bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanochemical Activation of Polymetallic Ore and Further Selective Floatation
Authors: Svietkina Olena , Bas Kostiantyn , Haddad Jamil , Ziborov Kyrylo , Olishevska Valentyna
Published: May 2020

It has been demonstrated that shock-vibrating activation of minerals is a prospective method to impact the ore; it may be used to intensify chemical and physical-chemical processes of mineral raw material processing and preparation. Differences in the composition and phase properties, obtained both in terms of continuous and periodic modes, are in the fact that in the first case loadings deal with interlayer space preserving layered nature of the mineral. When the mode is continuous, then the disturbances cover the octahedral layer though elementary constituent – tetrahedrons – are preserved. It has emerged that the most important advantage of high reacting capability of activated minerals is in the fact that leaching of some ores may be performed in chlorhydric acid at the expense of transformation of some silicate components into a specific state – loose packing of basic silicate chain. Consequently, shock-vibrating activation has become a basis to develop a method of leaching process intensification as well as a method to control phase formation.
The Laser Surface Treatment Effective on Structural Properties for Invar Alloy (Fe-Ni) Type Prepared by Powder Technology
Authors: Abdullah Omar Fadhilh , Hussein Orass Abdulhadi , Karash Emad Toma
Published: May 2020

This research aimed to prepare (Fe-Ni) alloy by powder technology method for its technological and commercial importance. Iron and Nickel powders were tacking then their powders mixed and blended together with percent (63% Fe-37% Ni), then the powders compacted isostatic cold pressure at (6 ton). Laser surface treatment was done for the samples with different energies (0, 200, 260, 300) mJ and pulse time (10 sec) At a distance (100 cm). The X-ray diffractions test indicated that all samples have Face Center Cubic (F.C.C), and the samples at 300 mJ has best properties which include increase of phases intensity and decrease of grain size according to Debye-Scherrer equation. The Atomic Force Microscope (AFM) also shows better properties with increase laser energy. Where increased soft-ness of surface, homogeneity surface and decrease in grain size with increase laser energy. The laser analysis resulted that melting all surface molecules which led to improvement in the structural properties.
Penetration Damaging Behavior of TB17 Titanium Alloy
Authors: Li Jing , Xin Yun Peng , Jiang Tao , Wang Xin Nan , Zhu Zhi Shou
Published: May 2020

The damage behavior of TB17 titanium alloy with ultra-high strength was studied by 12.7mm diameter armor piercing test. The characteristics and mechanism of damaging were analyzed by the observation of damage morphology of target board. The results indicated that the area was irregular at the opening stage, the internal wall were turtle-shell-like or poly-porous, a few cracks and no adiabatic shear band was observed. The zone was parabolic at the penetrating stage, the internal wall were granular or river pattern, adiabatic shear bands and fragments existed around the crater. A large number micro-pores and micro-cracks originating from the adiabatic shear bands expanded and formed macroscopic cracks. Finally, the target board fractured.
Cascades Damage in γ-Iron from Molecular Dynamics Simulations
Authors: Wu Shi , Cao Han , Wang Dong Jie , Jia Li Xia , Dou Yan Kun
Published: May 2020

The degradation of austenitic stainless steels under irradiation environment is a known problem for nuclear reactors, which starts from atoms displacement cascade. Here, molecular dynamics (MD) simulations have been used to investigate the formation of atomic displacement cascade in γ-iron for energies of the primary knock-on atom (PKA) up to 40 keV at 300 K. The number of Frenkel pairs increased sharply until a peak value was reached, which occurred at a time in the range of 0.1-2 ps. After that, a number of defects gradually decreased and became stabilized. Compared with α-iron, there was less defects in the stable stage, and more clustered defects were produced in γ-iron. Within the range of PKA energies, two regimes of power-law energy-dependence of the defect production were observed, which converge on 16.8 keV. The transition energy also marks the onset of the formation of large self-interstitial atom (SIA) clusters and vacancy clusters. Interstitial and vacancy clusters were in the form of Shockley, Frank dislocation loops and Stir-Rod dislocation loops.
Thermodynamic Calculation of the Liquidus Projections of the Al-Cu-Fe-Mg, Al-Cu-Mg-Si, and Al-Fe-Mg-Si Quaternary Systems on Al-Rich Corner
Authors: Zhao Jing Rui , Du Yong , Zhang Li Jun , Liu Shu Hong , Xia Jin Huan , Wang Jin Wei
Published: May 2020

The thermodynamic calculations of Al-Cu-Fe-Mg, Al-Cu-Mg-Si and Al–Fe–Mg–Si quaternary systems were carried out using CALPHAD method, based on the Al–Cu–Fe–Mg–Si thermodynamic database. The liquidus projection of Al–Cu–Fe–Mg, Al–Cu–Mg–Si and Al–Fe–Mg–Si quaternary systems at Al-rich corner were constructed, and the solidification structures of Al-12Cu-7Mg-1Fe, Al-14Cu-2Mg-4Si, Al-0.3Fe-6Mg-12Si (wt.%) alloys were analyzed by the Scheil solidification simulation. The calculated results agree well with the previous experimental data. The liquidus projections of three quaternary aluminum alloys at the Al-rich corner were accurately plotted, which could be helpful for the analysis of solidification process of multicomponent alloy systems, and provide an important theoretical basis for the material design of aluminum alloys.
Development of Interatomic Potentials for FCC Metals Based on Lattice Inversion Method
Authors: Duan Xian Bao , Zhang Zhi Peng , He Hui Zhen , Shan Bin
Published: May 2020

