In the present study, the mechanical properties and high-temperature sliding wear behaviour of the Al6082-SiC-TiO2 hybrid composite in different environmental conditions produced by the stir-casting process were investigated and distinguished with single-reinforced composites (Al6082-SiC and Al6082-TiO2) and matrix alloy. The microstructure of composites exhibited a reasonably uniform scatter of particles in the aluminium matrix with good bonding between the matrix-particle interfaces. The hybrid composite’s hardness and ultimate tensile strength showed higher hardness and tensile strength than matrix alloy and single-reinforced composites, whereas trends were reversed for the elongation. The impact test of the materials was conducted at different temperatures (room temperature, 0°C, –25°C, –50°C, and –75°C). The hybrid composite shows higher impact strength than the other materials, and impact strength decreases with temperature because ductility decreases with temperature. The fracture surfaces were examined to identify the fracture mechanism. The sliding wear test was conducted at different temperatures (room temperature, 100°C, 175°C, 250°C and 325°C) to distinguish the tribological behaviour of materials. The weight loss of the materials was increased with an increase in temperatures. The hybrid composite shows a lower weight loss than the other condition samples, irrespective of the temperatures. The wear surfaces were examined to predict the material removal mechanism.

Due the importance of using commercially Zamak5 in a wide range in industrial applications, however, this study was focused on the enhancing its machining issues by adding pure copper, so the effect of the addition of (1 to 3)% Cu to commercially Zamak5 on its mechanical properties, microhardness, surface texture and corrosion resistance was investigated. A CNC machining tests, microhardness tests, corrosion test, compression test, and microhardness test were performed. It was found that there is an enhancement on the flow stress at 0.2 strain of about 19% for 3% Cu addition followed by 17% and 15% in the case of 2% Cu and 1% Cu respectively. There was an enhancement in microhardness of about 11.6% in the case of 3% Cu addition. The surface finish was improved by increasing the number of copper contents (1 to 3)% to the base material Za5. Polarization measurements revealed that 3% alloy specimen inhibit the corrosion by more than 70% compared with the blank sample.

Lubrication and heat transfer control are two significant functions of mold fluxes. In order to coordinate the contradiction between lubrication and heat transfer, the effects of BaO and Li2O on basic characteristics of CaO-SiO2 based mold fluxes were studied by hemispherical melting temperature instrument, rotating cylinder method, X-ray diffractometer (XRD) in present study. The results show that the melting temperature and viscosity at 1300°C all represent a downward trend with BaO and Li2O enhancement at different basicity, and the break temperature decrease with BaO addition while decrease and then increase with Li2O addition, which illustrates that Li2O content should be no more than 0.8 wt% for the purpose of lubrication. Meanwhile, to ensure a sufficient thickness of the liquid slag film and avoid discontinuity of the liquid slag film, the BaO content is better to be 10 wt% with low melting temperature and viscosity. The main crystalline phase in the mold fluxes is cuspidine (3CaO·2SiO2·CaF2), and the crystallization ratio rises sharply when basicity increased to 1.65. For better deal with the contradiction of lubrication and heat transfer, the mold fluxes composition w(BaO) = 10 wt%, w(Li2O) = 0.8 wt%, R ≥1.65 is reasonable, which has a profound impact on high crystallization and lubricity mold fluxes.

Donghua steel continuous casting-rolling (DSCCR) line is a new endless rolling line in which tunnel heating furnace is added before and after roughing mills to change the temperature field of slab and intermediate slab, but this change will affect the microstructure and properties of hot rolled plate. Therefore, the microstructure evolution, mechanical properties, texture analysis, hole expanding and earing test of 2.0 mm thick hot rolled plate produced by DSCCR line at different final rolling temperature of 860°C, 840°C and 820°C are studied. The results show that with the decrease of final rolling temperature, there is an obvious layered microstructure distribution along the thickness direction, and the surface coarse grain area gradually expands inward, at the same time the morphology of cementite also changed from large multi domain lamellar pearlite and long rod cementite to small single domain lamellar pearlite and short rod cementite. The engineering stress-strain curves have discontinuous yield with the yield elongation of 4-5% and the elongations are more than 35%. EBSD analysis shows that small angle grain boundaries and deformed grains increase significantly with the decrease of final rolling temperature, and are mainly distributed in fine grain area. Hole expanding and earing tests show that with the decrease of final rolling temperature, the earing performance decreased but the limiting hole expanding ratio is similar.

