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Copper-nickel alloys have been used in many applications in marine environments because of excellent corrosion and biofouling resistance. . This investigation is cover a review of many previous studies about the behavior of these alloys in marine environments with different environmental conditions including the effect of sulphur contamination, the effect of CO2, the effect of chlorine, the effect of flow velocity, the effect of temperature and the effect of adding some alloying elements to the alloy itself. There have been conflicting results in the past about the corrosion rate values and the chemical analysis of the corrosion films in different environmental conditions. More research is needed for studying the behavior of these alloys in marine environments to provide good assessment of the corrosion resisting characteristics.

In this paper, the effect of sodium hexametaphosphate on the hematite was studied and the mechanism was analyzed. The results indicated that under the condition of the optimal grinding medium, compared with the result without sodium hexametaphosphate added, with citric acid added at the mass of 0.30% of the hematite, the content of-0.074mm of grinding production was increased by 6.38%; physical adsorption and chemical adsorption which were on the surface of hematite produced by sodium hexametaphosphate can reduce viscosity of grinding pulp, change surface potential of the hematite, and reduce the hardness on the surface of the hematite. Therefore citric acid can improve the grinding efficiency of the hematite.

In this paper, the effect of citric acid on the hematite was studied and the mechanism was analyzed. The results indicated that under the condition of the optimal grinding medium, compared with the result without citric acid added, with citric acid added at the mass of 0.10% of the hematite, the content of-0.074mm of grinding production was increased by 7.11%; physical adsorption and chemical adsorption which were on the surface of hematite produced by citric acid can reduce viscosity of grinding pulp, change surface potential of the hematite, and reduce the hardness on the surface of the hematite. Therefore citric acid can improve the grinding efficiency of the hematite.

Based on electrical and chemical analysis in oils of some fault transformers in Shenzhen, it indicates that the corrosive sulfur contained in insulating oils may cause faults. Corrosive sulfur would react to copper wire and engender Cu2S during the operation of transformer. Because of the electric characteristic of Cu2S, this substance will penetrate and pollute insulating paper of the wire, and then weaken the insulation intensity. At last it would wear out coil insulation. Experiments indicate that adding passivator to insulating oil is an effective method to solve the problem. Passivator can form a protection layer on the surface of copper, which can avoid copper corrupting and can stop copper deposition in the presence of potentially corrosive sulfur compounds as well.

An experimental research on comprehensive recovery of associated apatite from certain iron tailings in China was carried out. The phosphorus flotation is realized at low temperature through the application of the new, more efficient AW series collector. The test results showed that the concentrate whose P2O5 grade was 33.50%,recovery was 92.18% was obtained for the tailings whose P2O5 grade was 3.05% by one roughing under the pulp temperature of 15°C, thus realizing an effective recovery of apatite from the tailings.

In this study, the main aims were to iron-increasing and silicon-reduction of the iron concentrate by using centrifuge separating technology. Experimental studies were carried out on high-silica ferromagnetic iron concentrate in Dahongshan samples, which contain 50% of iron and 15% silica. Through the experiment, it chooses SLon1600 to iron-increasing and silicon-reduction of the iron concentrate. The optimum condition is pulp density of 20%~25%, feed speed of 1.99t/h, rinse water of 6.4t/h and flushing water of 10.22t/h. The iron concentrate which the grade of Fe is 62.36% and the recovery of 80.47% is obtained and the grade of silica reduce from 14.48% to 5.4%. High-quality iron concentrate is obtained, which has a better effect.

The 12CrMoV alloy steel is the most commonly used high pressure vessel and heat pipe using the material. This article on external forcing 12CrMoV alloy steel of high-temperature oxide layer for microscopic analysis of oxide layers of micro-cracks and exfoliation, oxidation layer portion of the oxide layer break, the oxide layer fold, multilayer structure oxide, oxidation and give the structure of the matrix and the proliferation of microstructure of the oxide layer. To compare 12CrMoV alloy steel for high temperature oxidation layer in a load-time and there is no loading time variation of topography.