Interatomic potential plays an important role in molecular dynamics simulation, which determines both the efficiency and accuracy of the simulations. Lattice inversion is a method which can be used to develop interatomic potential from first principle results directly. In present work, a robust potential model based on lattice inversion is proposed. Then the potential model is applied to develop interatomic potentials for eight common FCC metals. The cohesive energy curves calculated using first principle calculations can be well reproduced, which verifies the reliability of the developed potential. Additional physical properties, including equilibrium lattice constant and cohesive energy, elastic constants, are predicted and found reasonable agreement with corresponding first principle results.
Bending Strength and Cutting Performance of WB-Coated-Diamond/Fe-Ni Composites
Authors: Zhang Xu Liang , Sun You Hong , Liao Yuan Chun , Jiang Wen , Li Jin Fan , Meng Qing Nan
Published: May 2020

Diamond particle with tungsten boride (WB) coating was synthesized by the molten salt method. Three different diamond/Fe-Ni composites made from pristine diamond, B4C coated diamond and WB coated diamond with Fe-Ni powders were prepared by powder metallurgy. The composition and microstructure of the tungsten boride coating were investigated. Both bending strength and cutting performance of the composites were investigated. Addition of the WB coating provided an increased bending strength (871.2 MPa) and relative density (93.54%), compared with the composites consist of uncoated diamond and Fe-Ni (746.8 MPa, 92.81%). Three different Fe-Ni-based impregnated diamond drill bits contained 20 vol.% pristine diamond, B4C coated diamond and WB coated diamond were manufactured by powder metallurgy, respectively. Drilling rate of bits was measured by XY-4 geological core drill on granite. The test results show that the drilling rate of bits with WB coated diamond (2.42 m/h) was 40% higher than that with pristine uncoated diamond (1.72 m/h).
Surface Control of K9 Glass/Diamondunder Cold Plasma Assisted Cutting
Authors: Meng Zheng , Liu Xin , Wu Ming Yu , Liu Jiyu , Chen Yang , Zhang Fan , Jin Zhu Ji
Published: May 2020

Surface properties of K9 glass/diamond materials were controlled under the optical brittle material by cold plasma assisted cutting machining. The influence of cold plasma jet on the tribological performance of K9 glass/diamond friction pair was investigated using the friction and wear test. The experimental results show that the plasma can be penetrated the surface of the brittle material. Cold plasma jet can regulate and control the K9 glass/diamond materials surface property and improve anti-friction effect.
Effect of Nickel Plating on MoS2 on Friction and Wear Properties of Cu-MoS2 Composites
Authors: Zhan Si Qi , Ran Xu , Zou Hao Hao
Published: May 2020

The copper-molybdenum disulfide composites were prepared by powder metallurgy under argon sintering atmosphere. The effects of nickel plating on the surface of the molybdenum disulfide on the friction and wear properties of the composites were studied. Friction and wear experiments with different frictional speeds and loads were carried out on the surface micromechanical testing system of UNMT-1 material. The microstructure and friction/wear morphology of the materials under different conditions were observed by laser scanning confocal microscopy(LSCM), scanning electron microscopy (SEM) and optical microscopy(OM). The results show that the sintering temperature increased from 720 °C to 920 °C, and the microhardness and wear properties were obviously improved. The reaction products of nickel-plated molybdenum disulfide and nickel-free samples were the same at different sintering temperatures, whereas the product content was the same. There was a significant difference between the micro-morphology and the surface of the molybdenum disulfide. The friction coefficient of the nickel-plated molybdenum on the surface of the molybdenum disulfide was relatively high, the wear was relatively serious, the wear surface was relatively rough, and the unnickel-plated sample exhibited good friction and wear properties.
Research Progress on Anti-Corrosive Properties of Graphene Modified Coatings
Authors: Zhu Li Juan , Feng Chun , Ge Hong Jiang , Cao Ya Qiong , Han Li Hong , Xie Bin
Published: May 2020

Graphene modified coatings have attracted extensive attention in recent years due to their excellent corrosion resistance and broad application prospects in the field of anti-corrosion. However, large-scale applications of graphene coatings were seldom reported, which is mainly attributed to the lack of fundamental research on the anti-corrosive mechanism and the long-term service performance evaluation of graphene modified coatings in actual working conditions. In the present work, the influence of the characteristics of corrosive medium, the content of graphene, the structure and morphology of graphene and the external environmental conditions on the anti-corrosive performance of graphene modified coatings were systematically reviewed. The deficiencies in the research of anti-corrosive performance of graphene modified coatings were summarized. The future work were prospected for the anti-corrosive performance and applications of graphene modified coatings in oil and gas exploration.
AlCoCuFeNi High-Entropy Alloy Coating Fabricated by Laser Cladding with Gas-Atomized Pre-Alloy Powders
Authors: Zhang Mi Na , Ouyang Wen Tai , Jiao Jun Ke , Zhang Wen Wu , Zhou Xiang Lin
Published: May 2020