The article considers the method of obtaining reinforced castings from gray cast iron by lost foam casting. The aim of this study was to determine the microstructure formation of gray cast iron reinforced with inserts of carbon and stainless steel in this casting method. The results of the research have shown that the products of destruction of expanded polystyrene have a positive effect on the bonding formation of cast iron with reinforcing inserts. When steel wire is used as reinforcement, a decarbonized layer of cast iron is being formed around it, in which the inclusions of graphite are smaller and their quantity is less than in the main metal. Due to carburization, the surface structure of the reinforcement changes from ferrite to pearlite with cementite. Steel wire reinforcement can be effective in increasing strength and toughness of gray cast iron. The usage of stainless steel reinforcement leads to the formation of a transition layer on the part of the matrix metal. It contains ledeburite with dissolved chromium, which increase the wear resistance of cast iron.

Mn-Al alloys are important alloys due to their magnetic properties and have been identified as permanent magnets. This alloy possesses magnetic properties and can be manufactured at a relatively low cost. Mn-Al alloys could be an alternative to rare earth magnets and hard ferrites and have a promising future. In this study, the effects of sintering temperature, holding time and pressure on densification, average grain size and magnetic properties of the SPS-ed Mn-Al alloys were observed. However, with the different sintering parameters, the magnetic phase τ phase could be achieved. To obtain the τ phase, different annealing methods were tried, yet samples heated to 650°C and air cooled exhibited magnetic properties. This sample was selected from various sintering parameters due to its high density of 99% N6 (800°C – 300 sec – 60 MPa) and has an average grain size of 137±18.1 µm. The uniqueness of this work is that statistical approaches such as Taguchi design of experiment (DOE) and regression were used for optimization of the manufacturing process.

The phase transformation dynamic and electrical conductivity equations of the aged Cu-2.7Ti-2.5Ni-0.8V alloy were established in this work. The microstructure evolution and precipitated phases were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mechanical properties were tested using a hardness testing machine and universal test machine, and the electrical conductivity was measured by the eddy conductivity gauge. The results show that NiTi intermetallic compounds are formed during the solidification, and these phases such as Ni3Ti and NiV3 are precipitated after aging treatment. The fracture morphology displays that a large number of shallow and equiaxed dimples occur on the tensile fracture, indicating a typical ductile fracture. After aging treatment at 450°C for 240 min, the hardness, tensile strength, elongation and electrical conductivity of the Cu-2.7Ti-2.5Ni-0.8V alloy are 184 HV, 459 MPa, 6.3% and 28.72% IACS, respectively.

Arsenic is the only beneficial impurity for copper electrorefining through inhibiting anode passivation and the formation of floating slimes. The behaviour of copper anodes with different content of arsenic were studied at high current density (>280 A/m ²). It showed that low arsenic anodes (As < 300 ppm) easily generated anode passivation, floating slimes and cathode nodules during the electrorefining proccess. The floating slimes, electrolyte, cathode and anode were observed and analyzed. As result, low arsenic anodes were more likely to be passivated due to their microstructure defects and irregular microstructure. Increasing electrolyte temperature and addition of glycerol were propitious to reduce low arsenic anodes’ passivation. The floating slimes occured when the concentration of As(III) in electrolyte decreased to 1 g/L, and they would be precipitated by polyacrylamide. All measures greatly improved the cathode quality at current density of 300 A/m ².