Currently, Aluminium (Al) 6061 material is used in various industrial application and Automobile sector. Al 6061 gives good formability and excellent mechanical properties. This paper is mainly focused on the behaviour of the heat-treated aluminium alloy-6061 under the various test such as hardness test, impact test and other industrial applications. Based on the outcomes of Heat treatment, the quality of the Aluminium alloy-6061 is also compared with that of Aluminium alloy-5083, 6063. Hence, this paper helps in future research, which is based on the behaviour of the Heat-treated aluminium alloy under Hardness test.

Titanium sintered alloys have a special use in the technique because they have multiple advantages. Titanium and its alloys are characterized by remarkable physic-chemical, mechanical and technological properties. However, there are several such properties that have a lower value, such as friction behavior. Titanium and its alloys are recognized as having low wear resistance. Titanium alloyed with certain elements, such as tin or graphite, can lead to alloys with improved wear properties, with the specification that graphite does not exceed 1%. The technology of manufacturing titanium-based alloys is specific to powder metallurgy, but it also has some originality by choosing special sintering cycles. The paper aims to present a tribological characterization of the sintered TiAl alloy; the method uses the disc of the alloy that has been researched in contact with an alumina ball. The paper presents a detailed analysis of the wear tests carried out for four types of specimens obtained by different methods.

Glass, being considered as hard and brittle material is very difficult to machine into desired shapes. The readily available conventional machining process does not provide good surface finish thus requires additional machining process. This paper reviews the different existing non conventional machining process accessible till today for the machining of glass materials. This paper also discusses the advantages and disadvantages of the existing non conventional machining processes. The various hybrid non conventional machining processes are also studied with focus on machining output characteristics like MRR, surface finish, tool wear rate. This paper summarizes the selection of hybrid non conventional machining processes for the various type of glass.

The appearance of high power LED has put forward higher requirements for thermal management. The micro heat pipe (MHP) has high heat transfer ability and plays an important role in high power LED and other high heat flux device cooling. In this paper, we designed and fabricated a micro heat pipe with fluoroalkyl silane (FAS) surface modified glass cover. The contact angle of the working area of glass cover reached 95.49° and made working fluid drops fall back to micro groove of silicon substrate more quickly. Thus the new glass cover can speed up the circulation of working fluid and enhance the heat transfer. The experimental results also proved that hydrophobic glass cover has a better heat transfer capability. Besides, this novel MHP reached the stable working status faster. When the input heat power was 10 W, the balance temperature of MHP with hydrophobic glass cover was 22 oC lower than traditional MHP, while the balance time is 58 seconds less. The work presented in this paper provides a new direction for optimize the MHP, not only the wick structure in substrate, but also the wettability of cover plate.

This paper deals with the effective application of friction stir welding similar to butt joining technique.AL6063 T-6 alloys prepared in 125x 100 x 7mm thickness plate and FSW tool setup were H13 of diameter 25mm rotary tool with straight cylindrical pin profile. The maximum strength was considered for selection of combined process parameter. The process parameters were optimized using Taguchi method. The Rotational speed, welding speed, and axial speed are the main process parameter which taken into our consideration. The optimum process parameters are determined with reference to tensile strength of the joint. From the experiments, it was found the effects of welding parameter are the axial force is highest substantial parameter to determining the tensile strength of the joint. The paper which revealed the optimal values of process parameter are to acquire a maximum tensile strength of friction stir welded AL6063-T6 plates is 101.6Mpa with the combination level of rotational speed, welding speed and axial force are found to be 1100 RPM, 60 mm/min and 12.5 KN. validation test was carried out and results were nearer to the optimized results confirmed by the optimum results.

The paper deals with a solution to increase the machining rate at electrical discharge machining aided by ultrasonics (EDM+US), i.e. the overlapping the voltage pulses provided by EDM generator on the cumulative microjets stage (CMS), which occurs at every final of an ultrasonic period by collective implosion of the gas bubbles from the working gap. This overlapping moves the limit of the removed material by a discharge from the boiling isothermal (at classic EDM) to melting isothermal (at EDM+US) as it is emphasized by the results of finite element analysis. The preliminary experimental data analyzed in the paper are obtained in case of random overlapping at ultrasonic frequency of 20 kHz. They demonstrate an increase of machining rate with more than 300% at EDM+US in comparison with classic EDM in the same working conditions.

