Function Of Processing Temperature Research Articles

Effect of H3PO4 content and processing temperature on the structure and mechanical properties of porous Si3N4

Open-porous silicon nitride ceramics have been fabricated via low-temperature processing at 1200 °C using phosphoric acid as an inorganic binder and pore-forming agent. A detailed study of the effect of phosphoric acid content on the microstructure development and an in-depth analysis of the influence of the porosity and pore morphology on compressive strength, flexural strength, and notch-root radius corrected fracture toughness has been performed. Further, the progressive evolution of porosity and the amount and type of crystalline phases as a function of processing temperature were studied by intermittent XRD analysis. For the first time, a detailed analysis of the pore structure evolution on the longitudinal elastic constant of the porous samples was studied using a non-destructive ultrasonic technique. The critical H3PO4 content of 40 vol% yielded a homogeneous nanoporous structure that resulted in the best mechanical properties – compressive strength >120 MPa, flexural strength >70 MPa, and a notch-root radius corrected KIC ∼1 MPa m1/2. Despite the low fabrication temperature and economic processing route, the mechanical properties of the fabricated porous samples are comparable to the values for porous Si3N4 reported in the literature.

Expanded Glass for Thermal and Acoustic Insulation from Recycled Post-Consumer Glass and Textile Industry Process Waste

The production of glass foams obtained by recycling post-consumer glass and textile industry processing waste is presented. The mechanical, thermal and acoustic properties were characterized as a function of process temperature and time. The results showed that it is possible to produce glass foams with thermal and acoustic insulation properties from a mixture consisting of 96.5% of glass waste, 1% of textile waste and 2.5% of manganese dioxide, processed at temperatures between 800 and 900 °C for a time between 30 and 90 min. The samples had density in the range of 200-300 kg m-3, porosity of 87-92%, thermal conductivity of 85-105 mW m-1 K-1, noise-reducing factors of 0.15-0.40 and compressive strength of 1.2-3.0 MPa. Although their insulation performance was not as outstanding as that of polymer foams, these materials can emerge as competitive candidates for applications requiring non-flammability and high-temperature load bearing capacity in combination with low weight, mechanical strength, and thermal and acoustic insulation properties. The use of secondary raw materials (which accounted for 97.5% by weight of the synthetic blend) limits the energy required compared to that needed for the extraction, transportation and processing of primary raw materials, making these foams attractive also in terms of environmental footprint.

A systematic analysis of maximum tolerable tool wear in friction stir welding

Friction stir welding (FSW) is a solid-state joining process with a wide range of applications in the E-mobility, automotive, aerospace and energy industries. However, FSW is subjected to specific challenges including comparatively high process forces and high requirements on the clamping technique as well as tool wear resulting from the tool-workpiece interaction and thermo-mechanical stresses. Geometric-related tool wear can cause premature tool failure, process instabilities or weld seam irregularities. Therefore, tool wear in general, wear limits and tool life are essential factors for the efficient and sustainable implementation of friction stir welding. Against this background, this study analysed areas of significant tool wear on the shoulder and probe as a function of process temperature, weld seam length and weld seam quality. This provided functional correlations for determining limiting conditions on maximum tolerable tool wear. Geometrical deviations of the tool, induced by wear, were detected experimentally at different measuring points on the probe and shoulder and varying weld seam length. The investigations were carried out using a force-controlled robotized welding setup in which AA-6060-T66 sheets with a thickness of 5 mm were joined by weld seams up to 500 m in length. To identify the maximum tolerable tool wear, the weld seam properties were determined by visual and metallographic inspections and by tensile tests at 50-m intervals on the weld seam. It was shown that a 50% reduction in rotational speed (lower temperatures) resulted in less wear and thus in an increase of tool life of up to 150%. In addition, it was shown that the shoulder, like the probe, was also subject to significant wear. These results can be incorporated into FSW maintenance schedules to maximize tool life and minimize scrap rates.