Aluminium matrix composites offer a combination of properties such as lower weight, higher strength, higher wear resistance and many more. The stir casting process is easy to use, involves low cost and is suitable for mass production compared to other manufacturing processes. An in-depth look at recently manufactured aluminium matrix composites and their impact on particle distribution, porosity, wettability, microstructure and mechanical properties of Al matrix composites have all been studied in relation to stirring parameters. Several significant concerns have been raised about the sample’s poor wettability, porosity and particle distribution. Mechanical, thermal, and tribological properties are frequently studied in conjunction with variations in reinforcement proportion but few studies on the effect of stirrer blade design and parameters such as stirrer shape, dimensions and position have been reported. To study the effect of stirrer blade design on particle distribution, computational fluid dynamics is used by rese­archers. Reported multiphysics models were k-ε model and the k-ω model for simulation. It is necessary to analyse these models to determine which one best solves the real-time problem. Stirrer design selection and analysis of its effect on particle distribution using simulation, while taking underlying physics into account, can be well-thought-out as a future area of research in the widely adopted stir casting field.

Through the powder metallurgy technique, alloys of the eutectic composition of the Zn-Al system were manufactured (22.3 wt.%Al), reinforced with Ag additions (0.5, 1, 2.5, 5 wt.%), with subsequent annealing heat treatment at three different temperatures; 100, 150 and 200°C for 1 hr. X-ray diffraction, optical microscopy and mechanical tests were performed on the resulting samples. The addition of Ag favors the formation of alpha and beta compounds with Al and Zn respectively, which improves the compressive strength of the alloy. However, with the presence of Ag the hardness is decreased. On the other hand, the application of an annealing heat treatment, shows no significant effect on the evaluated properties of the alloy. The microstructure of the alloys resulted in the presence of very small grains smaller than 1 mm and with rounded morphology.

The study was intended to determine the effect of the input condition of the 17-4PH steel on the microstructure, mechanical properties and stress state of welded joints. The steel adopted for testing was in the solution condition at 1040°C, the aged condition at 550°C/4h and the overaged condition at 760°C/2 h + 620°C/4 h. Samples of 17-4PH steel, after heat treatment processed with different parameters, were electron beam welded (EBW). The microscopic observation (LM, SEM/EDS) showed that the microstructure of the weld consisted of martensite with a δ-ferrite lattice. In the heat-affected zone (HAZ), transformed martensite was found with evidence of niobium carbides. The results of hardness testing revealed the different nature of the hardness profile with the condition the material before the EB welding process. The hardness profile of the HAZ of the welded samples in the as-solution (ES2) and overaged (ES12) condition was varied (from about 340 HV to 450 HV). However, in the aged condition specimen of 17-4PH steel (ES22) showed a similar hardness level, at around 370 HV. The solution condition (ES2) had the highest strength properties R_m 1180.6 MPa with the lowest elongation A 7.6% of all samples tested. The aged welded specimen (ES22) retained high strength R_m 1103.4 MPa with a better relative elongation A 10.1%, whereas the overaged welded specimen (ES12) saw a reduction of strength R_m 950.4 MPa with an improvement in plastic properties A 18.8%. Obtained results showed a significant effect of the input steel condition on the obtained EB welded joints.

Bioactive glass (BG) can be utilized as a replacement and regeneration material for orthopaedic and orthodontic. However, a load-bearing structure requires good mechanical properties to withstand high stress, in addition to good bioactivity properties. In this research, BG and cordierite (BG-cord) composite was fabricated to improve BG’s mechanical properties. The mechanical strength of the BG-cord was investigated. Both BG and cordierite were synthesized separately using the glass melting method. The synthesized BG and cordierite powders were used to fabricate BG-cord using a composition variation from 10 to 50 wt.%. The composite with 30 wt.% cordierite demonstrated the highest diametral tensile strength (DTS), 14.01 MPa.