New tools for flat grinding are the subject of the paper. Electroplated diamond tools with different grains - D64 and D107 - were used in a modified single-disc lapping machine configuration. The results from flat grinding, such as the material removal rate (MMR), surface roughness and plane-parallelism are presented in the paper. Apart from ceramic samples, the additional experiments were carried out on cemented carbide workpieces (H10S) with the use of a diamond electroplated tool (D64). SEM microscopic images of unworn and worn active tool surface are presented with abrasive grains worn by attrition and cavities in the nickel bond after the grains pull out.

This paper reports the results of measurements during hardening and drying of specimens made of alkali activated slag mortars. The aim of this paper is introduce the effect of curing method and time on the microstructure of alkali activated slag mortars. An understanding of microstructure−performance relationships is the key to true understanding of material behaviour. The results obtained in the laboratory are useful to understand the various stages of micro-cracking activity during the hardening process in quasi-brittle materials such as alkali activated slag mortars and extend them for field applications.

Friction Stir Welding (FSW) is the latest innovative and most complex process which is widely applied to the welding of lightweight alloys, such as aluminum and magnesium alloys, and most recently, titanium alloys, copper alloys, steels and super-alloys. Friction stir welding is a highly complex process comprising several highly coupled physical phenomena. The experiments are often time consuming and costly. To overcome these problems, numerical analysis has frequently been used in the last ten years. In this paper is presented a brief review of scientific papers in recent years on numerical simulation of Friction Stir Welding of aluminum alloys. The main elements analyzed by FSW simulation, and briefly in this paper are: temperature and residual stress distribution; work tool geometry (size and shape of the pin); distribution of equivalent plastic deformation; main areas resulted after welding; distribution of microstructure (grain size); parameters and optimization of the FSW process.

The most common and serious defect in casting is porosity, which is the result of two phenomena namely, insufficient feeding and hydrogen precipitation during solidification. Formation of porosity defect in aluminum alloy is a complex process. Researchers have modeled the pore formation using analytical solution, criteria function and heat transfer simulations. Each model has its own advantages and disadvantages. This paper review the various papers which deals the models based on orthogonal array, Niyama criteria and GA/ANN.

In manufacturing industry there are many applications for the permanent joint of components of different shapes, but they are also very different in terms of chemical composition and structure [1, 2]. This paper is trying to find technological solutions of assembling by welding of two steels with totally different chemical composition, i.e. carbon steel S235JR + AR and austenitic stainless 316L. The process used for making the heterogeneous joint was Metal Inert Gas (MIG) with flux cored wire, numerically coded 137. The paper presents the effects of welding technology, through heat input, such as hardness. Variations of hardness values determined in the joint areas are presented, as well as the chemical composition of the welded joint obtained using the flux cored wire T 23 12 LPM 1/C1, according to EN ISO 17633 - A.

This paper fits into an experimental researches complex, regarding the surface roughness dependency on the cutting parameters of 7136 aluminum alloy machining. The purpose of this paper is to identify by experiments the influence of feed per tooth variation on surface roughness. A range of feed per tooth was used while the cutting speed and the cutting depth were constrained per minimum and maximum requirements defined for the given cutting tool. The experiments were conducted on Al7136 because it is a new material and I have identified the need for its use in the aircraft industry.

Aluminium matrix composites have received the attention of numerous researchers, because of its attractive properties like high strength, good thermal conductivity and more strength to weight ratio. Application of the conventional welding processes for aluminium matrix composites, facilitates the formation of undesirable phase at the welded region, which limits the wide spread application. The objective of this paper is to review the literatures belonging to the friction stir welding of the composites and explore the challenges associated to maximize joint efficiency. The major contribution of this paper is to study the issue of welding of ex-situ and in-situ composites, various process parameters, properties of joint and post weld heat treatment process to improve the joint efficiency. This literature review provides some research gaps in the friction stir welding of composites.

The paper is devoted to investigating the position of the anode spot on the cut edge during high-precision plasma processing and studying the trajectory of the melting products flowing from the cut edge. The material of samples is structural steel of St3 (GOST 14637-89) having the thickness of 3, 4, 5, 6 and 8 mm. The formation of the cut edge was carried out according to the HiFocus technological scheme of cutting by using the equipment manufactured by the Kjellberg firm (Germany). It was found that among technological parameters such as current, cutting speed, pressure and flow rate of cutting and swirl gases considered in the paper the greatest influence on the position of the anode spot on the cut edge is made by the cutting speed. For the investigated technological scheme of cutting the ratio between the anode spot and the thickness of the cut material lies in the range from 0.42 to 0.47. The optimization of the processing speed is based on studying the trajectory of the melting products outflow from the cut edge.

