gas flow rate), three levels and rotatable central composite design with full replications technique was used. The results indicate that welding current has the greater impact on tensile strength and weld hardness of the joint; followed by welding voltage and gas flow rate. Tensile strength and weld hardness are increasing with increase in welding current. Welding voltage and gas flow rate have negative effect on tensile strength and weld hardness. The optimum welding parameters is investigated to maximize tensile strength and hardness of the joint under the constraint of used GMA welding machine. A welding current of 182 Amp, welding voltage of 20 V and Ar gas flow rate of 17 lit/min are found optimum welding process parameters.

Optimization of weld strength for laser welding of steel to PMMA using Taguchi design method

Dissimilar joining of 304 stainless steel to PMMA is accomplished by a Nd: YAG pulsed laser. The light and process were represented by laser peak power, welding speed, defocus, pulse duration, pulse frequency and Ar gas flow rate, as these experiment parameters have significant effects on joints strength, weld width, joints quality and appearance. The welding parameters were optimized by an orthogonal experiment design, then the validation and optimization experiments were carried out to obtain the best combination of process parameters. A maximum weld strength of the joints of 974 N was achieved (the joints efficiency reached 70% of the base PMMA), much larger than ever reported. Bead profiles such as bead width and mechanical strength were investigated, and five types of 304 stainless steel-PMMA welded joints and three kinds of fracture model have been proposed.

Flow study in structure of the plasma torch for microwave plasma spray

Microwave oven induced plasma method is a novel application of microwave oven to generate plasma for coating process. It uses 2.45 GHz microwave power and only 0.8 kW input power to produce the plasma which capable of spraying all materials that are considered sprayable. However, the research regarding this microwave plasma spray are more to be discovered. Suitable structure of plasma torch is needed for microwave plasma spray that can produce laminar flow to produce desire plasma for coating application. Therefore, this paper will discuss about the suitable structure of plasma torch needed for laminar flow by Reynolds number calculation. Reynolds number calculated by applying the outlet diameter of antenna which is 2, 3 and 4 mm. From this research, Reynolds number from all outer diameter of antenna are below 2000 which indicate laminar flow. The widest plasma diameter achieved at 6.59 mm with 4 mm outlet diameter of antenna and 15 lpm working gas flow rate while the narrowest plasma diameter achieved at 1.26 mm with 3 mm outlet diameter of antenna and 10 lpm flow rates of working gas. The most acceptable condition for producing plasma plume was at 3 mm of antenna diameter with 25 lpm of Ar gas flow rates.

Electrical and optical properties of Ga-doped ZnO thin films deposited by DC magnetron sputtering

The electrical and optical properties of Ga-doped ZnO (GZO) thin film prepared by direct current (dc) magnetron sputtering were investigated. The GZO thin film was deposited on a glass substrate at a substrate temperature (Ts) of room temperature (RT), 150 °C, and 200 °C using DC power of 100 W and an Ar gas flow rate of 450 sccm. The thickness of films was maintained at about 200 nm by controlling the deposition rate of about 12.5 nm/minute. The result showed that the electrical properties improved with increasing Ts. The films deposited at Ts of 200 °C showed the lowest resistivity, highest hall mobility, and carrier concentration compared to other Ts. The average transmittance of the films in the visible range (380-750 nm) was approximately 86.04%. The value of the optical band gap (Eg) was approximately 3.8 eV. The results suggested that GZO films deposited by DC magnetron sputtering at Ts of 200 °C can be applied to transparent conducting oxide (TCO) as an electrode in optoelectronic applications such as solar cells, LEDs and display technology.

Synthesis of TiN, Ti, and TiSi2 Thin Films for the Contact System of Solar Cells

The influence of deposition parameters, such as: the magnetron power in the range 690–1400 W, the silicon substrate temperature 23–170°C, the N2 gas flow rate 0.9–3.6 L/h, the Ar gas flow rate 0.06‒3.6 L/h, the ratio of N2/Ar gas flows 1–60 on the thickness, the density, and the composition of the deposited films is analyzed. The maximum density 5.247 g/cm3 corresponding to the TiN0.786 = Ti56N44 composition has been achieved at the following deposition parameters: 1200 W, N/Ar = 1.8/0.06 L/h = 30, 0.8 Pa, 320 s, and 100°C. At temperatures 700–800°C, the mutual diffusion of titanium and silicon atoms through the interface leads to the active nucleation, the formation of nanocrystals and low-resistance metallization layers. X-ray diffraction shows that, during annealing at 700°C (30 min, Ar), the formation of phase TiSi2 due to the diffusion of Ti atoms into silicon is twice more intense than the formation of Ti5Si3 due to the diffusion of silicon atoms into titanium as a result of high hardness of titanium. The average sizes of TiSi2 decreases from 7.1 to 5.6 nm at 750°C due to the crystallization of the nuclei and increase to 9.2 nm at 800°C.