AlCoCuFeNi high-entropy alloy coating was prepared by laser cladding with gas-atomized pre-alloy powders. The phase, microstructure and microhardness of HEA coating have been investigated. The results show that the AlCoCuFeNi coating was about ~ 800 μm in thickness, and the hard coating with strong metallurgical bonding to the substrate was obtained. The HEA coating is mainly composed of BCC dendrites phase and Cu-rich FCC phase within the interdendrite. The transition in structure from columnar to equiaxed grain can be observed in the coating due to the effect of different temperature gradient. The laser clad AlCoCuFeNi coating exhibited high microhardness of about 427.7 HV0.2, which was 2.5 times that of the 45# steel substrate.
Experimental Study on Flow-Induced Corrosion of Casing and Tubing Steel for Heavy Oil Thermal Recovery Wells
Authors: Chen Sen , Pan Jing Jun , Wang Mei Jie , Chen Deng Ya , Cheng Jia Rui
Published: May 2020

The tubing and casing in the thermal recovery well are subjected to corrosion damage of multiple thermal fluid flow during the service period, which may cause safety accidents such as thinning, perforation and even fracture of the pipe wall. In this paper, the corrosion behavior of J55 casing steel and N80 tubing steel in flowing media were studied by using high temperature and high pressure reactor. The test results reflected the effects of single gas concentration and temperature of O2 and CO2 on tubing and casing corrosion. Comparing and analyzing the corrosion law of tubing in distilled water and produced water, the results of column corrosion rate under hot steam injection and production conditions were obtained, which indicated the difference of corrosion and the influencing factors of tubing in two working conditions.
Fracture Failure Analysis of Φ50.8mm Coiled Tubing
Authors: Li Na , Zhu Li Xia , Cong Shen , Feng Yao Rong
Published: May 2020

The fractured coiled tubing of TS90 steel grade Φ50.8 mm ×3.96 mm in a certain oilfield was analyzed through macroscopic observation, magnetic powder inspection, physical and chemical properties testing, microstructure analysis and SEM analysis. The results showed that the coiled tubing fracture belonged to fatigue fracture and the fatigue crack originated from the area of cyclic friction on the outer surface of the tubing. The cyclic axial plastic stress of the tubing in service caused micro-cracks in the source area and finally led to fatigue fracture failure of the tubing.
Analysis of Corrosion Behavior on External Surface of 110S Tubing
Authors: Han Yan , Li Cheng Zheng , Zhang Hua Li , Li Yu Fei , Zhu Da Jiang
Published: May 2020

The failure analysis of 110S tubing during acidizing process was addressed. Results showed that serious pitting corrosion occurred on the outer wall of tubing, and there was no obvious pitting on the inner wall. The maximum pitting depth on the outer wall was 1019 μm. According to the results of simulation corrosion test, needle-shaped pitting appeared on the sample surface in the test without inhibitor, the maximum depth of pitting was 158 μm; and no pitting was found on the sample surface in the test within 1.5% TG501 inhibitor; the original pitting were deepened after spent acid test, and the sample with no pitting at the beginning also showed deep pitting corrosion after 96 hours spent acid test. It was indicated that the spent acid accelerated the development of pitting significantly. The external surface corrosion of the 110S tubing was caused by the chemical reaction between the high-concentration acidifying liquid and the outer wall of the tubing. There is a gap between the tubing and coupling threaded connection, which caused the acid solution entered into the thread position, and hence the severe corrosion of the thread and pin end of the tubing happened, the joint strength was continuously reduced with corrosion development till the tripping of the coupling, and then the lower string dropped. Some suggestions were proposed for avoiding or slowing down this kind of failure based on this study.
Surface Galling Mechanism Analysis of Rotary Shouldered Thread Connection
Authors: Li Fang Po
Published: May 2020

In this paper, surface galling failure process and mechanism of drill pipe’s rotary shouldered thread connection (RSTC) was studied by means of full-scale make-up and break-out (M&B) testing. The results showed that surface galling damage mainly appearred at the positions of leading flank, bearing flank and make-up shoulder of RSTC. The galling damage of three different positions was a process of mutual independence and mutual promotion, and they might appear simultaneously, and also appear at different stage. The surface galling failure was mainly due to metal’s plastic deformation and peeling off under the effect of compressive stress caused by friction and compression effect among the contacting metal surface. During M&B testing, deformed and peeling metal accumulated continually and resulted in "cold welding" at local position. In the subsequent M&B process, "cold welding" metal was torn open and peeled off from metal matrix, and metal surface galling was getting serious gradually. M&B testing results showed that torque load and thread compound had decisive influence on surface galling damage, while the influence of RSTC’s surface wear, rearranging, torque fluctuations and tensile load was not obvious.
Failure Analysis and Service Life Prediction of 80SH Casing Steel under Thermal Cycle Service Environment
Authors: Wei Wen Lan , Guo Long Long , Ju Lu Yan , Han Li Hong , Feng Yao Rong , Zhang Jian Bing , Zhang Qun Bing
Published: May 2020

The main exploitation process of heavy oil is cyclic steam huff and puff. Cyclic operation causes cumulative damage to thermal recovery casing and causes a large number of failures. Failure analysis shows that the main failure factor of thermal recovery casing is the low cycle fatigue process caused by thermal cycle, which results in the decrease of strength of casing material, thus causing casing fracture and failure. Based on the failure analysis results, the low cycle fatigue tests of 80SH thermal recovery casing steel under different temperature, strain, pre-strain and other conditions were carried out. The influencing factors, life prediction model and criterion of service safety of casing materials under thermal recovery service conditions were first proposed, which provides a strong theoretical basis for the service safety design theory of thermal recovery casing materials. The research shows that the strain limit and low cycle fatigue life are the two core issues of service life. Life predictions need to satisfy two criteria. The first is the strain criterion. The strain limit should be lower than the total strain during the long service life. And the second is the low cycle fatigue criterion, which satisfies the expectation of low cycle fatigue life under double conditions of strain amplitude and mean strain.
Effects of Compressive Stress on Carbonation-Induced Degradation of Oil Well Cement under CO2 Storage Environment
Authors: Gu Tao , Zheng You Cheng , Zheng You Zhi , Xia Hong Wei , Cheng Xiao Wei , Guo Xiao Yang
Published: May 2020