PyVaporation: A Python Package for Studying and Modelling Pervaporation Processes

PyVaporation—a freely available Python package with an open-source code for modelling and studying pervaporation processes—is introduced. The theoretical background of the solution, its applicability and limitations are discussed. The usability of the package is evaluated using various examples of working with and modelling experimental data. A general equation for the representation of a component’s permeance as a function of feed composition, temperature and initial feed composition is proposed and implemented in the developed package. The suggested general permeance equation may be used for the description of an extremal character of permeance as a function of process temperature and feed composition, allowing the description of processes with a high degree of non-ideality. The application of the package allowed modelling experimental points of various sets of hydrophilic pervaporation data and data on membrane performance from independent sources with a relative root mean square deviation of not more than 9% for flux and not more than 5% for a separated mixture concentration. The application of the facilitated parameter approach allowed the prediction of the components’ permeance as a function of feed concentration at various initial feed concentrations with a relative root mean square error of 3–26%. The package was proven useful for modelling isothermal and adiabatic time and length-dependent pervaporation processes. The comparison of the models obtained with PyVaporation with models provided in the literature indicated similar accuracy of the obtained results, thereby proving the applicability of the developed package.

Intelligent modeling and optimization of titanium surface etching for dental implant application

Acid-etching is one of the most popular processes for the surface treatment of dental implants. In this paper, acid-etching of commercially pure titanium (cpTi) in a 48% H2SO4 solution is investigated. The etching process time (0–8 h) and solution temperature (25–90 °C) are assumed to be the most effective operational conditions to affect the surface roughness parameters such as arithmetical mean deviation of the assessed profile on the surface (Ra) and average of maximum peak to valley height of the surface over considered length profile (Rz), as well as weight loss (WL) of the dental implants in etching process. For the first time, three multilayer perceptron artificial neural network (MLP-ANN) with two hidden layers was optimized to predict Ra, Rz, and WL. MLP is a feedforward class of ANN and ANN model that involves computations and mathematics which simulate the human–brain processes. The ANN models can properly predict Ra, Rz, and WL variations during etching as a function of process temperature and time. Moreover, WL can be increased to achieve a high Ra. At WL = 0, Ra of 0.5 μm is obtained, whereas Ra increases to 2 μm at WL = 0.78 μg/cm2. Also, ANN model was fed into a nonlinear sorting genetic algorithm (NSGA-II) to establish the optimization process and the ability of this method has been proven to predict the optimized etching conditions.

Tube equal channel angular extrusion (tECAE) of Mg–3Al–1Zn alloy

This study describes a severe plastic deformation processing technique for tubular materials, in the interest of enhancing mechanical properties via grain refinement and crystallographic texture control. The process, dubbed as tube equal channel angular extrusion (tECAE), is used to process the Mg–3Al–1Zn (AZ31) magnesium alloy at low temperatures. Mg alloys often suffer from low strength levels derived from coarse grain size, strong crystallographic texture, and mechanical anisotropy; hence, AZ31 acts as an ideal candidate for tECAE, as AZ31 and other Mg alloys tubes have excellent potential application in various industries. Here, the texture evolution of one pass of tECAE processing at 200 °C, 175 °C, and 120 °C was assessed, where tECAE produced drastically refined grains and increased strength levels after only one pass. The texture evolution and the active deformation modes, and their relative activities, were successfully predicted using a viscoplastic self-consistent (VPSC) crystal plasticity model as a function of processing temperature, for the first time for the tECAE process. Overall, tECAE is shown to be a useful technique for quickly obtaining improved mechanical properties in Mg alloy tubes, and it can be applied to other materials in tubular form as well. • Tube ECAE processing successfully produced fine grained Mg-3Al-1Zn tubes. • Tube ECAE SPD processed AZ31 directly at 120 °C. • Improvement in mechanical properties and texture modification are obtained via tECAE. • VPSC modeling predicted texture and deformation mode activities.

Controlled Methodology for Development of a Polydimethylsiloxane-Polytetrafluoroethylene-Based Composite for Enhanced Chemical Resistance: A Structure-Property Relationship Study.