This study analyses the three-point bending behavior of Nylon 12 (PA12) specimens produced using two additive manufacturing technologies (i.e., fused filament fabrication and selective laser sintering). A Nylon 12 commercially available filament (from Fiberlab S.A.) was selected to employ the fused filament fabrication method (FFF) with a Prusa 3D desktop printer, whereas Nylon 12 sintering powder (from Formlabs Inc.) was chosen for selective laser sintering (SLS) using a benchtop industrial SLS platform, Formlabs Fuse 1, with a powder refresh ratio of 30%. The bending strength and flexural elasticity moduli were determined by following ISO 178:2019 standard specifications to assess the effect of two different technologies on the mechanical behavior of three-point bending specimens produced in three distinct build orientations (i.e., 0°, 45°, and 90°) relative to the printing platform. One-way ANOVA analysis, Tukey’s HSD, and Games-Howell tests are considered to assess the statistical variability of experimental data and compare the mean values of bending strength and flexural moduli. The testing results for the three orientations under question show notable differences and interesting similarities either in terms of strength or elasticity response for a significance p-level of 0.05.

Aluminium metal matrix composites (AMMCs) playing a prominent part in the aerospace and automotive sectors owing to their superior mechanical and tribological properties. Hence, the aim of this work is to investigate the effect of titanium dioxide (10 wt.% TiO2) particles addition on hardness and tribological behaviour of Al-0.6Fe-0.5Si alloy (AA8011) composite manufactured by stir casting method. The surface morphology of developed composite clearly shows the inclusion of TiO2 particles evenly distributed within the matrix alloy. Hardness of the composite was measured using Vickers micro hardness tester and the maximum hardness was obtained at 95.6 Hv. A pin-on-disc tribometer was used to carried the wear test under dry sliding conditions. The influence of wear control parameters such as applied load (L), sliding speed (S) and sliding distance (D) were taken as the input parameters and the output responses considered as the specific wear rate (SWR) and co-efficient of friction (COF). The experimental results were analyzed using Technique for Order Preference by Similarity to Ideal Preferred Solution (TOPSIS). Based on the TOPSIS approach, the less SWR and COF achieved at the optimal parametric combination were found to be L = 30 N, S = 1 m/s and D = 2000 m. ANOVA results revealed that applied load (76.01%) has the primary significant factor on SWR and COF, followed by sliding speed (20.71%) and sliding distance (3.12%) respectively. Worn surface morphology was studied using SEM image of confirmation experiment specimen to understand the wear mechanism.

In zinc electrowinning, small amounts of manganese ions additives are needed in the electrolyte to reduce the corrosion of anodes and minimize the contamination of cathodic zinc by dissolved lead. However, excess manganese oxide could cover the dimensionally stable anodes (DSA) surface and decrease their service life. Additives of phosphoric acid are put in the electrolyte to complex the manganic Mn3+ ion and hence reduce its disproportionation to MnO2. In the investigation, phosphoric acid was added to sulfuric acid or zinc electrolytes, and conventional and recent electrochemical measurements were carried out to examine electrochemical behaviour of DSA (Ti/IrO2-Ta2O5) anode during zinc electrolysis at 48 mA/cm2 and 39°C. It was observed that the anodic potentials of DSA anodes were lower by 27 mV after 5 h polarization in the zinc electrolyte containing 35 g/L phosphoric acid at 39°C. Electrochemical impedance measurements show that the addition of 35 ml/L H3PO4 to the zinc electrolyte can increase impedance resistances of the DSA mesh anodes. Cyclic voltammogram studies (CV) at a scan rate of 5 mV/s without agitation show that the oxidation peak in the solution with 35 ml/L phosphoric acid addition is highest, followed by that with 17 ml/L phosphoric acid addition and that without addition of phosphoric acid.