This paper presents an experimental study to investigate the effects of compressive stress during the CO2 attack on wellbore cement under carbon capture and storage (CCS) conditions. Oil well cement samples were designed to be exposed to humid supercritical CO2 gas and CO2-saturated brine and simultaneously subjected to external compressive stresses with load levels of 0, 25%, 50%, and 75% of the ultimate compressive strength. Morphology changes were determined using phenolphthalein dye testing and scanning electron microscopy. Mineral changes were detected by X-ray diffraction. Relative compressive strength and gas permeability of exposed cement were analyzed. It is shown that the 25% stress level has little effect on degradation of cement while the applied compression load up to 50% increased the compactness of cement and finally slowed down the degradation rate. In contrast, a much higher compressive stress level up to 75% facilitated the generation and propagation of micro-cracks. The stress induced micro-crack finally caused a surge in CO2-rich fluids and then significantly accelerated the degradation rate of oil well cement. Findings from this study expanded the understanding of the integrity of oil well cement for CCS wells.
Function Synergy of a New Type of Fluid Loss Additive Formula for Comprehensive Performance of Oil Well Cement
Authors: Wang Hao , Li Ming , Zheng You Zhi , Gu Tao
Published: May 2020

With 2-acrylamido-2-methylpropanesulfonic acid (AMPS) units on polymeric additive, additive showed high effectiveness used for oilwell cement. However, due to chemical absorption and chelation mechanism of AMPS units to Ca2+ hydrating cement particles, adding of AMPS type additives caused delay of cement hydration process. In this research, AMPS type fluid loss additive, named as FLA A additive, was studied for its hydration delay side effect to class G Portland cement. Furthermore, polyvinyl alcohol (PVA) polymer, modified by glyoxal and boric acid, called as PVAGB was used as a synergistic functional additive to AMPS type polymer fluid loss additive to research on hydration delay problem of AMPS type additive to cement and the improvement for the effectiveness of AMPS type fluid loss additive. When AMPS type additive showed functional drawbacks, with more disordered chemical absorption and chelation behaviors to Ca2+ hydrated cement particles rather than constituting a completed and superior fluid loss control system, and this kind of modified PVA polymer was utilized for making up its failure. New compound additive formula, PVAGB/FLA A fluid loss additive formula, was investigated, which showed superior and more stable fluid loss control ability, i.e. about 50 mL at 30°C and 108 mL at 80 °C with just 0.2 % BWOC (weight percentage by weight of cement) PVAGB and 0.5 %BWOC (weight percentage by weight of cement) FLA A addition. In addition, within 28-day curing period, cement samples showed a healthy compressive-strength development with no less than 28MPa after 7-day curing period rather than failure due to cement strength retrogression. With scanning electron microscope (SEM) analysis, PVAGB showed accelerating effect to cement hydration process, in which hexagonal plate Ca(OH)2 crystal and aggregated product of C-S-H gel were formed when compared with pure cement and cement with FLA A additive added.
Performance Evaluation of Polycarboxylic Acid Dispersant for Oil Well Cementing
Authors: Xia Xiu Jian , Yu Yong Jin , Jin Jian Zhou , Liu Shuo Qiong , Xu Ming , Zhang Zheng Rong
Published: May 2020

The conventional oil-well cement dispersant has the characteristics of poor dispersion at high temperature, poor compatibility with other additives, and environmental pollution during the production process. In this article, with ultra-early strong polyether monomer, acrylic acid, 2-acrylamine-2-methylpropyl sulfonic acid, sodium methacrylate as copolymer monomers, an environmentally friendly polycarboxylic acid dispersant, DRPC-1L, was prepared by the aqueous solution free-radical polymerization. The chemical composition and thermal stability of the synthetic copolymer were characterized by FTIR and TGA techniques. The evaluation results show that DRPC-1L has a wide temperature range (30~210 °C), good salt-resistance and dispersing effect. It can significantly improve the rheological performance of cement slurry, and it is well matched with oil-well cement additives such as fluid loss agent, retarder and so on. Moreover, it is beneficial to the mechanical strength development of set cement, especially the early compressive strength. It can also inhibit the abnormal gelation phenomenon of cement slurry, flash set, that occurs during high temperature thickening experiments, which plays an important role in enhancing the comprehensive performance of cement slurry. Consequently, the novel polycarboxylic acid dispersant has good application prospects in deep and ultra-deep wells cementing.
Synthesis and Application Performances of Solid Polycarboxylate Superplasticizers Using Different Initiators
Authors: Liu Xiao , Bai Xia Bing , Xu Qian , Xia Chun Lei , Lai Guang Hong , Guan Jia Nan
Published: May 2020