Polydimethylsiloxane (PDMS) polymers are highly appreciated materials that are broadly applied in several industries, from baby bottle nipples to rockets. Momentive researchers are continuously working to understand and expand the scope of PDMS-based materials. Fluorofunctional PDMS has helped the world to apply in specialty applications. Efforts are taken to develop such siloxane–fluoropolymer composite materials with good thermal, solvent, and chemical resistance performances. We leveraged inherently flexible PDMS as the model matrix, whereas polytetrafluoroethylene (PTFE) was used as the additive to impart the functional benefits, offering great value in comparison to the individual polymers. The composites were made at three different mixing temperatures, that is, 0–35 °C, and different loadings of PTFE, that is, 0.5–8% (w/w), were selected as the model condition. A strong dependency of the mixing temperature against the performance attributes of the developed composites was noted. Mechanical and thermal stability of the composites were evaluated along with optical properties. X-ray diffraction demonstrated the change in the crystallite size of the PTFE particles as a function of processing temperature. Compared to the phase II crystallite structure of the PTFE, the fibrils formed in phase IV imparted a better reinforcing capability toward the PDMS matrix. A synergistic balance between higher filler loading and mechanical properties of the composite can be achieved by doping the formulation with short-chain curable PDMS, with 238% increment of tensile strength at 8 wt % PTFE loading when compared to the control sample. The learning was extended to check the applicability of doping such PTFE powder in commercial liquid silicone rubber (LSR). In the window of study, the formulated LSR demonstrated improved mechanical properties with additional functional benefits like resistance toward engine oil and other chemical solvents.

Growth characteristics of tin sulphides crystals by the vapour transport method using SnS and sulphur powders: effect of temperature and pressure

Tin sulphide compounds have two different types of 2D layered crystal structures with different electrical conduction types. Tin disulphide with n-type semiconductor characteristics has a 2D crystal structure with hexagonal symmetry, while tin monosulphide (SnS) with p-type semiconductor characteristics has a 2D crystal structure with orthorhombic symmetry. These layered materials have many potential applications such as electronic and optoelectronic devices. Meanwhile, it is known that the growth products of tin sulphides are very sensitive to the process parameters. In this study, the authors investigated the growth phenomena of tin sulphides by the vapour transport method using SnS and sulphur powders because vapour transport reactions are relatively simple and facilitate the understanding of the effects of growth parameters. The growth behaviour of tin sulphides as a function of process temperature and pressure was observed, and the results can be explained in terms of the sulphurisation and reduction of SnS powder during the growth process.

Understanding microstructural evolution and hardness of nanostructured Fe89.5Ni8Zr2.5 alloy produced by mechanical alloying and pressureless sintering

Fe89.5Ni8Zr2.5 alloy was synthesized by mechanical alloying followed by pressureless sintering at various temperatures up to 900 °C. Microstructural evolution as a function of processing temperature was characterized using focused ion beam microscopy, transmission electron microscopy and X-ray diffraction techniques. The dependence of hardness on the microstructure was utilized to study the mechanical changes. The experimental results showed that microstructural stability can be enhanced by segregation of solutes to grain boundaries at low temperatures and by precipitation of second phases at elevated temperatures. Eventually, at higher processing temperatures the stability was lost due to the coarsening of the precipitated second phases leaving behind ultra-fined grained microstructure. Despite the coarsening of the grain size with increasing processing temperatures, the in-situ formed second phases were found to induce an Orowan strengthening effect leading to approximately 5.5 GPa hardness after 1 h sintering at 900 °C.

The Biotic and Abiotic Carbon Monoxide Formation During Aerobic Co-digestion of Dairy Cattle Manure With Green Waste and Sawdust.