Quaternary ammonium salt (QAS) Hyamine 1622 and benzotriazole (BTAH) were used to form a protective layer on copper surface to resist the corrosion by immersing the copper into the inhibitors-containing solutions. The inhibitor’s anticorrosion properties are studied in neutral 3.5 wt.% NaCl medium by anodic polarization, Tafel polarization, electrochemical impedance spectroscopy (EIS) and OCP exposure. The surface characterization is analyzed by Contact angle(CA) measurement, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy(SEM). The electrochemical tests show that they can act as single inhibitor to form a passive layer to resist Cu corrosion, and the anticorrosion properties of Cu can be improved by using binary Hyamine 1622/BTAH inhibitors. XPS results indicate that both BATH and Hyamine 1622 molecule can be chemisorbed onto the copper surface and make complex films with Cu species. CA measurement revealed the enhancement of hydrophobicity by combining QSA with BTAH. OCP exposure in neutral medium for 72 h evidently reveals that the passive layer formed by binary inhibitors decreases the pit corrosion. Better hydrophobic nature and more compact passive layer give rise to excellent inhibition properties of binary inhibitors.

This study utilizes Ti-8Nb-4Co alloys added to different proportions of Mo2C powders (1, 3, and 5 mass%) by the vacuum sintering process of powder metallurgy and simultaneously vacuum sinters the alloys at 1240, 1270, 1300, and 1330°C for 1 h, respectively. The experimental results indicate that when 3 mass% Mo2C powders were added to the Ti-8Nb-4Co alloys, the specimens possessed the optimal mechanical properties after sintering at 1300°C for 1 h. The relative density was 98.02%, and the hardness and TRS were enhanced to 69.6 HRA and 1816.7 MPa, respectively. In addition, the microstructure of vacuum sintered Ti-8Nb-4Co-3Mo2C alloys has both α and β-phase structures, as well as TiC precipitates. EBSD results confirm that the Mo ₂C in situ produced TiC during the sintering process and was uniformly dispersed in the grain boundary. Moreover, the reduced molybdenum atom acted as a β-phase stabilizing element and solid-solution in the titanium matrix.

Cube Satellites are miniaturized satellites used for space research with a mass of not more than 1.33 kg per unit. They are widely used in space applications because of its low cost of manufacturing and flexibility of applications. Since, they use commercial off-the-shelf components, thermal consideration of internal components of 1-unit cube satellites becomes a necessity. In this paper, transient thermal analysis of a 1-unit cube satellite is conducted to analyze its behavior during the first 29 seconds of orbit insertion from the launch vehicle. Transient thermal analysis yielded a temperature range that exceeded the optimum limit. As a result, to reduce heat dissipation, two main types of thermal management systems for satellites: active control and passive control systems are included. To maintain critical components at their operating temperature, a passive thermal control is implemented. Thermal strap and multi-layer insulation are used to analyze internal components of 1-unit cube satellite. Using graphite fiber thermal strap and aerogel multi-layer insulation for internal components, the 1-unit modular cube satellite is found to be more suitable under low earth orbit conditions.

The 0.05 mm-thick 304 stainless steel foil was annealed within the temperature range from 950℃-1100℃ for 10 minutes to obtain different microstructures. And micro-deep drawing experiments of stainless steel foils with different tissue structures were conducted to obtain relevant material forming properties influenced by dimensional effects. On this basis, the influence of the microstructure characteristics on the forming performance of 304 stainless steel foil and the quality of the cup formed by using micro-drawing was studied, and its mechanism was discussed. It can be seen from the results that the stainless steel foil annealed at 950℃ exhibits poor forming performance, and the wrinkle phenomenon of the deep-drawn cup is obvious. At the annealing temperature of 1050℃, the quality of the deep drawing cup is significantly improved. When the annealing temperature reaches 1100℃, with the increase of the annealing temperature, the crystal grains size increase sharply, and the coarse-grain effect causes the uneven plastic deformation effect to be obvious. Besides, the drawing quality is obviously deteriorated. The observation of the microstructure of the deep drawing cup shows that the forming effect of the drawing cup is poor due to the rolling defects and the coarse grain effect. The 304 stainless steel drawing cup annealed at 1050℃ enjoys the best forming effect.