At present, the products of polycarboxylate superplasticizer (PCE) mainly present liquid state. Compared with liquid PCEs, solid PCEs have not only high storage stability, but also high water-reducing rate. Based on acrylic acid (AA) and isobutenyl polyethylene glycol (IPEG) as the main materials, a series of solid PCEs were synthesized under anhydrous condition by employing ammonium persulfate (APS), benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN) and azobisvaleronitrile (ABVN) as initiators, and the effects of different initiators on the application performances of these solid PCEs were also investigated. The molecular characteristics of the synthesized products were determined by Infrared Spectroscopy (IR) and molecular weight measurements to confirm the expected structure. The fluidities, dispersions and micro-observations of cement pastes containing solid PCEs were evaluated. For both liquid PCE and PCE-ABVN, the average particle size reduced from 2373nm to 1147nm. The results showed that the paste fluidity, concrete slump and retentions were significantly enhanced when using ABVN as initiator, with the initial slump up to 225mm. This initiator had high initiating efficiency, exhibiting broad application prospects.
Life Cycle Assessment of Green Production of Glass Substrate
Authors: Wang Yu Long , Gong Xian Zheng , Sun Bo Xue
Published: May 2020

In this study, the LCA assessment model of CML was employed to analyze the environmental burden caused by the production of glass substrates, and the evaluation of the environmental performance of five stages of preparation of ingredients, including glass melting, precision clarification, overflow molding and post process, was also conducted. The results show that the global warming potential is the dominant impact category in the comprehensive environmental burden with a normalized value of 4.64×10-14, followed by the acidification potential (2.57×10-14), photochemical oxidation potential (2.82×10-15). And the relative contribution of abiotic depletion potential and human toxicity to the comprehensive environmental burden is rather limited, with the normalized values of 8.31×10-17 and 1.21×10-16, respectively. The single score of environmental impact due to the whole production system is 2.37×10-13, wherein the environmental impact values of the processes of preparation of ingredients, glass melting, precision clarification, overflow molding, and post are 1.07×10-15, 9.10×10-14 (highest), 2.26×10-14, 7.36×10-14, and process 4.90×10-14, respectively. The preparation of the batch, the glass melting, the overflow molding and the post process mainly cause the environmental effects of global warming potential and acidification potential, the cumulative values of which are 1.13×10-13 and 9.01×10-14, respectively. The precision clarification stage mainly causes the environmental effect of acidification potential, the value of which is 2.02×10-14 and much higher than those of other environmental impact categories.
Preparation of CTS/MFA Composite and its Adsorption Property of Direct Dyes
Authors: Lv Ting , Li Bei Gang
Published: May 2020

A novel CTS/MFA composite was prepared by a solution reaction between chitosan (CTS) and fly ash modified by acid (MFA), and used for the adsorption of direct green BE (DG BE) and direct claret BE (DC BE) dyes. Some important conditions about preparation and adsorption of the composite were discussed in detail. The adsorption property of CTS/MFA was investigated. The results show that the obtained CTS/MFA (1:20 of CTS/FA mass ratio) has excellent adsorption properties for DG BE and DC BE dyes with adsorption capacities of 886 and 688mg/g , which are nearly 8 times higher than those of FA, respectively. The adsorption of CTS/MFA is strongly pH-dependent and the adsorption equilibrium can be reached in 90 minutes at 298K. The whole adsorption processes of two dyes fully conform to the pseudo-second-order rate model at different temperatures. The adsorption behavior can be described by Langmuir model well. It was found by the characterization of SEM/EDS and XRD that CTS was successfully loaded onto the MFA. The surface morphology of CTS/MFA changed significantly compared with that of FA, and the surface became more rough and uneven. As a cheap and easy-to-obtain composite material, CTS/MFA has a giant application potential for effective treatment of direct dye wastewater.
Comparative Life Cycle Assessment between Ordinary Gypsum Plasterboard and Functional Phase-Change Gypsum Plasterboard
Authors: Zhang Yan Jiao , Ma Li Ping , Ren Shi Wei , Huang Meng Chi , Wang Ying , Zhang Qi Long
Published: May 2020

With the emphasis of national policies on green manufacturing and the recognition of the people for green development, expanding the green assessment of products will be the general trend. In this study the life cycle assessment method was used to compile a list of resources, energy consumption and pollutant emissions during the life cycle of typical ordinary gypsum plasterboard and functional phase-change gypsum plasterboard, the key environmental impact indicators of both products during the life cycle calculated, the key stages affecting the environmental performance of products analyzed and identified, and the difference in environmental impacts between phase-change gypsum plasterboard and ordinary gypsum plasterboard compared and analyzed, for guiding the selection of green building materials and the development of ecological building materials. The results show that the global warming potential of phase-change gypsum plasterboard is 3.42 kgCO2 equivalent/m2, the non-renewable resource depletion potential is 2.25×10-5 kgSb equivalent/m2, the respiratory inorganic is 1.97×10-3 kgPM2.5 equivalent/m2, the eutrophication is 1.21×10-3 kgPO43- equivalent/m2, and the acidification is 9.47×10-3 kgSO2 equivalent/m2. Compared with ordinary gypsum plasterboard, the phase-change gypsum plasterboard shows the biggest increase by 874.03% in non-renewable resource depletion potential. The major environmental impact of ordinary gypsum plasterboard in the life cycle is mainly from energy use, and the transport process is the main stage of eutrophication. The use of phase-change materials in the phase-change gypsum plasterboard is the main stage causing environmental impact.
Technical Specification Development for Ceramic Tile Type III Environmental Declarations
Authors: Liu Yi , Zhang Yan Jiao , Wang Chen , Wen Gang , Ren Shi Wei
Published: May 2020

