Pack Process Research Articles

Modeling thermal runaway propagation of lithium-ion batteries under impacts of ceiling jet fire

Thermal runaway (TR) of lithium-ion batteries (LIBs) is always accompanied by the emission of combustible gases and the resulting jet fire may promote TR propagation in the battery module. An accurate TR propagation model incorporating jet fire provides insights into the cell-to-cell failure mechanism and aids the safety-optimal design of battery pack. In this work, a modeling framework based on conjugate heat transfer is developed to explore the interaction between jet fire and propagation behavior during TR. The LIBs are modelled by integrating chemical reactions, gas generation and jet dynamics, while the jet fire outside the cells is simulated by the CFD models involving combustion. The heat balance is employed to address TR propagation, which fully considers the energy flows between various elements of battery pack. The proposed model is capable of capturing the flame morphology and temperature evolution of cells, fire and ceiling plate, as confirmed by the TR propagation experiment under ceilings. Simulation results demonstrate that increasing the space confinement degrees shortens the propagation time interval by enhancing the convection from ejected gases and the radiation from flame. The reduction of ceiling height extends the flame extension length and significantly accelerates the cell-to-cell failure, highlighting the impacts of jet fire on TR propagation. This work presents a more realistic model for TR propagation, which can provide a pragmatic guidance for the battery pack's fire protection design and process safety assurance in the practical application.

Characterization of Boride Coatings on AISI 8620 Steels without and with Hydrogen Permeation

The present work studied the characterization of boriding coatings without and with exposed hydrogen permeation on AISI 8620 through microstructure and mechanical behavior. A dehydrated paste pack process was carried out for the formation of boride coatings on AISI 8620 at 1173, 1223, and 1273 K for 6 h of exposure time for each temperature. After boronizing, hydrogen was introduced into the borided steels by in situ cathodic charging using an H2SO4 acid electrolyte. Specimens borided without and with hydrogen were characterized by scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction. The experimental techniques of the Vickers microhardness and three-point bending were used. As a result, the hydrogen diffusion on steel AISI 8620 borided shows a significant increase in microhardness. Furthermore, three-point bend tests showed an increased strength on 8620 steel borided. However, the ductility and strength value on 8620 steel borided surfaces presented a drastic reduction due to hydrogen permeation. The results revealed that the borided coatings provided strength and reduced the hydrogen embrittlement index on AISI 8620 borided.

Analysis of Shunted Screen Gravel Pack Process and Calculation of Friction in Deepwater Horizontal Wells

Shunted screen gravel packing is a kind of technology which is difficult to complete gravel packing with the conventional method in low fracture pressure formation and long wellbore length condition. According to the characteristics of LS 17-2 deepwater gas field, the shunted screen packing tool was designed and the gravel packing process and packing mechanism were analyzed. The variation law of the flow friction, flow rate distribution in multichannel, and other parameters of the shunted screen gravel packing were analyzed and calculated. The friction calculation model of different stages of gravel packing was established. A gravel packing simulation software was developed to simulate the friction in different stages of shunted screen gravel packing. The parameters such as sand-dune ratio, pumping sand amount, packing length, and packing time in the process of packing were also calculated. In deepwater horizontal well gravel packing, the results show that the friction ratio of the string is the largest in the stage of injection and α-wave packing. While the friction increases rapidly in the stage of β-wave packing because the carrier fluid needs to flow through the long and narrow washpipe/screen annulus. Particularly when the β-wave packing is near the beginning of the open hole, the packing pressure reaches the maximum. The calculated results are in good agreement with the measured results of the downhole pressure gauge. The model and software can provide technical support for the prediction and optimization of gravel packing parameters in the future.