Solder joints are exposed to drop impact, vibration loading, bending, and twisting of PCBs. Study on this matter will lead to prediction of fracture load, prevalent fracture mode, exact joint interconnect size and life of joints under brittle and fatigue failure. This paper presents a finite element modeling of intermetallic compounds solder joints failure based on displacement extrapolation method. Based on conceptual FE model of intermetallic IMC solder joints, this paper present the full model of IMC model for intermetallic Mode I and Mode II fracture prediction.

Conventional recycling methods of industrial waste such as ferrous and non-ferrous chips and broken graphite are ineffective. In this paper we investigate exothermic remelting of industrial waste. Parameters of the most effective recycling conditions which result in a maximal yield of reduced metal and high efficiency of steel casting have been determined. The influence of the aluminothermic mixture density, a fraction and a granulometric composition of the mixture initial components on the metallic yield is shown in the paper. The possibilities of reducing the material content in the thermite mixture are also discussed. The most productive process of steel casting with the use of industrial waste which makes it possible to reduce the overall dimensions of casting molds and the bulk of molding materials is proposed.

Nitriding is the most common surface engineering technique that is being used in Titanium alloys for improving their surface properties, viz hardness, wear resistance, etc. Ti6Al4V (Grade 5) Titanium Alloy is a super alloy that exhibits excellent mechanical strength; it is highly resistance to creep at very high temperatures which maintains good surface stability. It is resistant to corrosion and oxidation. The main objective of this review paper is to study the recent research works carried on Nitriding of Ti6Al4V alloy by using, viz gas Nitriding and laser Nitriding. This process is used in the surface hardening of machine parts such as aircraft engine parts, crank pins, valve seats, gears, bush, aero engine cylinders, aero crank shafts. Gas Nitriding is a diffusional technique in which the nitrogen atoms are diffused into the surface of the metal to obtain hard surface. By Laser Nitriding is a diffusional technique by which the surface properties of the titanium alloy is enhanced. Laser nitriding process comprises of various stages, viz, transport of heat, melting effect, diffusion and convection effect. By Nitriding technique the surface hardness of super alloys like Titanium Alloy Ti6Al4V Grade 5 can be increased by increasing the hardness on the surface there by its scope of application is widened. In this paper a literature survey is carried out and the recent research works on surface engineering of Ti6Al4V alloy using gas and laser Nitriding technique is summarized.

The paper considers the influence of melting technology and out-of-furnace treatment on the nature and amount of nonmetallic impurities in rail steel. The dependence of the nature of nonmetallic impurities on oxygen concentration in steel is stated. The paper demonstrates the influence of oxygen concentration on rail metal quality.

This paper mainly introduces a novel route for copper recovery from waste printed circuit boards (WPCBs) via mechanochemistry. Copper in the crust is most commonly present as copper-iron-sulfide and copper-sulfide minerals (about 80%) and there exist many methods to extract copper from cooper ores in mineral engineering. It seems an alternative to transform the metallic components in obsolete materials to their corresponding compounds common in nature. By means of mechanochemistry, copper and sulfur were verified to form into copper sulfide in the model experiment, where, meanwhile, the optimal ball milling time was determined (20 minutes). In the real experiment, WPCB fragments and sulfur were mixed and ground for 20 minutes, no copper was detected by XRD analysis but copper sulfide was left. After leaching in sulfuric acid (3M) and hydrogen peroxide (30 wt%), the yield of copper reached nearly 95% and, also, resin was conserved for further utilization. This paper, for the first time, reports the green recovery route combining mechanical activation and sulfurization and may provide an alternative in other studies of metal recovery.

This paper presents an experimental investigation on cutting performance in turning of mild steel with application of minimal quantity lubrication (MQL) by using vegetable oils: canola oil, sunflower oil and palm oil. In order to study the effects of MQL on turning process, cutting temperature and flank wear were measured during the turning operations. Cutting temperature was measured using tool work thermocouple while flank wear was observed through SPG video microscope. The measured cutting temperatures and flank wear were also compared to that of dry cutting and water mist cutting. Results showed that among the vegetable oils, palm oil demonstrated highest cooling efficiency, at which reduction of 50 percent in cutting temperature compared to dry cutting. However, it was found out that MQL with canola oil yields the longest tool life. Reasons for such findings are also discussed in the paper.