In order to address increasingly serious global environmental problems and intensified international trade barriers as well as the promotion of production processes by enterprises for the improvement of environmental impacts, Type III environmental declaration has emerged in response to the proper time and condition and gradually developed into an important mean to solve environmental problems. This study, based on the principles and requirements stated in ISO 14025, takes ceramic tile products as the example to discuss about the formulation of technical specifications for life cycle assessment of the ceramic tile, in order to provide methodological basis and technical support for the formulation of technical specifications for the life cycle assessment of other domestic products as well as for the assessment of Type III environmental declaration. AcknowledgementSources of project funds: 13th Five-year National Key R&D Plan “Study on Key Technologies for Certification of Green Products Used in Home Furnishing Field”(No. 2017YFF0211504)
Determination of Volatile Organic Compounds in Recycled Polyethylene Terephthalate Fibers by HS-GC-FID to Evaluate the Efficiency of Testing Conditions
Authors: Liu Shan Shan , Chen Ye , Wang Yu Hui , Gao Ling Ling , Ke Fu You , Wang Chao Sheng , Wang Hua Ping
Published: May 2020

A method to determine the volatile organic compounds (VOCs) in the recycled polyethylene terephthalate fiber was presented by using the headspace sampling-gas chromatography coupled to flame ionization detector (HS-GC-FID), in order to evaluate the level of VOC contamination. The extraction variables, such as the incubation temperature, the pre-incubation time and the size of the vial, were also studied. The effects on the determination of VOC were also compared using two type chromatographic columns. The optimal conditions were found using a headspace sampling for 20 min at 100 °C, where 120 mL vials and TM-1 column were prior to analysis of benzene compounds in PET(polyethylene terephthalate) fibers. The results can be used in analysis of VOC from recycled PET fibers.
Environmental Analysis on Co-Processing of Domestic Waste in Cement Kiln
Authors: Yang Xue , Lin Xin Ping , Wang Yan Jing , Liu Yu , Hao Li Wei , Sun Bo Xue
Published: May 2020

The annual output of domestic waste has exceeded 400 million tons in China since 2016, which causes an urgent demand on harmless disposal in the current rapid process of urbanization. Compared with traditional disposal means (e.g. incineration and landfill), co-processing with cement production seems to be a better chose to meet the requirements of domestic waste treatment (i.e. harmless, volume reduction, waste utilization). However, co-processing technology also has some negative impact (e.g. extra energy consumption for pretreatment of domestic waste), so the environmental feasibility of domestic waste co-processing in cement kiln should be verified. In this paper, the influences caused by domestic waste co-processing on the cement clinker products including resource/energy consumption, as well as the pollutant emissions were quantify based on the investigation of typical plants in China. Moreover, the environment impact between landfill treatment and co-processing scenario were compared using life cycle assessment (LCA) method. The result shows that the energy consumption and CO2 emission per ton cement clinker production increased by 3.6% and 0.8% after co-process domestic waste, respectively. Furthermore, compared with sanitary landfill treatment, the co-processing in cement kiln will increase the impact of FFP, but reduce GWP and HTP impacts, especially significantly decrease the impact of LOP and SOP, bring in a good beneficial on material saving and energy saving.
Recent Developments on Life Cycle Assessment of Building Materials
Authors: Liu Ning , Liu Yu , Gong Xian Zheng , Hao Li Wei , Gao Feng , Li Xiao Qing , Zheng Yan
Published: May 2020

In recent years, the building materials industry in China has made great progress in the R&D of energy conservation, emission reduction and cleaner production technologies, in order to implement sustainable development policy. Life cycle assessment (LCA) is one of the mainstream method to analyze the environmental impact of product during its life cycle, which plays an important role on ecological design of building materials and development of green manufacture technology in recent year. This paper reviewed the LCA studies of building materials. Firstly, the development of China's building materials industry and technical framework of LCA standardized by ISO14040/14044 were introduced. Moreover, the typical LCA case studies of cement, glass, ceramics, wall materials, insulation materials and other building materials were reviewed. At last, some prospects for future research and development in this field were put forward.
Carbon Emissions Analysis of Rock Wool Board Products
Authors: Huang Meng Chi , Zhang Yan Jiao
Published: May 2020

Green building materials have drawn more and more attention of the Chinese Government. Carbon footprint research on typical building materials products in China is of great significance to promote the sustainable development of building materials industry and realize the objectives of series actions on carbon dioxide emissions control in China. This paper explores the calculation method for carbon emissions of building materials products by taking rock wool sheet products as an example based on the life cycle idea and the characteristics of China's building materials industry. It also puts forward effective emission reduction suggestions through a comparative analysis of carbon emissions in different stages of rock wool production. The results show that the carbon emissions during the production of rock wool sheet is 1471.77 kgCO2eq/t, in which, the proportion of carbon emissions in the raw materials production stage is the highest, accounting for 58%.
Study on Compression-Torsion Deformation Behavior and Recrystallization Grain Size of Mg13Gd4Y2Zn0.5Zr Alloy
Authors: Xu Ping , Yu Jian Min , Zhang Zhi Min , Liu Kai
Published: May 2020