PENGARUH VARIASI SUHU DAN MEDIA PENDINGIN PADA PROSES PACK NITRIDING MATERIAL SUS 630 TERHADAP NILAI KEKERASAN DAN STRUKUR MIKRO

This research investigates the application of material engineering techniques on Stainless steel SUS 630 so that it not only has good resilience and resistance to corrosive properties but also has hard properties on its surface. In an effort to improve the quality of violence on the surface, among others, by surface hardening technique, one of which is a heat treatment technique by adding nitrogen elements to the surface of a material called the nitriding pack process. The nitrogen source in the pack nitriding process comes from urea (CO(NH2)2) with a nitrogen content of 46%. Parameters for controlling this study using variables by applying temperature variations (4200C, 4700C, 5200C, 5700C, 6200C) and cooling media (inside the furnace, room temperature, and with fan) with a holding time of 2 hours. To evaluate this study microstructure testing, diffusion layer testing and micro hardness testing were carried out. From the results of the test it was found that there was no significant transformation of the microstructure shape when comparing with raw material, the optimal value of diffusion layer was in the cooling furnace with a temperature of 6200C with an average of 4.57 μm and white layer 0.53 , the highest hardness was at 6200C with cooling in furnace media which has a value of 80.9 HRN.

Queuing system behaviour in thermo pack process

The Queuing model introduced here defines a batch arrival model with the extra assumption of stages of service. In addition, the system deploys a set up time stage for the pre-processing work to be carried out, which is essential for the stages of service. In addition, we introduce a new factor Reneging that occurs twice in this model during the setup time stage and also during the t7]=, ZO, WZ]pu[sZry, v(W(t7ZJi, RustZ]=r’s, (rr7v([, follows a Poisson distribution, while the service rendered follows a general distribution. Here, we carry out the concept of Compulsory vacation as a maintenance work duration, which helps to reduce the occurrence of service interruption. The model is well elucidated with thermo pack process from mechanical engineering. Thermo pack is the machine that is used as a boiler. Generally, we raise the temperature of oil in the thermo pack. The working principle of the thermo pack is similar to that of an ordinary boiler. It can raise the temperature of the oil from the initial temperature along with the temperature of oil which has been already used once. After the production of hot oil, it is allowed to flow around the mould to keep up the temperature inside the mould. In other cases, this oil can also be used for refining purposes. Nowadays, recent advancements in the thermo pack have led to the creation of new and advanced small size thermo pack for small-scale production. The procedure completed in this structure is considered through Queuing hypothesis. The above process comprises queuing parameters like set up time, stages of process, compulsory vacation process and the concept of types of Reneging. The Queuing issue emerges in the above auxiliary technique is understood by valuable variable strategy. The probability of creating capacity of the line size, duration of line, the number of clients in the framework, holding up time of the clients in the line just as in the framework, usage factor and the inert time of the server are inferred. Numerical delineation and a broadened graphical assessment are undertaken around the conclusion to help the model.

Fatigue Strength Improvement of Low Carbon Steel through Carburizing Process with Coconut Shell Charcoal

The fatigue strength of low carbon steel is a limitation that is often considered in machine construction, especially in rotating component parts. Low carbon steel has special properties that are soft, good welding and good machining, as well as relatively inexpensive prices but have low fatigue strength. For this reason, in this study, a carburizing process was carried out with the media of coconut shell charcoal as a source of carbon and shell powder as a catalyst. The addition of carbon using the carburizing method is relatively easy and does not require a large cost because the materials used are abundant in nature. The carburization process was carried out at 950°C for 4 hours. Furthermore, mechanical properties were tested with hardness, tensile testing and fatigue testing. The carburization process with charcoal media is expected to increase hardness, tensile strength and fatigue strength. Fatigue testing is carried out by the reverse bending method with a load varying 70%, 60%, 50% and 45% of the tensile strength of the material. In addition, microstructure examination and fault surface observation are also carried out to analyze the phenomenon of changes in material structure due to carburization. The hardness value of ST37 steel before carburizing ie 118 HRB increased to 127 HRB after undergoing carburizing treatment. Tensile test results also experienced an increase in which the initial tensile strength value of ST37 steel by 356.66 MPa increased to 541.15 MPa after the carburizing process. Likewise in fatigue testing, the fatigue limit has increased significantly, where the ST37 steel fatigue limit before the carburizing pack is at a stress level of 161 MPa. After experiencing the carburizing pack process the ST37 steel fatigue limits are at a voltage level of 232 MPa.

