Effect of alternate magnetic field on LY12 structure properties after thermal plastic forming

The powerful alternate magnetic field treatment is an effective not-heat treatment, which improves the coriaceous performance of the material. In order to reveal the effect rule of the powerful alternate magnetic field on the structure capability after thermal plastic forming, the experimental methods were adopted to compare the microcosmic structure of the LY12 aluminium alloy test pieces before and after the powerful alternate magnetic field treatment. The mechanism of the structure refining was analyzed theoretically. According to the effect rule of the alternate magnetic field on critical grain growth work and the magnetic vibration-constriction mechanism, the structure dynamics factors were analyzed. The results show that, after a certain powerful alternate magnetic field treatment, the mechanical capability of the LY12 aluminium alloy after thermal plastic forming can be reinforced, the structure intertwist deriving from the thermal plastic forming becomes even and the branch crystal is also smashed, consequently refines the structure. The powerful alternate magnetic field treatment can be regarded as an effective method to improve metal structure performance after heat plastic forming.

Effects of Metal Absorber Thermal Conductivity on Clear Plastic Laser Transmission Welding

In our previous study, metals have been used as absorbers in the clear plastic laser transmission welding. The effects of metal thermal conductivity on the welding quality are investigated in the present work. Four metals with distinctly different thermal conductivities, i.e., titanium, nickel, molybdenum, and copper, are selected as light absorbers. The lap welding is conducted with an 808 nm diode laser and simulation experiments are also conducted. Nickel electroplating test is carried out to minimize the side-effects from different light absorptivities of different metals. The results show that the welding with an absorber of higher thermal conductivity can accommodate higher laser input power before smoking, which produces a wider and stronger welding seam.The positive role of the higher thermal conductivity can be attributed to the fact that a desirable thermal field distribution for the molecular diffusion and entanglement is produced from the case with a high thermal conductivity.

ANALYSIS ON THERMAL ELASTO-PLASTIC ASPERITY CONTACTS OF LAYERED MEDIA

A thermal elasto-plastic asperity contact model is investigated, which takes into account the steady-state heat transfer and the asperity distortion due to thermal elasto-plastic deformations. A hard coating and a soft coating are applied to study the correlations between contact area and contact pressure, average gap and contact pressure, coating thickness and contours of the contact stress distribution, etc. The effects of material properties, coating thickness, frictional coefficient, and the heat input combinations on the stress distribution are investigated and discussed. The frictional heat input increases the maximum value of yon Mises stress. Finally, the appropriate thickness of the hard coating is also discussed. To protect the substrate, one can choose hard coating and the thickness of that is suggested that can be hc=70 Rm.

THERMAL AND THERMO-ELASTIC-PLASTIC RESPONSE OF CERAMIC-METAL FUNCTIONALLY GRADED MATERIALS—THERMAL SHOCK PROBLEM

The thermal and thermo-elastic-plastic response of newly developed ceramic-metal functionally graded materials under a thermal shock load is studied. The materials are heated at the ceramic surface with a sudden high-intensity heat flux input, and cooled at the metal surface with a flowing liquid nitrogen. Emphasis is placed on two aspects: (1) the influence of the graded composition of the materials on the temperature and stress response; and (2) the optimum design of the graded composition from a unified viewpoint of the heat insulation property and stress relaxation property. Moreover, a comparison between the thermoelastic stress and the thermo-elastic-plastic stress is also made to indicate the plasticity effect.

Alternative Diesel Grade Fuel Transformed from Polypropylene (PP) Municipal Waste Plastic Using Thermal Cracking with Fractional Column Distillation

Day by day worldwide use of plastics is increasing because of their light weight and durable characteristics. Waste plastics are major environmental problems all over the world. Waste plastics are not bio-degradable, it remains in the landfill for a long period of time causing vegetation and aquatic ecosystem dilemmas. Abandoned waste plastic thrown into the ocean causes friction of ocean waves and then broken down by sunlight into small pieces and takes the shape of plastic like soup. Aquatic organism mistakes the plastic soup as their food and can’t digest, either they die or through food chain it affects human health. To avoid severe environmental degradation problems of waste plastics some countries and big cities banned or restricted the use of plastic products. The worldwide generation of waste plastics is approximately 280 million tons/year. All most all of these waste plastics are dumped either in land or ocean. City municipalities spend huge amount of money each year just to dispose of these waste plastics into landfill because most waste plastics are not recycled. When the waste plastics are subjected to incineration, they release harmful toxic gas into the environment causing severe pollution. These waste plastics gradually enhance the hazardous environmental problems. Generally plastics are made from crude oil, however crude oil is a very limited natural resource and non-renewable. Every year millions of barrels of crude oil are to produce the waste plastics and when plastics are discarded after use the energy source is lost. A new developed technology plan minimizes the environment pollution problems simultaneously boost up energy sector by renovating the waste plastics into high energy content fuel. The produced fuel is obtained using a unique thermal degradation of waste plastics and converting them into hydrocarbon fuel like materials. Preliminary tests proved that this fuel burns cleaner and the production cost is very low. Unique production setup demonstrated to produce 93% fuel from waste plastic in the pilot scale. The Fuel produced has been tested and proven to work on majority types of internal combustion engines. This technology utilized can avoid waste plastic pollution problem worldwide by the implementation of newly developed technology. Through the utilization of the technology the use of reliable plastics won’t need to be banned and serve as a very reliable alternate source of energy. The technology will also help reduce a significant amount of import oil from foreign countries and help provide a steady economy.