Синтез тонких пленок TiN, Ti и TiSi-=SUB=-2-=/SUB=- для контактной системы солнечных элементов

Abstract The influence of deposition parameters, such as: the magnetron power in the range 690–1400 W, the silicon substrate temperature 23–170°C, the N_2 gas flow rate 0.9–3.6 L/h, the Ar gas flow rate 0.06‒3.6 L/h, the ratio of N_2/Ar gas flows 1–60 on the thickness, the density, and the composition of the deposited films is analyzed. The maximum density 5.247 g/cm^3 corresponding to the TiN_0.786 = Ti_56N_44 composition has been achieved at the following deposition parameters: 1200 W, N/Ar = 1.8/0.06 L/h = 30, 0.8 Pa, 320 s, and 100°C. At temperatures 700–800°C, the mutual diffusion of titanium and silicon atoms through the interface leads to the active nucleation, the formation of nanocrystals and low-resistance metallization layers. X-ray diffraction shows that, during annealing at 700°C (30 min, Ar), the formation of phase TiSi_2 due to the diffusion of Ti atoms into silicon is twice more intense than the formation of Ti_5Si_3 due to the diffusion of silicon atoms into titanium as a result of high hardness of titanium. The average sizes of TiSi_2 decreases from 7.1 to 5.6 nm at 750°C due to the crystallization of the nuclei and increase to 9.2 nm at 800°C.

Plasma Treatment of Polymer Powder as an Effective Tool to Functionalize Polymers: Case Study Application on an Amphiphilic Polyurethane.

Plasma treatment is a widely applied, easy, fast, and highly reproducible surface modification technique. In this work powder plasma treatment was exploited to expose carboxylic groups along the backbone of a water soluble polymer. Specifically, a custom-made amphiphilic poly(ether urethane) containing Poloxamer® 407 blocks (Mw = 54,000 Da) was first synthesized and its powders were plasma treated in the presence of Acrylic Acid vapor. To maximize –COOH group exposure while preventing polymer degradation, different Ar gas flow rates (i.e., 10, 30, and 50 sccm) were investigated. Upon gas flow increase, significant polymer degradation was observed, with a 35% molecular weight reduction at 50 sccm Ar flow rate. On the other hand, the highest number of exposed carboxylic groups (5.3 × 1018 ± 5.5 × 1017 units/gpolymer) was obtained by setting gas flow at 10 sccm. Hence, a gas flow of 10 sccm turned out to be the best set-up to maximize –COOH exposure while preventing degradation phenomena. Additionally, upon plasma treatment, no detrimental effects were observed in the thermoresponsiveness of polymer aqueous solutions, which was ensured by Poloxamer® 407 blocks. Therefore, the newly developed technology here applied on an amphiphilic poly(ether urethane) could pave the way to the tailored design of a plethora of different multifunctional hydrogels.

Decolorization of Amaranth aqueous solution by atmospheric-pressure plasma jet irradiation

The decolorization of Amaranth aqueous solution by irradiation with an atmospheric-pressure plasma jet was examined by absorbance spectrum measurement and nuclear magnetic resonance (NMR) and mass spectrometry (MS) analyzes. An atmospheric-pressure argon (Ar) plasma jet was generated at a frequency of 10 kHz with an applied voltage of 10 kV and an Ar gas flow rate of 10 l min−1. When 10 ml of 100 mg l−1 Amaranth aqueous solution was irradiated with this plasma jet, the red solution gradually became lighter with increasing irradiation time and was almost completely decolorized after 70 min of irradiation. The results of NMR and MS analyzes indicated that the decolorization was caused by the destruction of the azo bond in the Amaranth molecules.

Parameters Affecting the Antimicrobial Properties of Cold Atmospheric Plasma Jet.