In this paper, the compression-torsion composite deformation of homogenized Mg-13Gd-4Y-2Zn-0.5Zr alloy with strain rate of 0.001 s-1-0.5 s-1 during the temperature interval of 350 °C-480 °C was studied by the torsional test using the equipment of Gleeble3500 unique to North University of Chain. The effects of temperature and strain rate on the flow behavior of the alloy during compression-torsion deformation were investigated. And the compression-torsion constitutive equation of the high temperature flow stress of the alloy was constructed by introducing the temperature compensation factor Z, providing a theoretical basis for subsequent finite element analysis. The results showed that the flow stress increased with the increase of strain when the flow curves of the alloy were 350 °C and 400 °C. When the deformation temperatures were 450 °C and 480 °C, the flow stress was a typical recrystallization type. The influence of temperature and strain rate on dynamic recrystallization behavior was investigated by OM observation. The results showed that the number and size of recrystallized grains increased with the increase of temperature at the same strain rate, and the number and size of recrystallized grains increased with the decrease of strain rate at the same temperature.
Microstructural Evolution and Properties of Cu-1.5 Wt %Ti Alloy during Aging
Authors: Cheng Jian Yi , He Kun Zhe , Deng Ming Qiang , Yu Fang Xin
Published: May 2020

The microstructural evolution in Cu-1.5 wt % Ti alloy aged at 400 °C was investigated by high resolution electron microscopy (HREM). The hardness and electrical conductivity of this alloy have been also characterized. The electron metallographic results showed that the sequence of the decomposition in the studied Cu-1.5 wt % Ti alloy can be summarized as follows: a modulated structure resulting from spinodal clustering → formation of clusters and then ordered fcc phase → formation of LRO β’-Cu4Ti which distributed periodically along the <100>Cu directions. The ordered fcc phase showed a cube-on-cube OR with matrix, while the LRO β’-Cu4Ti showed an orientation relationship of [001]Cu//[001]β’ and (310)Cu//(100)β’. After aging for 24 h, the hardness and electrical conductivity of this alloy reached 175 HV and 25.3 % IACS, respectively. The spinodal clustering is responsible for the hardening of the alloy during the initial 30 min aging. The ordered fcc phase and β’-Cu4Ti phase makes a significant contribution to the strengthening of the alloy during the advanced stage of aging.
Microstructures and Mechanical Properties of a New Type of High Temperature Titanium Alloy
Authors: Cui Ya Peng , Chen Zi Yong , Ma Xiao Zhao , Liu Ying Ying , Xiang Zhi Lei , Chai Li Hua
Published: May 2020

The microstructures and mechanical properties of a new type near α high temperature titanium alloy Ti-6.5Al-2.5Sn-9Zr-0.5Mo-0.25Si-1Nb-1W-0.3Re (wt. %) (denoted as TA6.5) were investigated. It was observed that the microstructure of forged TA6.5 mainly consisted of deformed lamellar α phase, small amount of equiaxed α phase, and residual β phase, exhibiting high strength and comparatively low elongation. Three different heat treatments processes were performed on forged TA6.5. The results showed that all heat treated alloys displayed high tensile strengths, and the values of strength parameters were almost unchanged with the increasing solution temperature, ascribing to the combination effects of decreasing primary α phase and increasing contents and widths of secondary α phase and lamellas. The tensile elongations of heat treated alloys tested at 650 °C decreased slightly with the increasing solution temperature, which is due to the increased width of secondary α lamellas and the generation of coarse grain boundary α phase. TA6.5 treated in the process of 990 °C/1 h/AC+700 °C/4 h/AC exhibited excellent comprehensive mechanical properties, i.e. the ultimate tensile strength of 829 MPa, yield strength of 707 MPa and elongation of 18.73% respectively.
Effect of Primary α Phase Content on Creep Property of High Temperature Titanium Alloy
Authors: Wang Cong Cong , Li Bo Long , Qiao Xu , Wang Tong Bo , Qi Peng , Nie Zuo Ren
Published: May 2020

The effect of the primary α content and precipitate on the creep resistance of a high-temperature titanium alloy with a small amount of Hf addition were studied. The microstructures with different primary α contents were prepared by the heat treatment of 920~1010 °C /1 h+700 °C/5 h, and the creep test (600 °C/150 MPa/100 h) was carried out. The interaction between the precipitation phase and the dislocation configuration was analyzed. The results showed that with the increase of solution temperature, the volume fraction of primary α phase decreased from 44.9% at 920 °C to 0% at 1010 °C, and the steady state creep rate of the alloy decreased from 60.60×10-4%/h to 3.72×10-4%/h, indicating that the creep property was significantly improved with the decrease of solution temperature. The basket structure with optimal creep resistance was obtained under the heat treatment of 1010 °C/1 h+700 °C/5 h. It is believed that during the high temperature creep test, the precipitated α2 phase and the hafnium-containing silicide hinder the dislocation motion in α crystal and the phase boundary, thereby improving the creep resistance of the alloy.
Deoxidation Process of Oxidized Zirconium Alloy
Authors: Zhang Jun Song , Long Chong Sheng , Liao Jing Jing , Wei Tian Guo , Yang Zhong Bo
Published: May 2020