Thermal Resistance of Graphite Plastics Based on Aromatic Polyamide

The paper presents the results of studying graphite plastics based on heat-resistant polyamide by thermogravimetric analysis (TGA), as well as the determination of mechanisms and kinetic parameters by the Koats-Redfern method. Based on the results of the thermal analysis, the mechanisms and kinetic parameters of the thermal destruction process were determined, namely: graphite injection increases the heat resistance of graphite plastics by 2 (graphite content 10% by weight) - 22% (graphite content 50% by weight) and reduces the activation energy of the process thermal destruction almost 2 times. This makes it possible to improve the technological parameters for the production of polymeric composite materials, which are limited by a narrow interval between the flow temperatures and the thermal destruction of phenylone C-2.

Research Progress of Thermal Conductive Plastics on High Thermal Conductivity

In this paper, the research progress of thermal conductive plastics at present is summarized from the categories of thermal conductive plastics, the advantages of thermal conductive plastics over other thermal conductive materials, several common preparation methods of thermal conductive plastics and the key problems in future research.The problems found in the process of summarizing are discussed and prospected.

Plastic Sealed Thermal Expansion Packer for Thermal Recovery

ＰｌａｓｔｉｃＳｅａｌｅｄＴｈｅｒｍａｌＥｘｐａｎｓｉｏｎＰａｃｋｅｒｆｏｒＴｈｅｒｍａｌＲｅｃｏｖｅｒｙ￥ＬｉｕＬｉａｎｄＪｉａｎｇＨｕａ（ＯｉｌＲｅｃｏｖｅｒｙＴｅｃｈｎｉｑｕｅＤｅｐａｒｔｍｅｎｔ，ＬｉａｏｈｅＰｅｔｒｏｌｅｕｍＡｄｍｉｎｉｓｔ...

A New Kind of Renewable Energy: Production of Aromatic Hydrocarbons Naphtha Chemical by Thermal Degradation of Polystyrene (PS) Waste Plastic

Polystyrene (PS) waste plastic to renewable energy or naphtha grade fuel production through fractional distillation process was applied and PS liquefaction temperature range was 250?C - 430?C and fractional column temperature was 110?C - 135?C for naphtha grade fuel separation. The thermal degradation of PS waste plastic to renewable energy or naphtha grade chemical production was without adding any kind of cracking catalyst and without vacuum system. Polystyrene waste plastic is not bio-degradable and its can remain long period of landfill and creating gas emission for that reason its major cause climate change. For experimental purpose raw sample was use 1 kg of PS waste plastic and experiment was performed under Labconco fume hood and experiment was fully closed system, whole experiment was performed into stainless steel reactor. Produced fuel was analysis by gas chromatography and mass spectrometer, FT-IR and DSC. Analysis result indicate for fuel compounds chemical structure, compound band energy and enthalpy, delta H value. Produced fuel sulfur content less then environmental protection agency (EPA) level and fuel could be use for chemical feedstock refinery for further modification. By using this technology can reduce some foreign oil dependency and boost up renewable energy sector all over the world.

Thermal decomposition and kinetics of plastic bonded explosives based on mixture of HMX and TATB with polymer matrices

This work describes thermal decomposition behaviour of plastic bonded explosives(PBXs) based on mixture of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX) and 2,4,6-triamino-1,3,5-trinitrobenzene(TATB)with Viton A as polymer binder. Thermal decomposition of PBXs was undertaken by applying simultaneous thermal analysis(STA) and differential scanning calorimetry(DSC) to investigate influence of the HMX amount on thermal behavior and its kinetics. Thermogravimetric analysis(TGA) indicated that the thermal decomposition of PBXs based on mixture of HMX and TATB was occurred in a three-steps. The first step was mainly due to decomposition of HMX. The second step was ascribed due to decomposition of TATB, while the third step was occurred due to decomposition of the polymer matrices. The thermal decomposition % was increased with increasing HMX amount. The kinetics related to thermal decomposition were investigated under non-isothermal for a single heating rate measurement. The variation in the activation energy of PBXs based on mixture of HMX and TATB was observed with varying the HMX amount. The kinetics from the results of TGA data at various heating rates under non-isothermal conditions were also calculated by Flynn—Wall—Ozawa(FWO) and Kissinger-Akahira-Sunose(KAS)methods. The activation energies calculated by employing FWO method were very close to those obtained by KAS method. The mean activation energy calculated by FWO and KAS methods was also a good agreement with the activation energy obtained from single heating rate measurement in the first step decomposition.