Pengaruh pack carburizing media arang tempurung kelapa terhadap ketahanan aus baja komersial dengan variasi pelumas.pdf

This research was conducted to determine the effect of carburizing pack of charcoal shell on commercial wear resistance of steel with variation of lubricant. Carbon used is coconut shell charcoal. Carburizing pack process is done at temperature 950oC with quenching water medium and tempering with temperature 200oC, after carburizing pack process then do wear wear with variation of SAE 40 oil, SAE 90, SAE 140 and also without lubricant (TP). The wear rate on specimens undergoing carburizing process for SAE 40 and SAE 90 testing was 0.08% with wear factor of 0.00193 mm3 / N.km and 0.00202 mm3 / N.km, then for SAE 140 test the wear rate 0.05% and wear factor of 0.00128 mm3 / N.km, as well as for non-lubricant testing (TP) of 0.31% and wear factor of 0.00807 mm3 / N.km. While testing of raw material at SAE test 40 wear rate and wear factor 0,19% and 0,00504 mm3 / N.km, for SAE 90 test result 0,21% and 0,00541 mm3 / N.km, and result Wear rate of SAE 140 test equal to 0,0,18% with wear factor 0,00459 mm3 / N.km then testing without lubricant (TP) equal to 3,59% with wear factor equal to 0,09537 mm3 / N.km.

Characterization of Coatings Obtained by Boriding Niobizing Treatment of an AISI H13 Steel

Wear is responsible for numerous industrial problems leading to increased maintenance costs due to the necessity of replacing worn components or due to equipment failure and manufacturing process downtime. Surface treatments can improve performance because the component maintains its ductile interior but with significantly improved surface wear resistance while using a minimal amount of material. Niobizing the surface of tool steel leads to the formation of very hard coatings, in the range of 2300 HV, composed of niobium carbide but with limited thickness. Boriding also produces very hard coatings, on order of 2000 HV, but with a much thicker layer than attainable by the niobizing treatment. If both were applied to the same material they could potentially complement each other by forming a duplex coating with a thin, but very hard, surface coating supported by an inner layer with slightly lower hardness but substantially thicker. The objective of this work was to evaluate the wear resistance of a coating formed by the niobizing and boriding diffusion treatments. Boron and niobium coatings were prepared on AISI H13 tool steel by thermo-reactive diffusion treatment in molten borax with 10 wt% aluminum followed by the niobium carbide pack process. The boriding treatment was performed at 900°C for 2 h, followed by a pack process at 1000°C for 2, 4, and 6 h. Optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, micro-adhesive wear test, and Vickers micro-hardness were used to analyze the samples. The boriding and niobium carbide pack process produced coatings with thicknesses above 45 and 4 μm, respectively.

Similarity Based Approach for Comparing Home Healthcare Processes Models in Portugal

Similarity metrics applied to business processes are used to compare and assess the similarities and differences between a set of process models. The results of this comparison can then serve as input to take management decisions, such as to prevent the proliferation of process variants. This is particularly useful in large (enterprise or governmental) organizations with multiple organizational units that share the same business processes. Examples include faculties of a university and their student enrollment process, hospitals or primary care centers of National Health Services and their medical appointment process, or even the pick and pack process across several warehouses of a large company. Due to many aspects (i.e. local policies, resources, socio-technical aspects, culture), a certain business process is individually evolved and refined across the multiple organizational units of the same organization. Organizations have then to deal with several process variants, which hampers the collection of performance indicators, optimization procedures and business process management overall. In this paper, we perform a similarity based approach to assess the similarities and differences that exist between home healthcare processes for two public primary healthcare centers in Portugal. We will achieve this by eliciting business process models according to best practices. Then, we lead a similarity based comparison between the elicited models. This is in order to show how much models are different in the same organization.