In this paper is investigated the effect of building parts with different layer sizes using an additive manufacturing technique, from the statistical point of view. The paper is focused on the differences that appear at the stainless steel parts when the building layer is increased, this being done on the SLM 250 HL machine. This machine uses a fiber laser to melt fine powder on a layer-by-layer basis to create three-dimensional metallic parts from CAD files. The samples were constructed using two different layer thicknesses and then reprocess so that a micro hardness test could be employed. The micro hardness’s are compared using statistical methods. Overall, the obtained results indicate that the outcome influences the manufacturing strategy that it is chosen.

This paper aims to determine by experiment total stress and pressure of deformation depending on punch stroke and the level of deformation on severe plastic deformation of copper Cu_99.75 by multiaxial cold forging. The deformation process is discontinuous and includes deformation processes that define a cycle of severe plastic deformation. This paper aims to determine the stress and pressure corresponding to the first 12 cycles of severe plastic deformation.

In this paper different contact conditions between tool, chip and work material are analyzed. Experimental and theoretical studies of contact load distribution on the artificial flank wear land of the cutter in free orthogonal turning of a disk made from titanium alloy (Ti-6Al-2Mo-2Cr) are described. Investigations of cutting with various feed rate and cutting speed show that the greatest contact loads are observed immediately at the cutting edge. It is associated with the discontinuous character of titanium alloy chip and the elastic recovery of the transient (machined) surface at the moment when generated chip element is separated. The main influence of the variable chip thickness ratio of the discontinuous chip on the value of the greatest normal contact load near the cutting edge is shown that confirms the author’ hypothesis about a sag of the transient surface in the cutting edge region.Abbreviation and symbols: m/s – meter per second (cutting speed v); mm/r – millimeter per revolution (feed rate f); MPa – mega Pascal (specific contact load as stress σ or τ); hf– the width of the flank wear land of the cutting tool, flank wear land can be natural or artificial like in this paper [mm]; xh– distance from the cutting edge on the surface of the flank wear land [mm]; σh– normal specific contact load on the flank land [MPa]; τh– shear (tangential) specific contact load on the flank land [MPa]; HSS – high speed steel (material of cutting tool); Py r– radial component of cutting force on the rake face [N]; Pz– tangential component of cutting force [N]; γ – rake angle of the cutting tool [°]; α – clearance angle of the sharp cutting tool [°]; αh– clearance angle of the flank wear land [°]; b – width of a machined plate or disk [mm]; a – the thickness of the layer being removed (uncut chip thickness) [mm]; a1– chip thickness [mm]; Ka– chip thickness ratio (Ka= a1/a) as a degree of plastic deformation in chip formation zone; Ka2– variable chip thickness ratio, Ka2= a2/a1, where а2– distance from the rake face surface of the chip to the contact point of two neighbouring elements of the chip [mm]; Φ – shear angle [°]; hd– value, which determines the depth of deformation, for an ordinary task it is equal to the thickness of the machined part or the radius r of the machined disk [mm]; q – intensity of loading in the chip formation region [MPa].

The current paper first analyzed the degradation mechanisms of the worn disc cutter made of forged H13 chromium alloy for hard rock tunneling applications. The paper investigated subsequently the mechanical properties of H13 to have a better understanding of the degradation mechanisms. Hardness tests were carried out on different positions on a cutter. Tensile tests and fracture toughness were carried out to investigate temperature effects. The test results showed that the material has a high wear resistance and a good temperature resistance, but its quasi brittle behavior and the residual stress effect (due to the cutting process) is critical for the chipping damage of the disc cutter.

Non-destructive acoustic analysis methods, Impact-echo method as a traditional and the Acoustic Emission method as nontraditional method for civil engineering, were used for experiment. This paper reports the experiment during hardening and drying of specimens of alkali activated slag mortars. Alkali activated slag is a material having a great potential to be used in practice. The main drawback of this material is a high level of autogenous and especially drying shrinkage, which causes a deterioration of the mechanical properties. The aim of this paper is introduce the effect of method used and time curing on the microstructure of alkali activated slag mortars. An understanding of microstructure–performance relationships is the key to true understanding of material behaviours.