Techno-Economic Evaluation of Thermal and Catalytic Pyrolysis Plants for the Conversion of Heterogeneous Waste Plastics to Liquid Fuels in Nigeria

Techno-economic potentials of thermal and catalytic pyrolysis plants for the conversion of waste plastics to liquid fuels have been widely studied, but it is not obvious which of the two plants is more profitable, as the existing studies used different assumptions and cost bases in their analyses, thereby making it difficult to compare the economic potentials of the two plants. In this study, industrial-scale thermal and catalytic waste plastics pyrolysis plants were designed and economically analyzed using ASPEN PLUS. Amorphous silica-alumina was considered the optimum catalyst, with 3:1 feed to catalyst ratio. Based on 20,000 tons/year of feed and 20% interest rate, the catalytic plant, having a net present value (NPV) of &#83582208 million, was found to be economically less attractive than the thermal plant, having the NPV of &#83582426.4 million. On the contrary, sensitivity analyses of the two plants at a feed rate of 50,000 tons/year gave rise to a slightly higher NPV for the catalytic plant (&#83589861 million) than the thermal plant having NPV of &#83589838 million, thereby making the former more economically attractive for processing large amounts of waste plastics into liquid fuels. Consequently, as the catalytic plant showed a better scale economy and would produce higher quality liquid fuels than the thermal plant, it is recommended for commercialization in Nigeria.

Small-angle X-ray analysis of the effect of grain size on the thermal damage of octahydro-1, 3, 5, 7-tetranitro-1, 3, 5, 7 tetrazocine-based plastic-bounded expolsives

The microstmcture evolution of plastic-bonded explosives （PBXs） after thermal stimulus plays a key role in PBX performance. In this paper, the nanoscale pores of thermal-treated octahydro-1,3,5,7-tetranitro-1,3,5,7 tetrazocine （HMX）- based PBXs with different HMX particle sizes [approximately 40 （FLIP） and 100 μm （LHP）] were measured using small- angle X-ray scattering （SAXS）. No obvious pore variations were found in the LHP samples heated at 160 ℃ for 6 h, whereas the amount of pores of FHP decreased when subjected to 160 ℃ for 6 h. At 180 ℃, the average pore radii of FHP and LHP decreased from approximately 45 nm to 25 nm, and the total pore volume increased distinctively because of phase transformation. The LHP sample reached a high level of pore content after being held at 180 ℃ for 1 h, whereas FHP required 3 h. Both FHP and LHP had relatively high pore volumes when subjected to 200 ℃ for 1 and 3 h.

A Review of the Life Cycle Analysis for Plastic Waste Pyrolysis

Pyrolysis is a rapidly expanding chemical-based recyclable method that complements physical recycling. It avoids improper disposal of post-consumer polymers and mitigates the ecological problems linked to the production of new plastic. Nevertheless, while there is a consensus that pyrolysis might be a crucial technology in the years to come, more discussions are needed to address the challenges related to scaling up, the long-term sustainability of the process, and additional variables essential to the advancement of the green economy. Herein, it emphasizes knowledge gaps and methodological issues in current Life Cycle Assessment (LCA), underlining the need for standardized techniques and updated data to support robust decision-making for adopting pyrolysis technologies in waste management strategies. For this purpose, this study reviews the LCAs of pyrolytic processes, encompassing the complete life cycle, from feedstock collection to end-product distribution, including elements such as energy consumption, greenhouse gas emissions, and waste creation. Hence, we evaluate diverse pyrolysis processes, including slow, rapid, and catalytic pyrolysis, emphasizing their distinct efficiency and environmental footprints. Furthermore, we evaluate the impact of feedstock composition, process parameters, and scale of operation on the overall sustainability of pyrolysis-based plastic waste treatment by integrating results from current literature and identifying essential research needs. Therefore, this paper argues that existing LCA studies need more coherence and accuracy. It follows a thorough evaluation of previous research and suggests new insights into methodologies and restrictions.