Microstructural Characterization of Silicide Coatings on Mo and TZM Alloy

Characterization of microstructure of silicide coatings obtained during diffusion process of pack cementation type was showed in this article. The basic materials were pure Mo sheet and TZM molybdenum alloys as well. The coatings were deposited in out of pack process with three different times of exposure. The temperature of deposition process was constant. In first step the phases compositions of coatings was described by XRD analysis. In each cases the MoSi2 phase was obtained on top surface of the coatings. The morphology of the coatings was very similar as well. All types of coatings were characterized by network of cracks on top surface of the coatings. There was no influence of depositions time on phases constituent and coatings topography. LM and SEM analysis revealed that internal coatings morphology was very similar in all cases. Basic differences was related to the thickness of coatings. All coatings were good quality without deep cracks. Microstructure was a columnar-like type without pores and voids.

Comparative tribological studies of duplex surface treated AISI 1045 steels fabricated by combinations of plasma nitriding and aluminizing

Duplex surface treatments via aluminizing and plasma nitriding were carried out on AISI 1045 steel. A number of work pieces were aluminized and subsequently plasma nitrided (Al–PN) and other work pieces were plasma nitrided and then aluminized (PN–Al). Aluminizing was carried out via pack process at 1123K for 5h and plasma nitriding was performed at 823K for 5h. The fabricated steels were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and microhardness testing. Tribological behaviors of the duplex treated AISI 1045 steels were examined against tungsten carbide pin using a pin-on-disc apparatus at room temperature. The PN–Al specimen showed higher surface hardness, lower wear rate and coefficient of friction than the Al–PN one. It was noticed from the worn surfaces that tribo-oxidation plays an important role in wear behavior of both specimens.

High temperature oxidation protection of Ti3Al-based alloys with different Nb-content by a combined Al-/F-treatment

ABSTRACTOrthorhombic titanium-based Ti2AlNb alloys cannot be used above a temperature limit of about 800°C due to accelerated oxidation and environmental embrittlement. This embrittlement is caused by the high oxygen solubility which deteriorates the mechanical properties. Even if these materials possess an Al content up to ca. 25at.% no protective alumina layer is formed. Instead a non-protective fast growing mixed scale is found. Several attempts have been made to increase their operation temperature e.g. by coatings but none has proven sufficiently protective so far. One new way presented in this paper is to enrich Al in a narrow surface zone by using a powder pack process (aluminization) followed by a fluorination step. Exposure tests at elevated temperature have shown that the aluminized specimens form an alumina layer during exposure in oxidizing environments. Due to the gradient in the Al-concentration interdiffusion with the substrate and the Al-rich diffusion zone occurs which lowers the Al concentration in the diffusion zone. If the Al content drops below a critical value, Ti oxides will also form, which deteriorates the protection provided by the alumina scale. The subsequent fluorination triggers the fluorine effect which stabilizes the protective alumina layer. Untreated specimens are covered with a thick non protective scale and exhibit oxygen ingress in the subsurface zone while treated specimens reveal a thin protective alumina layer and no inward diffusion of oxygen. In this paper results of exposure tests of untreated and treated orthorhombic Ti2AlNb alloys will be presented and compared with the Nb-free α2-phase Ti3Al and Nb-containing Ti3Al-based alloys.

Improving high temperature oxidation and hot corrosion resistance of Ni-base super alloy INC738LC with Cr-Si-RE modified aluminide coatings produced by single step pack cementation process

The Cr-Si-Zr (or Y) modified aluminide coatings were produced on Ni-base INC738 by a novel single step pack cementation process and their behavior was evaluated in cyclic oxidation and hot corrosion conditions. A dual layer pack with different composition was applied to produce Cr-Si-Zr or Cr-Si-Y modified aluminide coatings. A mixture of salts 75%Na2SO4-20%NaCl-5%V2O5 at 950°C was used as a hot corrosion environment. The results show that oxidation and corrosion rate of Cr-Si-Zr or Cr-Si-Y modified aluminide coatings produced by dual layer pack process are lower than those of uncoated or simple aluminide coatings. Coatings with higher Al content and uniformly dispersed Cr-Si rich phases show better hot corrosion resistance.