In the paper, a region model considering grain shape, orientation and boundary is built based on Hall-Petch Equation. The constitute relationships of materials in grain region and grain-boundary region are deduced by introducing the scale parameter. The proposed model and constitutive relationships are verified by the experimental data. Using the region model, the micro-upsetting processes are simulated. The researches in the paper can be used to guide the other micro-forming processes which are more complex.

This paper studies the different calcination temperature on the properties of titanium gypsum physical effects, and the mechanism of the effects are discussed in this paper. Research has shown that with the increase of calcination temperature, the mechanical properties of titanium gypsum present a trend of after rising first down. When the calcination temperature is 180 °C, titanium gypsum calcined product mainly for the half water gypsum phase, the mechanical strength of samples of titanium gypsum achieve maximum at this time, The mechanical properties of titanium gypsum samples: 2h flexural strength was 0.94MPa, 2h compressive strength was 1.87MPa, absolutely dry flexural strength was 1.54 MPa and absolutely dry compressive strength was 2.52 MPa.

Carbon dioxide CO2could corrode the oil well cement paste matrix under agreeable moisture and pressure condition in deep oil wells, which could decrease the compressive strength and damage the annular seal reliability of cement paste matrix. The problem of oil well cement paste matrix corrosion by CO2was researched in the paper for obtain the feasible corrosion prevention technical measures. The microstructure and compressive strength of corroded cement paste matrix were examined by scanning electron microscopeSEMand strength test instrument etc. under different corrosion conditions. The mechanism and effect law of corrosion on oil well cement paste matrix by CO2were analyzed. And the suitable method to protect CO2corrosion in deep oil wells was explored. The results show that the corrosion mechanism of cement paste matrix by CO2was that the wetting phase CO2could generate chemical reaction with original hydration products produced from cement hydration, which CaCO3were developed and the original composition and microstructure of cement paste matrix were destroyed. The compressive strength of corrosion cement paste matrix always was lower than that of un-corrosion cement paste matrix. The compressive strength of corrosion cement paste matrix decreased with increase of curing temperature and differential pressure. The corroded degree of cement paste matrix was intimately related with the compositions of cement slurry. Developing and design anti-corrosive cement slurry should base on effectively improving the compact degree and original strength of cement paste matrix. The compounding additive R designed in the paper could effectively improve the anti-corrosive ability of cement slurry.

The paper presents research made to achieve environmental powder precursors from a CuSnP alloy, used in the manufacturing process of brazing materials, such as coated rods. The innovation of the paper consists in the elemental participation of the components in the new alloys, procedure that takes place in the alloying process, through coat conditions of the addition materials and by simultaneous obtaining the new precursors that fulfill high friability and deoxidation conditions of the participants in the brazing process. Developing the copper alloy batches is conditioned by a good protection to oxidation and gas absorption from the melting oven atmosphere. In order to protect the melt from the above mentioned phenomena’s we developed a slagging flux, boron-cryolithe type, which has melting proprieties below those of the copper phosphorus alloy, approx. 700°C. The load calculation was made based on the technical characteristics of the industrial base materials that were used, taking into account the loss coefficient of 5%. The melting, casting and cooling of the samples, dimensioned so they will be friable, was accomplished through classic procedures. The grinding of the sample, including the moistening thermic treatments, was achieved by experimental research, followed by calculations, based on the criteria of maximum yield for grinding. Estimating the sample friability, in the preliminary phase of the experimental determinations, was needed in order to restrain the testing domain, through structural and hardness analyses. The chemical composition of the samples was spectral determined on the copper and copper phosphorus programs.

JG590 steel is one of high strength, low alloy and high toughness engineering machinery steels, and its tensile strength is not less than 590MPa. The fatigue failure is one of the main forms of the welding structure failure. This paper studies the influence of the ultrasonic treatment on welded joint fatigue performance. Through the experiments, the paper compares the fatigue performance on as-welded welding joint with the performance on ultrasonic impact treatment welding joint. The results show that the ultrasonic treatment reduces the stress concentration factor by improving the geometry of the toe of weld’ area. It transforms the welding residual tensile stress on the surface of the welded joint into compressive stress, and makes the surface of the toe of weld’ area hardening. The fatigue strength of welded joint is increased by 114%, and the fatigue life increased by 133~184 times.