Using the Taguchi method to narrow experimental parameters, the antimicrobial efficiency of a cold atmospheric plasma jet (CAPJ) treatment was investigated. An L9 array with four parameters of CAPJ treatments, including the application voltage, CAPJ-sample distance, argon (Ar) gas flow rate, and CAPJ treatment time, were applied to examine the antimicrobial activity against Escherichia coli (E. coli). CAPJ treatment time was found to be the most influential parameter in its antimicrobial ability by evaluation of signal to noise ratios and analysis of variance. 100% bactericidal activity was achieved under the optimal bactericidal activity parameters including the application voltage of 8.5 kV, CAPJ-sample distance of 10 mm, Ar gas flow rate of 500 sccm, and CAPJ treatment time of 300 s, which confirms the efficacy of the Taguchi method in this design. In terms of the mechanism of CAPJ’s antimicrobial ability, the intensity of hydroxyl radical produced by CAPJ positively correlated to its antimicrobial efficiency. The CAPJ antimicrobial efficiency was further evaluated by both DNA double-strand breaks analysis and scanning electron microscopy examination of CAPJ treated bacteria. CAPJ destroyed the cell wall of E. coli and further damaged its DNA structure, thus leading to successful killing of bacteria. This study suggests that optimal conditions of CPAJ can provide effective antimicrobial activity and may be grounds for a novel approach for eradicating bacterial infections.

Controlled synthesis of large scale continuous monolayer WS2 film by atmospheric pressure chemical vapor deposition

Synthesis of monolayer transition metal dichalcogenides (TMDs) in large-size is crucial to their practical applications in electronics and optoelectronics. Here, large scale continuous monolayer WS2 film has been successfully grown by atmospheric pressure chemical vapor deposition (APCVD) method. By modulating three growth parameters, Ar gas flow rate, the temperature of WO3 precursor and the distance between substrate and WO3 precursor, WS2 film with different grain size can be obtained. At optimal processing condition, large-scale monolayer WS2 with lateral dimension can reach 1 mm above. This would pave the way for scale production of continuous monolayer TMDs film.

Factors Influencing Hardness of a Coating Material for Coating a Machine Component

This work investigated the influences of DC current, pressure and N2 to Ar gas flow rate on hardness of a TiN hard coating material for coating a fishing net-weaving machine component of a fishing net-weaving machine, namely upper hook. The target of this study was to maximize the hardness of TiN coated upper hook in order to maximize the corresponding wear resistance. Three process factors including DC current, operating pressure and N2 to Ar flow rate ratio were simultaneously investigated using the factorial design with replicates at the center point of the three factors method. Analysis of variance was used to investigate the effect of the three factors on the hardness of the TiN coated upper hook and the contour plots based on empirical model were plotted to obtain an appropriate operating condition of the statistically significant process factors with maximizing hardness value leading to the wear resistance of the upper hook. The results showed that the operating pressure and the N2 to Ar flow rate ratio and interaction among the three process factors significantly affected the average hardness at the level of significance of 0.05. Finally, an appropriate operating condition of the significant process factors was obtained at the higher levels of the operating pressure and the N2 to Ar flow rate ratio.

Mechanism and optimization of non-thermal plasma-activated water for bacterial inactivation by underwater plasma jet and delivery of reactive species underwater by cylindrical DBD plasma

Plasma-activated water (PAW) has been in use for the past decade in sanitization against bacteria and other microorganisms. This research study compared PAW generated by a DC positive flyback transformer (FBT) underwater plasma jet with delivery of reactive species underwater by cylindrical dielectric barrier discharge (C-DBD) with a neon transformer. A Box–Behnken design was adopted as a response surface methodology (RSM) to design the experimental plan and optimize operating parameters including time, gas flow, and gas ratio. The physical responses comprise optical emission spectroscopy (OES), pH, oxidation-reduction potential (ORP), and electrical conductivity (EC). The chemical responses consist of hydrogen peroxide (H2O2) and hydroxyl radicals (OH·). The biological responses include Escherichia coli reduction and Staphylococcus aureus reduction. The optimal condition for underwater plasma jet was found to be Ar gas with a flow rate of 3 slm for 6.5 min of treatment time, which can reduce E. coli and S. aureus to 7.14 ± 0.14 and 3.10 ± 0.26 in log, respectively. Also, the optimal condition for delivery of reactive species underwater by C-DBD plasma was found to be Ar (99%): O2 (1%) gas mixture with an Ar gas flow rate of 4 slm for a treatment time of 11.5 min, which could reduce E. coli and S. aureus to 0.45 ± 0.07 and 2.45 ± 0.23 in log, respectively.