Carbon monoxide (CO), an air pollutant and a toxic gas to humans, can be generated during aerobic digestion of organic waste. CO is produced due to thermochemical processes, and also produced or consumed by cohorts of methanogenic, acetogenic, or sulfate-reducing bacteria. The exact mechanisms of biotic and abiotic formation of CO in aerobic digestion (particularly the effects of process temperature) are still not known. This study aimed to determine the temporal variation in CO concentrations during the aerobic digestion as a function of process temperature and activity of microorganisms. All experiments were conducted in controlled temperature reactors using homogeneous materials. The lab-scale tests with sterilized and non-sterilized mix of green waste, dairy cattle manure, sawdust (1:1:1 mass ratio) were carried out for 1 week at 10, 25, 30, 37, 40, 50, 60, 70°C to elucidate the biotic vs. abiotic effect. Gas concentrations of CO, O2, and CO2 inside the reactor were measured every 12 h. The CO concentrations observed for up to 30°C did not exceed 100 ppm v/v. For 50 and 60°C, significantly (p < 0.05) higher CO concentrations, reaching almost 600 ppm v/v, were observed. The regression analyses showed in both cases (sterile and non-sterile) a statistically significant effect (p < 0.05) of temperature on CO concentration, confirming that the increase in temperature causes an increase in CO concentration. The remaining factors (time, O2, and CO2 content) were not statistically significant (p > 0.05). A new polynomial model describing the effect of temperature, O2, and CO2 concentration on CO production during aerobic digestion of organic waste was formulated. It has been found that the proposed model for sterile variant had a better fit (R2 = 0.86) compared with non-sterile (R2 = 0.71). The model predicts CO emissions and could be considered for composting process optimization. The developed model could be further developed and useful for ambient air quality and occupational exposure to CO.

Ultrathin Solar Absorber Layers of Silver Bismuth Sulfide from Molecular Precursors.

Here we present a robust molecular precursor-based approach to synthesize high-quality thin films of silver bismuth sulfide (AgBiS2). Pure-phase cubic AgBiS2 thin films are prepared, which are smooth and dense down to thicknesses less than 40 nm. Comprehensive structural and morphological analysis of the as-prepared films as a function of processing temperature and composition is presented, including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The optical properties of the films and their electronic bandstructure are also presented. The as-prepared films show impressive light absorption properties with absorption coefficients reaching 105 cm-1 for energies above ca. 950 nm. Finally, their photoactivity is demonstrated through photoconductivity measurements on lateral electrodes. The methods outlined herein enable the fabrication of AgBiS2 semiconductor thin films at low processing temperatures (150 °C) with a dense morphology and tunable Ag/Bi composition. Such films provide an excellent platform for the fabrication of AgBiS2-based optoelectronic devices, specifically solar cells.

Hybrid Carbon Nano-Fibers with Improved Oxidation Resistance

Hybrid Carbon-Silicon Carbide (C-SiC) nano-fibers were fabricated while using a mixture of polyacrylonitrile (PAN) and silicon (Si) nanoparticles as precursors. The microstructure of the material was examined using X-ray diffraction and Raman spectroscopy as a function of processing temperature and holding time. A complete transformation of Si to SiC occurred at 1250 °C. However, for heat treatments below 1000 °C, three distinct phases, including Si, C, and SiC were present. The effect of microstructural changes, due to the heat treatment, on oxidation resistance was determined using thermogravimetric analysis (TGA). Furthermore, the char yield showed exponential growth with increasing the carbonization temperature from 850 °C to 1250 °C. The holding times at higher temperatures showed a significant increase in thermal properties because of SiC grain growth. At longer holding times, the SiC phase has the function of bothcoating and reinforcing phase. Such structural changes were related to fibers mechanical properties. The tensile strength was the highest for fiber carbonized fibers at 850 °C, while the modulus increased monotonically with increasing carbonization temperature.

Erbium-doped chalcogenide glass thin film on silicon using femtosecond pulsed laser with different deposition temperatures

The properties of Er3+-doped gallium lanthanum sulphide thin films prepared on a silicon substrate by femtosecond pulsed laser deposition were studied as a function of process temperature. The films were characterised using transition electron microscopy imaging, X-ray diffractometry, Raman spectroscopy, fluorescence spectroscopy, and UV–Vis–NIR spectroscopy. The results show that by increasing the substrate temperature, the deposited layer thickness increases and the crystallinity of the films changes. The room temperature photoluminescence and lifetimes of the 4I13/2→4I15/2 transition of Er3+ are reported in the paper.