This paper welds a layer of austenitic stainless steel (SS316L) on specimen of low carbon steel (C15) with a cylindrical surface using MIG Technology in the experiment. The sample was upsetting experiment, cracks and material forming observation respectively using embossing punch, no lubrication flat punch and lubrication flat punch under the condition of 750 °C, 900 °C and 1050 °C. The paper research on forming mechanism of the specimen under laboratory conditions based on the experimental results, the axial symmetry theory model and Numerical Simulation.

This paper introduces the classification, properties and application of porous ceramic materials, reviewed preparation of porous ceramics. Taking fly ash and red mud as the main raw material to generate porous ceramics, the paper study the influence of different proportions of raw materials, sintering temperature, porosity of porous ceramic sample rate, bending strength, and microstructure. The results show that, fly ash and red mud proportioning and sintering temperature are the main factors that influence the structure and properties of samples. The 4# sample is a kind of high porosity and high strength quality of porous ceramics.

The paper studies the cold-hardening phenomenon of material in high precision stamping. Level of material cold-hardening can be evaluated with thickness of cold-hardening stratum Δg (that may reach 0.2mm) and with its toughness (that may increase up to 1.8 times). For a correct conducing of high precision stamping process, is need to know, from designing stage, the way that different factors influence the piece material cold-hardening.The paper proposes the cold-hardening index IE that characterizes global and correct the cold-hardening level of stamped material. It was studied, for a large range of metallic materials (non-ferrous, carbon steels and allied steels), the way that tool-piece friction which varies from dry friction (μ=0.5) to limit friction (μ=0.05) influences value and evolution of cold-hardening index IE. The remark is that a reduced tool-piece friction goes to cold-hardening index IE increasing.

Hydrogen is a kind of clean energy, and application is limited because the efficiency of hydrogen production was not high before. This work in the paper was to study how to advance the hydrogen production efficiency by adding rare earths in the process of electrolysis of water. The result of tests proved that the efficiency of hydrogen production of water electrolysis electrode is dramatically improved when a few of REs are added in plating bath, and La cations are more effective than Ce cations when being added in the plating bath. Besides that, this article illustrated positive impact of RE on process of plating as well as effect of RE on composition of the plating and corrosion resistance of surface of the coating. Furthermore, argumentation extended to it that RE alone and compound of La and Ce have affected on efficiency of hydrogen production by water electrolysis process. Finally the paper showed that a new mechanism had been presented in a new angle being established in effect of RE on electron state of Ni plating.

This paper analyzed the corrosion environment of Missan oilfields and investigated the oilfield country tubular goods used in other similar oilfields. Summarized the effect of partial pressure ratio of H2S/CO2 and Cl-to the corrosion behavior of OCTG. This paper concluded the service condition, test results and anti-corrosion mechanism of carbon steel, low-chrome steel, modified martensitic stainless steel and nickel alloy. Finally arrived at conclusion that the nickel alloy can meet the requirement of Missan oilfields, some literature reported that the modified martensitic stainless steel can apply in H2S/CO2 environment. In the condition that be easy to replace the tubular, carbon steel and low-chrome steel tubular can meet the requirement with corrosion inhibitor.

In this paper, the solidification behaviors of hypoeutectic grey iron under different vacuum conditions in lost foam casting (LFC) were discussed by using thermal analysis method. In order to reveal unique solidification characteristics in LFC, green sand casting (GSC) is introduced as comprehensive study. To comprehensively investigate solidification process, several groups of continuous cooling curves were taken from the geometrical center of the different thickness section (from 5mm to 45mm) of the stepped test bar in practical pouring experiment for the above two processes. And the first derivative of these cooling curves and key temperature points were evaluated. In this paper, through more complete comparative analysis of cooling curves, vacuum environment in LFC would not only change the filling characteristics of melt, but also importantly effect on the further solidification of melts, thereby effect on solidification processes and structural feature of hypoeutectic grey iron.