Morphology Changes of Amorphous-SiO x Thin-Film Negative Electrodes of Different Oxygen Contents

The silicon–oxygen binary system (SiO x ) has attracted attention as a negative electrode with a reasonably high energy density and good cyclability. The oxygen-content dependence of the reversible capacity and cycle performance of SiO x electrodes have been reported.1,2 However, effects of oxygen content on morphology changes in SiO x electrodes upon cycling have not been clarified well in spite of their importance in understanding the capacity fading mechanism, and to improve the cycle performance of SiO x electrode. Therefore, we investigated the cycle performance and morphology changes in SiO x films with various oxygen contents. SiO x thin films were prepared by RF magnetron sputtering on oxygen-free Cu foil, in which the deposited masses of Si were constant. The flow rate of Ar gas was fixed at 20 sccm, while that of O2 gas was varied in the range of 0-0.20 sccm to change the oxygen content in SiO x . The RF power and processing pressure were optimized to obtain amorphous SiO x films without any crystalline phases. After deposition, the SiO x film was transferred to an Ar-filled glovebox without exposure to air, and a coin-type half-cell was assembled. Solutions of 1 M LiPF6 dissolved in a mixture of ethylene carbonate (EC) and diethyl carbonate (DMC) (3:7 by vol.) with and without 10 wt.% VC were used as electrolytes. O/Si atomic ratio was determined from energy dispersive X-ray spectroscopy (EDX) analysis. The discharge capacity of lightly O-doped SiO x films (x = 0.21 and 0.48) did not change appreciably compared to that of pure-Si film, meaning that almost all Si atoms in the SiO x film contributed to the Li alloying/dealloying reactions. The cyclability of the lightly O-doped SiO x films was improved little. On the other hand, an irreversible fraction of Si in SiO x at high oxygen contents (x = 1.09 and 1.78) increased owing to the formation of an inactive Li4SiO4 phase.3 In return for the decrease of reversible capacity, the capacity retention of the heavily O-doped SiO x films improved owing to the buffer effect of Li4SiO4 matrix against volume changes. Moreover, the capacity retention of the SiO x films was improved substantially by VC addition, especially for the heavily O-doped SiO x films. The morphology changes with cycling in the SiO x films were affected significantly by the oxygen content and presence of VC. For the pure-Si film, a sponge-like porous structure appeared after cycling owing to repeated crack formation and inhomogeneous volume changes, and resulted in massive electrode swelling. For the heavily O-doped SiO x films, the morphology change was suppressed by the volume buffer of Li4SiO4 matrix. We found that a relatively high oxygen content is required to obtain a stable Li4SiO4 phase because SiO x decomposes to LiO2 and Li-Si alloy in the lightly O-doped SiO x . The morphology change was further suppressed by VC addition because the thin and uniform SEI layer derived from VC inhibited the electrolyte decomposition and allowed for uniform Li alloying/dealloying. The volume buffer of Li4SiO4 and the uniform SEI are important to achieve a long-term cycle life of SiO x negative electrode for lithium-ion batteries.

Mathematical model for decarburization of ultra-low carbon steel during RH treatment

ABSTRACT A mathematical model was established to investigate the decarburization behaviour of ultra-low carbon steel during Ruhrstahl-Heraeus (RH) refining process. In this model, it was assumed that the decarburization reactions occur at four sites: Ar bubble surface, bath surface, bulk steel and splash droplet surface. The effect of Ar bubble behaviour and splash droplet behaviour on decarburization rate was taken into consideration specifically. The calculated results are basically consistent with the industrial experimental observations. Carbon concentration was mainly eliminated at bath surface at early stage of RH treatment, and was mostly removed in bulk steel at middle stage, and was removed at splash droplet surface in the final stage. The decarburization rate at different sites and its contribution to total decarburization value were evaluated in detail. The decarburization rate during RH treatment could be effectively improved by accelerating the drop of vacuum pressure at early stage. Appropriate increasing Ar gas flow rate was beneficial to deep decarburization by increasing the reaction area of droplet surface and bath surface.