The most commonly quenching process for carburizing gears is the oil-quenching (OQ) and salt-quenching (SQ), and finite analysis and comparison of OQ and SQ on the carburizing gear ring were performed. Wherein, the accurate simulation of gear carburization was obtained by the alloying element coefficient for diffusion coefficient and experiment validation. The heat transfer coefficients measured by the inverse heat transfer method was used to the temperature simulation, and the gear distortion mechanism was analyzed by the simulated results. By the comparison of OQ, SQ had higher cooling capacity in the high temperature region and slow cooling rate in the temperature range where martensite transformation occurs. The martensite transformation was more sufficient, and the compressive stress of the tooth was greater in the SQ. The tooth showed a drum-shaped and slight saddle-shaped distortion in the OQ and SQ, respectively. The simulated distortion results have good consistency with the measured results, and the SQ distortion was more uniform and stable based on the measured results.

In this investigation, the surface characteristics of Nickel based superalloy Inconel-625 were evaluated by the electrical discharge machining with used cooking oil-based biodiesel as a dielectric. Nickel-based superalloys find wide applicability in numerous industries due to their specific properties. The Cu electrodes of various densities prepared by atomic diffusion additive manufacturing process were used for machining. A comparison of the performance was made based on average surface roughness. The Design-expert software was used for experimental design and parametric analysis. The outcome demonstrated that bio-dielectric fluid produced improved surface characteristics. The surface roughness was observed to reduce. The surface micrograph obtained from scanning electron microscopy also confirms a better surface finish of bio-dielectric fluid over EDM oil. The surface roughness was shown to be most significantly influenced by the discharge current, with the other parameters having little or no effect. The results showed that for bio-dielectric, the lowest Ra was 0.643 µm, and for EDM oil, the highest value of 0.844 µm. The slightest difference in roughness value for two dielectric fluids was 0.013 µm, and the highest difference was 0.115 µm.

The application of titanium alloys is limited due to their low surface hardness and wear resistance, especially for parts operating under friction and contact loads. One of the most widely used technologies for the thermochemical treatment of titanium alloys is gas nitriding. A new method in this direction is surface plasma gas nitriding using indirect arc plasmatrons operating in a chamber with a controlled nitrogen atmosphere. In the present work, the changes in the phase transformations, microstructure, and surface hardness of titanium alloy Ti-8Al-1Mo-1V after plasma gas nitriding at the power of 18 kW, and 25 kW for a time between 5 and 30 minutes are studied. The plasma gas nitriding with the indirect plasmatron of the titanium alloy produced continuous surface layers. Analysis of the surface showed the presence of TiN and TiO2. The thickness of the plasma gas nitrided layers ranges between 100 μm and 350 μm, depending on the technological parameters.

The aim of the study was to determine the influence of the amount of a commonly used binder in foundry work, furfuryl resin – on the course of the thermal regeneration of used moulding sand. The thermal regeneration procedure was carried out at a temperature of 525°C, the required temperature determined according to a specific procedure, and a lower and less effective temperature of 400°C. On the basis of the ignition losses, the influence of the regeneration temperature on the effects of the procedures carried out was compared. It was found that 400°C was too low to effectively clean the binder matrix, but that the more resin in the spent sand, the more intense the cleaning effect. When the required regeneration temperature for furfuryl resin of 523°C was used, higher binder degradation kinetics were observed due to the additional energy supplied to the process from the combustion of a large amount of organic material in the moulding sand.

In this work, a new supplementary formula was introduced to modify the Kerner model. This supplementary formula enable the Kerner model to predict the thermal expansion coefficient of multi-phase reinforced composites by normalization of the thermal expansion coefficient, bulk modulus, and shear modulus of the reinforcements. For comparison, the modified Kerner model as well as modified Schapery, the rule of mixtures, and Turner models were used to predict the thermal expansion coefficient of multi-phase reinforced composites 6092 Aluminum Alloy/silicon carbide/β-eucryptite. The results confirm the robustness of the modified Kerner model for predicting the thermal expansion coefficient of composites with multi-phase near-spherical inclusions. It may provide a fine selection to predict the thermal expansion coefficient of multi-phase reinforced metal matrix composites which cannot predict efficiently before.