This paper deals with the improving lay of finish and the superfinishing of the nozzles which is used in plasma cutting operation. This is basically alternative solution to present finish obtained by turning, drilling and reaming of the profiled bores and orifices. The advance micromachining process were developed, known as Abrasive Flow Machining (AFM) which is capable to altering the orifice (nozzle of plasma cutting machines) so that present process is to be improved without altering the geometry of the component. The effects of different process parameters such as number of cycles, concentration of abrasive, abrasive mesh size and media flow speed, surface finish are studied here. The design of the experiments 16(24) provides two levels for each variable. These levels are taken into consideration for finding out the effect of variation of parameters on the surface roughness of the copper orifice. The objective of paper is to learn how each parameter is considered for Abrasive Flow Machining such as: abrasive concentration in media, number of cycles, abrasive mesh size and media flow speed affects the surface roughness of copper orifice also to find out the mathematical relationship between surface roughness value and process parameters. Analysis of Variance (ANOVA) for the experimental data has been carried out and optimizations of abrasive flow machining process parameters were done. Also Analytic Hierarchy Process (AHP) done here for selecting hierarchy process parameter .Capabilities of the machine ultimately improved with the new technology developed.

The article proposes possible increase of durability of tool steel X210Cr12 as regards working conditions under consideration of abrasive wear. From such steel tools are made for pressing wooden briquettes and saw dust waste. In practical environment a condition is held that if a material should work in abrasive wear conditions, it should have high hardness and should contain carbides in the structure. The proposed paper deals with the heat and chemical-heat treatment (nitriding) of tool steel which is working in hard abrasive wear conditions. From the obtained results it is not easy to conclude a definitive conclusion or to set the boundaries between the factors that are responsible for wear resistance. It is shown that the chemical-heat treatment can in the last step of the heat treatment lead to an increase or even to a decrease in the abrasive wear resistance of the material. The aim of the paper is to set a proper heat treatment of materials used for pressing in abrasion wear conditions.

Exposure to welding fumes and its related hazards has always been a matter of serious concern. The mass and composition of fumes from welding depends on several factors. A detailed knowledge of these factors is necessary for understanding the mechanism of fume formation and developing suitable control strategies. This paper gives a literature overview on the various factors affecting welding fumes and strategies for controlling it. The paper focus on types of welding process like Manual Metal Arc Welding (MMAW) or Shielded Metal Arc Welding (SMAW), Gas Metal Arc Welding (GMAW), Flux Core Arc Welding (FCAW), Gas and Tungsten Arc Welding (GTAW). The research in the area of controlling fumes at the source has grown rapidly recently. Still, effective methods have hardly been explored. Improving arc stability by addition of materials with low ionization potential to the welding electrode lead to promising new research directions.

In this paper, a detailed comparison between dry, wet and gas-cooled turning has been presented based on experimental study. Machining of super duplex stainless steel is considered. Cutting tool considered in this paper is uncoated carbide tool. It was observed that gas cooled machining provides a better machining performance while compared with the dry and the wet machining. Gas cooled machining is particularly needed in case of high speed machining and hard turning. In this study we investigated the chip morphology for various condition of machining and concludes that gas cooled machining is suitable for machining at higher production rate..

The main purpose of this paper is to predict the tip's surface temperature of milling stainless steel using chamfered main cutting sharp worn tools. The cutting temperature model incorporating tool wear factor and using the variations of shear and friction plane areas occurring in tool worn situations are presented in this paper. The heat generate on elementary cutting tools are calculated by using the frictional cutting forces. Comparing the experimental forces measured by the dynamometer, that is good agreement. The carbide tip’s temperature calculates by loading the friction forces and tip’s parameters and the temperature distribution are solved by finite element analysis method.

Paper is focused on development of hydration heat in concrete in time. Possible ways of reduction of temperature during concrete hydration are mentioned. Paper presents study of possibilities of regulation temperature in concrete during hydration by selection of suitable input components. Blast furnace slag and micronized limestone were added to pure Portland cement; several variants of proportions were proposed.

In this paper, Si was added to the Al alloy to research its effect on the wettability between SiC and Al at 1000°C. The results showed that the contact angle decreased with the increase of Si content in the Al alloys and it droped from 570 to 370 with the Si content from 0 to 12wt% and reached equillibrium with the further addition of Si to 18wt%. The improvement mechanism of Si on the wettabitliy is also discussed in this paper.