Effect of Polyethylene Terephthalate Plastic Waste on the Physico-Mechanical and Thermal Characteristics of Stabilized Laterite Bricks

The present work investigated the effect of polyethylene terephthalate (PET) plastic waste on the physico-mechanical and thermal properties of cement-stabilized laterite bricks to see the durability of the modified bricks (CSLB). Samples were formulated by mixing laterite, cement, and different percentages of PET (0%, 3%, 5%, and 7%) by volume. The bricks were produced using the M7MI Hydraform standard interlocking block and kept in the shade for a curing period of 28 days. The addition of 3% to 5% PET to the laterite stabilized with 10% cement results in a decrease in both dry and wet compressive strength, which is determined using the Controlab compression machine. However, the obtained results are in concordance with the standards. The thermal conductivity of CSLB, determined using the box method with the EI700 measurement cell, decreases as the PET content of the mixture increases. A decrease in bulk density from 1.67 to 1.58 g/cm3 was observed.

Development of a Thermoplastic Magnesia Carbon Brick ——“A Cold Process Flexible System”

Conventional resin bonded MgO-C bricks, which are manufactured via cold mixing process, harden and attain brittleness during carbonization of resin due to the formation of isotropic glassy carbon. They do not exhibit thermo-plasticity, which can facilitate the release of huge amount of stresses generated during preheating or in operation. On the contrary, pitch bonded MgO-C bricks, show better pyro-plasticity due to formation of an anisotropic and graphitized coke structure during carbonization of pitch. Hence, pitch bonded bricks show a superior structural spalling resistance in comparison to resin-bonded bricks. One of the drawbacks of pitch-bonded bricks is that the manufacturing requires a hot mixing process and hot pressing facility. This paper describes how a combination of above two processes was optimized to make a MgO-C brick via cold process. These bricks exhibit a low Modulus of Elasticity and thereby facilitate release of stresses during operation. Normal coal tar pitch is considered as an environmental hazard due to the presence of polyaromatic hydrocarbons like benzopyrene B [ a ] P. So, a special binder with a low B[ a ] P was selected, which is eco-friendly in nature. Such bricks were made in our plant in China and supplied to an integrated steel plant in Europe for their ladle. The bricks supplied have given encouraging life.

可降解塑料包装袋土埋降解性能研究

目的塑料污染已成为全球环境污染的一个突出问题,对新型绿色生物可降解塑料的需求不断增加。为评估不同生物可降解材料在土壤环境中的降解性能,并探讨加速材料降解的主要因素。方法设计一系列土埋实验,模拟材料在自然环境中的土壤条件。实验使用淀粉+聚乙烯(PE)、聚乳酸(PLA)+聚己二酸-对苯二甲酸丁二酯(PBAT)+淀粉、聚对苯二甲酸丁二酯(PBT)+聚乳酸(PLA)+玉米基材以及高密度聚乙烯(HDPE)+细胞外基质(ECM)降解母料,并以聚乙烯(PE)作为对照组。通过改变埋土深度、土壤湿度和土壤pH值等实验条件,结合傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、热力学分析等技术,探究不同材料的降解速率、降解性能差异以及材料分子结构可能的变化。结果研究表明,样品的结晶度显著影响其降解性能。尤其是PLA+PBAT+淀粉样品,由于分子间作用力增强和热触发运动性能的降低,在实验中表现出较低的最大失重速率和较高的失重峰温,表现出最高的热稳定性和最佳的降解性能。结论样品表现出良好的热稳定性和降解性,为生物可降解塑料的开发和应用提供了科学依据,有助于解决塑料污染问题。

热解技术在油田含油废塑料处理中的应用

油田含油废塑料存在热解易结焦、处置达标率低等难题。塔河油田借鉴含油污泥处置经验,通过引进连续回转窑热解吸处理装置,在国内首创含油污泥与含油废塑料协同处理模式,实现了含油废塑料的高效处置。本文着重研究连续回转窑工艺参数对含油废塑料热解残渣含油率及热解油回收率的影响,实验结果表明:当m(含油废塑料):m(含油污泥)=1:3时,其混合物料最优热解吸温度为600℃、热解吸时间为120 min,无害化处理后热解残渣含油率、热解油回收率最优。

Numerical simulation of thermal stress field for die casting dies of aluminum alloy

The thermal elastic plastic constitutive equations suitable for computation of thermal stress of die casting dies were established. On the base of simulation of temperature field, the thermal stress field of die casting dies was simulated by COSMOS, and the effects of initial die temperature and coating on the surface of die on thermal stress distribution were studied. The results show that the thermal stress mainly concentrates on the die surface and the lower initial die temperature and no thermal resistance cause a higher thermal stress. [