Effect of plasma jet on the water and hydrogen peroxide that used for assisted teeth bleaching

In this work the interaction of plasma jet with water and hydrogen peroxide liquids used for assisted teeth bleaching by plasma jet had been study. A homemade plasma jet system was used. The plasma jet supply by 15 W electrical power generated by high voltage power supply of 9.6 kV peak to peak and frequency of 33 kHz .this power supply generate high electric field on electrodes that would be enough to ionize the argon gas. Some important agents were study such as the effect of the Ar gas flow rates on the length of the plasma jet, the influence of plasma jet on some properties of water and two hydrogen peroxide concentrations 25 % and 30 % like pH, conductivity and liquid temperature for different exposure time. The liquids temperature was measured by digital infrared thermometer, the gas flow rate were measured by gas flow meter, the pH, and the conductivity was measured by pH conductivity ultra-meter. The results illustrated that the conductivity and liquid temperature increase with increasing of exposure time. It can be conclude that the liquid properties were changed less than the boundaries that could affect adversely to the cells that located in the plasma jet.

Behaviour of Hydrogen in Industrial Scale Steel Melts

The behaviour of hydrogen during controlled industrial scale secondary steel making process has been examined in a variety of low alloy steels, sensitive to hydrogen flaking. The study examines the role played by the moisture in input raw materials such as the ferro-alloys, type of carbon additive and fluxes in enhancing the hydrogen content in the ladle furnace. Post alloying, the influence of vacuum degassing parameters such as the vacuum level, vacuum holding time, Ar flow rate, type of porous plug used, slag chemistry and the steel grade was examined. The vacuum degassing process was analysed using a kinetic model, which could justify the trends seen in the vacuum level, holding time and Ar gas flow rate. Finally, the hydrogen pick-up post vacuum degassing through slag cover and the casting tundish was found to be influenced by parameters such as the quality of the tundish spray mass, and casting sequence. The influence of steel grade in hydrogen removal was also examined.

Formation of Titanium Hydride from the Reaction Between Magnesium Hydride and Titanium Tetrachloride

The reaction between magnesium hydride (MgH2) and titanium tetrachloride (TiCl4) to produce titanium hydride (TiH2) was carried out at varying temperature, time and Argon (Ar) gas flow rate. The reaction conditions were optimized for increasing the formation of TiH2 by using the statistical design of experiments (DOE). The hydriding temperature was varied from 200 to 300 °C, while the reaction time was changed from 60 to 180 minutes. The flow rate of argon gas was controlled in the range of 20 to 60 mL.min−1 to minimize TiCl4 dilution. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Elemental hydrogen analyzer. From the experiments, the highest weight change (Xw) of the sample produced at 300 °C for 180 minutes with Ar flow rate of 20 mL.min−1 was 0.19 wt.% and the degree of hydriding (Xh) of 38.49% by elemental hydrogen analysis. The DOE analysis inferred that the reaction time was the most significant factor followed by the flow rate of Ar gas and reaction temperature. The SEM/EDX analysis indicated that the product was composed of MgH2, MgCl2, TiCl2.3 and TiH2.The product contained a minor phase of TiO2 that could be due to seepage of ambient moisture into the reaction chamber.

Synthesis and Characterization of Novel Multipods-Branched Cd-Se-S Micro-/Nano-Structures

Novel multipods-branched Cd-Se-S micro-/nanostructures (MNSs) were successfully prepared in a tube furnace by thermal evaporation under atmospheric pressure through using high-purity CdS and CdSe mixture powder with a molar ratio of 1:1 as evaporation source, high-purity Ar gas as carrier and protective gas, and mica wafer as substrate. Under the optimum condition, the evaporation temperature was 1100 °C, Ar gas flow rate was 200 sccm, and the distance between the evaporation source and substrate was 22 cm. The microstructure examination revealed that the length of the obtained branches was up to tens of microns and the diameter of the branches was of a few microns. The composition and crystal structure analyses indicated that, the chemical composition of the multipods-branched Cd-Se-S MNSs was CdSe0.86S0.14, which had a hexagonal structure and good crystallinity. The photoluminescence spectrum at room temperature displays an intrinsic emission peak around 620 nm. In addition, their growth might be controlled by a vapor-solid mechanism.