Extended system design for RFID enabled supply chains with non-RFID technologies

Currently, the coordination between supply chain participants is normally organised via a scan packing system and communicated through electronic data interchange technology. However, the scan pack process is costly and time consuming. Using the electronic product code technology defined by EPCglobal, two national demonstrator projects have been developed to explore the suitability of RFID to the fast moving consumer goods supply chain. The projects show that two major issues must be addressed for RFID technology to be used effectively in global supply chains. First, small and medium enterprises using different RFID standards are unable to participate. Second, RFID IT infrastructures are rigid and costly. This paper examines the capability of two new mobile technologies in relation to current RFID system designs and experiences in the national projects. An extended RFID system is proposed to enable these non-RFID technologies to be used in conjunction with EPC-based systems so that links to non-RFID sites can be established and the cost of system implementation can be more affordable.

Adhesion and wear properties of boro-tempered ductile iron

In this study, adhesion and wear properties of boro-tempered ductile iron (BDI) were investigated. Boro-tempering was carried out on two stage processes i.e. boronizing and tempering. At the first stage, ductile iron samples were boronized by using pack process at 900 °C for 1, 3, and 5 h and then, secondly tempered at 250, 300, 350, and 400 °C for 1 h. X-ray diffraction (XRD) analysis of boro-tempered samples showed that FeB and Fe 2B phases were found on the surface of the samples. The Daimler-Benz Rockwell-C adhesion test was used to assess the adhesion of boride layer. Test result showed that adhesion decreased with increasing boriding time and increased with increasing tempering temperature. Dry sliding wear tests of these samples were performed against Al 2O 3 ball at a constant sliding speed and loads of 5 and 10 N. Wear tests indicated that boro-tempering heat treatment increased wear resistance of ductile iron. In addition, it was found that while wear rate of boro-tempered samples decreased with increasing boriding time, there is no significant affect of tempering temperature on wear rate.

Combined Al‐ plus F‐treatment of Ti‐alloys for improved behaviour at elevated temperatures

AbstractTitanium is a widely used structural material because of its low specific weight, good mechanical properties and excellent corrosion resistance at ambient temperature. As a result of increased oxidation at elevated temperatures and environmental embrittlement the maximum operation temperature of standard Ti‐alloys is only about 600 °C. The oxidation behaviour can be improved by different methods, e.g. coatings. This leads to an improvement which is, however, often limited. The combination of Al‐enrichment in the sub surface zone, so that a TiAl‐layer is formed, plus F‐treatment gives impressively good results because a protective alumina scale is formed due to the fluorine effect. This alumina scale prevents oxygen inward diffusion which causes embrittlement and protects the material against environmental attack. The procedure is applied to alloys with a very low Al‐content or even no Al at all. In the paper results of oxidation tests of α‐Ti without any treatment, with Al‐treatment and with a combination of Al‐ + F‐treatment are presented. Aluminium was diffused into the samples by a powder pack process. Fluorine was applied by a liquid phase process. The formation of an alumina scale on treated samples was revealed by post experimental investigations. The results are discussed referring to the fluorine effect model for TiAl‐alloys.

EFFECT OF AL CONTENT ON MICROSTRUCTURE AND PROPERTIES OF AN INTERMETALLIC Ni-Ti (Al) COMPOUND/Ni GRADED COATING DEPOSITED ON COPPER SUBSTRATE

Copper and its alloys with high electrical and thermal conductivity are a group of widely used engineering materials in numerous applications. In order to improve the tribological properties of copper substrate, an electroplating nickel layer was firstly deposited on copper substrate, subsequently these electroplated specimens were treated by slurry pack cementation process at 900°C for 12 h using a slurry mixture composed of TiO 2 as titanizing source, pure Al powder as aluminzing source and also a reducer for titanizing, an activator of NH 4 Cl and albumen (egg white) as cohesive agent. The effect of Al content on the microstructure and the properties of the coating has been studied. The results showed that an intermetallic Ni - Ti ( Al ) compound/ Ni graded layer was formed on copper substrate after slurry pack cementation process. With the rise of Al content in slurry mixture, the microhardness of the graded coating increased and the friction coefficient decreased from 0.35 to 0.18, at the same time, the slurry pack process gradually transited from the titanizing process to an aluminizing one. Correspondingly the main phases of the coating were changed from Ni - Ti intermetallic compounds into Ni - Al ones.