When zirconium alloy is corroded, an oxide film is formed on the surface, which hinders the ion transfer during the corrosion process. Therefore, the analysis of the oxide film is an important part of the research on the corrosion resistance of zirconium alloys. In this paper, two kinds of Zr-Sn-Nb alloys were corroded in 400 °C/10.3 MPa pure steam and 500 °C/10.3 MPa pure steam in autoclave to obtain samples with oxide thickness of 14 um and 18 um respectively. Then they were annealed at 800 °C at a pressure of 10-4 Pa for 18 h. XRD and WDS studies were used to analyze the structure and oxygen content of the oxide film after annealing. The results indicate that the oxide films of alloys change from zirconium dioxide to zirconium after annealing. The oxygen diffuses into the substrate and its content decreases continuously with increasing diffusion distance. Combined with the SEM analysis of cross-section samples, it is found that the annealed samples are composed of several layers. An oxygen-saturated zirconium layer, a transitional layer with micro-cracks, an oxygen-dissolved α-Zr layer and a β-Zr layer are identified. Based on these results, the mechanism of the ion transfer in the oxide film during annealing is analyzed deeply. It is proposed that space charges in the oxide film have a major impact on deoxidation kinetics. This study provides a new research method for the corrosion mechanism of zirconium alloys.
Hot Compressive Behavior and Constitutive Equation of Ti-Al-Nb-Zr-Mo-Cr Alloy
Authors: Zhu Li Wei , Xin Yun Peng , Wang Xin Nan , Zhu Zhi Shou
Published: May 2020

The hot deformation behavior of Ti-Al-Nb-Zr-Mo-Cr titanium alloy was studied by hot compressive method in this paper, and the flow stress constitutive equation and activation energy also calculated. The results show that the flow stress increased with deformation temperature dropping and strain rate increasing. The flow behavior of the sample hot-deformaed exhibited a peak value of stress in the α+β field, whereas, the true stress attained a steady state in the β field. According to the stress-strain curves of the alloy and its stress characteristics, the Arrhenius constitutive equation was obtained. The average activation energy was about 654.228 KJ/mol in the α+β field, and about 272.196 KJ/mol in the β field, respectively.
Constitutive Equation and Hot Processing Map for Tensile Test of Mg-13Gd-4Y-2Zn-0.5Zr Alloy at Elevated Temperature
Authors: Dong Bei Bei , Zhang Zhi Min , Yu Jian Min , Che Xin , Cheng Shao Bo
Published: May 2020

The high temperature tensile behavior of Mg-13Gd-4Y-2Zn-0.5Zr alloy was investigated at deformation temperature of 400-520 °C and strain rate of 0.001-0.5 s-1, and the stress-strain curves were obtained by using INSTRON 3382. The high temperature tensile constitutive model and hot processing map of the alloy were established, and the reliability of the hot processing map was further verified by analyzing the microstructure of the deformed alloy. The results showed that the dynamic recrystallization (DRX) occurred of Mg-13Gd-4Y-2Zn-0.5Zr alloy during the tensile tests under high temperature conditions, and its peak stress decreased with the increase of deformation temperature or strain rate. The Arrhenius equation can be used to fit the rheological behavior of the alloy. The thermal deformation activation energy Q was 259.13kJ/mol, and the maximum error between the model and the experimental data was less than 9%. It can be concluded that the optimum deformation parameters of the alloy were temperature of 500-520 °C and strain rate of 0.01-0.001 s-1 based on the dynamic material model and hot processing map.
Effect of Different Deformation Methods on Microstructure Evolution of TC4 Titanium Alloy Prepared by Spark Plasma Sintering
Authors: Xue Yong , Yan Jiang Peng , Fan Hong Zhi , Liu Hai Jun , Zhang Zhi Min , Xu Jian
Published: May 2020

TC4 titanium alloy powder was made into the test piece by spark plasma sintering. The hot deformation of TC4 titanium alloy was performed on the Gleeble-1500 experiment machine. The effects of microstructure were studied. The results show that the number of passes increased with the increasing of the relative density at the same amount of deformation. The relative density have an important influence in one-pass deformation. At the deformation temperature of 950°C and a strain rate of 0.1s-1, the microstructure of TC4 titanium alloy was the weave-basket structure, and the widmanstatten structure existed. The increase in the number of passes could promote the growth of dynamic recrystallization grains under the same amount of deformation.
Solidification Microstructure and Mechanical Properties of Bulk Near-Eutectic AlCoCrFeNi2.2 High Entropy Alloy
Authors: Huang Xuan , Hu Yao , Wu Zhang Tong , Dong Yong , Li Chuan Qiang , Cheng Yong Qi , Zhang Zheng Rong
Published: May 2020

A 4Kg grade AlCoCrFeNi2.2 high entropy alloy was prepared by low vacuum medium frequency induction melting. The microstructure results showed that the microstructure and composition of the ingot were uniform. The microstructures were composed of primary Ni-rich FCC phase and eutectic structure. The eutectic structure was composed of Ni-rich FCC phase and Al-rich B2 phase. The hardness results showed no significant difference in Vickers hardness between different parts of the ingot, and fluctuated within the range of HV260 ± 20. The compression test results showed that there was no significant difference in compression performance between different parts of the ingot. The AlCoCrFeNi2.2 high entropy alloy had excellent compression performance, the yield strength reached 600 MPa, the fracture strength reached 2200 MPa, and the compression ratio was greater than 40%. Above all, the near-eutectic AlCoCrFeNi2.2 high-entropy alloy had the characteristics of good casting ability, high strength, good plasticity, and was easy to realize the preparation of large-volume non-segregation ingot.