Melting and Crystallization of Amorphous Germanium Films on Insulating Substrate By Atmospheric Pressure Micro-Thermal-Plasma-Jet

Fabrication of complementary metal oxide semiconductor (CMOS) on interlayer dielectric films is important to realize 3-dimentional (3D) integration which are promising for higher integrity beyond the scaling limits. Because of the high carrier mobility compared to that of silicon (Si), crystalline-germanium (c-Ge) is very attractive as a new channel material for 3D devices. In this work, rapid melting and crystalline growth of amorphous germanium (a-Ge) thin films on insulating substrate induced by atmospheric pressure micro-thermal-plasma-jet (μ-TPJ) irradiation have been investigated. 80 to 150-nm-thick a-Ge films were formed on quartz substrate by plasma enhanced chemical vapor deposition (PECVD) using GeH4 and H2 at 200 °C. Phosphorus (P) ion implantation at the doses up to 5.0×1015 cm-2 (100 keV) was performed to some samples and then the films were dry etched to form strips with the width of 2 mm. After 550 nm SiO2 capping layer deposition by remote-PECVD, μ-TPJ was irradiated under atmospheric pressure with supplying power (P) of 0.8-1.1 kW, Ar gas flow rate (f) of 1.0 L/min, and scanning speed (v) of 600-1800 mm/s to perform crystallization and impurity activation simultaneously. The distance between the plasma source and substrate (d) was set at 2.0 mm. After formation of contact holes, Al electrodes were formed by vacuum evaporation and TiN electrodes were formed by sputtering to compare contact characteristics. The shape and the grain boundaries (GBs) of these Ge patterns were investigated by scanning electron microscope (SEM) and electron backscattering diffraction (EBSD) method. Crystallized Ge films showed intrinsic p-type conduction when no doping to the samples was performed. They showed good Ohmic contacts with Al, and hole concentration of ~1×1018cm-3 and mobility of ~100 cm2V-1s-1 were observed in samples with small grain size. By performing lateral crystallization and obtaining large grain, the hole concentration significantly decreased to 5.2×1016 cm-3, and a high hole mobility of 1070 cm2V-1s-1 were obtained. These results suggest that defect induced hole generation was significantly suppressed by enlargement of grain size in Ge strips. Thin film transistors fabricated under the same crystallization condition showed a high on/off ration of 1.4×104 and a mobility of 196 cm2V-1s-1. Small field effect mobility compared with bulk mobility is attributed to the poor interfacial quality between SiO2/Ge. In the case of heavily-phosphorus-doped and μ-TPJ crystallized Ge films, we obtained good Ohmic contacts not only by TiN electrodes, but by Al electrode also. We obtained a high electron concentration of 2.0×1020 cm-3 and mobility of 150 cm2V-1s-1, respectively. The efficiency of activated electron conc. / phosphorus conc. reached 54 %, and this high efficiency activation achieved good Ohmic contacts irrespective of electrode metal. EBSD images of the crystallized Ge, the maximum grain size was 28 µm in length and most of the GBs showed Σ3 coincidence site lattice (CSL). By decreasing the phosphorus doping concentration, the mobility increased markedly as shown in the graph. Although there exist large scatter in mobility values, a highest electron mobility of 2720 cm2V-1s-1 has been obtained so far. μ-TPJ is a promising method for formation of high quality Ge crystalline films on insulating substrate. Figure 1

Non-thermal plasma for elimination of pesticide residues in mango

Abstract The effects of non-thermal plasma (NTP) on elimination of pesticide residues and on quality changes of mango (cv. Nam Dok Mai) were investigated. Varied flow rate of Ar gas (2, 5 and 8 L/min) and time dependent degradations of chlorpyrifos and cypermethrin as a result of NTP treatments using a gliding arc (GA) discharge for 5 or 10 min were studied. Results showed that the NTP treatment for 5 min at 5 L/min Ar flow rate successfully decreased the concentrations of chorpyrifos by 74.0% and cypermetrin by 62.9%. There were significant (p ≤ 0.05) decreases in titratable acidity and total phenolic content and increases in carotenoid content for the treated mangoes. However, total soluble solid, color and texture parameters were not significantly different (p > 0.05). The emission signal of hydroxyl (OH ) radicals at 309 nm was also obtained to monitor that the system was working properly. Industrial relevance This study demonstrates the potential application of non-thermal plasma (NTP) as a way to eliminate pesticide residues and on quality changes in mango. A varied flow rate of Ar gas and time dependent degradation of chlorpyrifos and cypermethrin were studied for NTP treatments produced using a gliding arc (GA) discharge. Our results have proved that the GA discharge NTP has the potential to be an effective method to ensure chemical safety not only for mangoes, but also for other types of postharvest produce. This system can be adapted for the industrial up-scale.