Ultralow <inline-formula><math display="inline" overflow="scroll"><msub><mi>k</mi><mn>1</mn></msub></math></inline-formula> oxide contact hole formation and metal filling using resist contact hole pattern by double line and space formation method

It was shown previously that the double line and space formation method (DLFM) is superior to other methods for forming a dense contact hole (C/H) resist pattern by simulation, and a 0.30-k1 1:1 C/H resist pattern was formed experimentally. A through process of C/H formation from resist patterning to metal filling is presented. The oxide square C/Hs transferred from the resist pattern formed by the DLFM could be filled with metal, although the transferred C/Hs had square corners in comparison with the conventional C/H resist patterning. On the other hand, the combination of the DLFM and the “pack and cover process” makes it possible to form resist random C/Hs on grids. So, the possibility of forming random C/Hs filled with metal is shown. Moreover, the resolution limit of the DLFM is discussed. The 0.29-k1 (half pitch 65-nm) and 0.27-k1 (half pitch 56-nm) 1:1 C/H resist patterns could be formed with optimized dipole illumination. So, random C/Hs with k1 below 0.30 are expected to be formed.

Advanced Coatings on High Temperature Applications

To suppress interdiffusion between the coating and alloy substrate in addition to ensuring slow oxide growth at very high temperatures advanced coatings were developed, and they were classified into four groups, (1) the diffusion barrier coating with a duplex layer structure, an inner σ−(Re-Cr-Ni) phase as a diffusion barrier and outer Ni aluminides as an aluminum reservoir formed on a Ni based superalloy, Hastelloy X, and Nb-based alloy. (2) the up-hill diffusion coating with a duplex layer structure, an inner TiAl2 + L12 and an outer β-NiAl formed on TiAl intermetallic and Ti-based heat resistant alloys by the Ni-plating followed by high Al-activity pack cementation. (3) the chemical barrier coating with a duplex layer structure, an inner* γ + β + Laves three phases mixture as a chemical diffusion barrier and an outer Al-rich γ-TiAl as an Al reservoir formed by the two step Cr / Al pack process. (4) the self-formed coating with the duplex structure, an inner α-Cr layer as a diffusion barrier and an outer β-NiAl as an Al-reservoir on Ni-(2050)at% Cr alloy changed from the δ-Ni2Al3 coating during oxidation at high temperature. The oxidation properties of the coated alloys were investigated at temperatures between 1173 and 1573K in air for up to 1,000 hrs (10,000 hrs for the up-hill diffusion coating). In the diffusion barrier coating the Re-Cr-Ni alloy layer was stable, existing between the Ni-based superalloy (or Hastelloy X) and Ni aluminides containing 1250at%Al when oxidized at 1423K for up to 1800ks. It was found that the Re-Cr-Ni alloy layer acts as a diffusion barrier for both the inward diffusion of Al and outward diffusion of alloying elements in the alloy substrate. In the chemical barrier coating both the TiAl2 outermost and Al-rich γ-TiAl outer layers maintained high Al contents, forming a protective Al2O3 scale, and it seems that the inner, γ, β, Laves three phase mixture layer suppresses mutual diffusion between the alloy substrate and the outer/outermost layers.

Low k1 Contact Hole Formation by Double Line and Space Formation Method with Contact Hole Mask and Dipole Illumination

The double line and space (L&S) formation method was proved to have the capability to form contact hole (C/H) patterns with high resolution and wide process windows. The drawback of the method is its high cost. By replacing two L&S masks by one C/H mask with dipole illumination, high performance and mask cost reduction were targeted. The 75 nm (0.33-k1) 1:1 C/H pattern and the 70 nm (0.31-k1) 1:1 C/H pattern could be formed by the method using one C/H mask instead of two L&S masks. More than 300 nm depth of focus was obtained at 8% exposure latitude with 10% CD tolerance for the box windows both in the first-layer and the second-layer L&S resist patterns. To form a random C/H pattern on grids, a selective opening resist pattern was formed on the 1:1 C/H pattern. C/Hs were unearthed by the selective opening patterns with sufficient resist thickness for etching. Thus, random C/Hs on grids could be formed by the combination of the double L&S pattern formation method and the “pack and cover process”.