3D printing of asphalt and its effect on mechanical properties

The paper describes work to design, build and test an asphalt 3D printer. The main difficulty encountered is that asphalt behaves as a non-Newtonian liquid when moving through the extruder. Thus, the rheology and pressure in relation to set temperature and other operational parameters showed highly non-linear behaviour and made control of the extrusion process difficult. This difficulty was overcome through an innovative extruder design enabling 3D printing of asphalt at a variety of temperatures and process conditions. We demonstrate the ability to extrude asphalt into complex geometries, and to repair cracks. The mechanical properties of 3D printed asphalt are compared with cast asphalt over a range of process conditions. The 3D printed asphalt has different properties from cast, being significantly more ductile under a defined range of process conditions. In particular, the enhanced mechanical properties are a function of process temperature and we believe this is due to microstructural changes in the asphalt resulting in crack-bridging fibres that increase toughness. The advantages and opportunities of using 3D printed asphalt to repair cracks and potholes in roads are discussed.

Low-Temperature-Processing of Printed Cathodes for Aqueous Metal-Air Batteries

Developing low cost energy storage for integrated electronic applications depends on the ability to increase energy densities while reducing materials and manufacturing costs. Metal-air batteries are an emerging solution for next-generation energy storage given their superior theoretical energy storage capacity and use of low cost, earth abundant, and lightweight anode materials such as Zn, Al, and Mg. While metal-air batteries offer significant promise, inefficiencies at the air cathode dominate cell performance and limit practical energy densities. Recent studies in metal-air batteries have introduced new electrocatalysts to improve cathodic efficiency, but often rely on elevated temperatures and prolonged processing times to achieve suitable performance. Thus, rapid synthesis of air cathodes at low temperatures remains a significant challenge for mass production of metal-air batteries. In this work, we establish a printed air cathode architecture that can be fabricated below 100 °C, broadening the potential applications for metal-air batteries by lowering overall manufacturing costs and improving process compatibility for integrated systems. Furthermore, we investigate the importance of binder, solvent, and catalyst interactions and their influence on air cathode performance in a primary Zn-air battery. Additive manufacturing is used to demonstrate high throughput deposition and high accuracy patterning of metal-air battery materials. Stencil printing is chosen as a proof of concept technique to assemble the air cathode and Zn-air battery. Analogous to screen printing, stencil printing is capable of achieving thick active layers (10s-100s µm) for high capacity electrodes and is compatible with a variety of substrates including silicon wafers and flexible plastics. Cathode inks using polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE) were compared to study the effects of the binder and associated solvent on the oxygen reduction reaction (ORR) as a function of processing temperature. Using a commercially available carbon powder with a platinum catalyst, cathodic half-cells were constructed to measure cell impedance and ORR overpotential as a function of binder material and annealing temperature. Thermogravimetric analysis (TGA) and x-ray photoelectron spectroscopy (XPS) were used to identify compositional changes, in both the cathode inks and printed films, related to solvent evaporation and binder degradation during annealing. Moreover, in operando pressure decay and differential electrochemical mass spectroscopy (DEMS) measurements were conducted to determine ORR efficiencies for the printed cathodes. After characterizing the printed air cathodes, printed Zn-air full-cells were fabricated to demonstrate the dependence of cell performance on binder type and annealing temperature. Higher operating voltages at a given current density were observed in cells with the PTFE binder compared to the PVDF binder, with the PTFE cells maintaining operating voltages above 1 V at current densities up to 24 mA cm-2. As a result, the PTFE cells exhibited peak power densities between 25-30 mW cm-2 at annealing temperatures as low as 80 °C, compared to 12 mW cm-2 at 350 °C for the PVDF cells. PTFE cells also displayed internal resistances less than 50 Ω with areal capacities between 2-5 mAh cm-2 with platinum concentrations as low as 5 wt%. This work represents the first demonstration of a low temperature printed air cathode for metal-air batteries. Our printed cathodes are broadly applicable to other aqueous metal-air battery systems and present a novel solution to fabricating low cost, high energy density batteries. The cathode inks are also compatible with several high throughput patterning techniques, including screen printing and slot-die coating, and could help achieve greater penetration of energy storage in emerging applications such as wearable and flexible electronics.

Rheological, mechanical and morphological properties of poly(butylene adipate-co-terephthalate)/thermoplastic starch blends and its biocomposite with babassu mesocarp

Poly (butylene adipate-co-terephthalate)/thermoplastic starch (PBAT/TPS) blends and a PBAT/TPS/babassu mesocarp biocomposite were prepared by melt mixing in a torque rheometer at different processing temperatures (150, 170, 190 °C). Tensile test specimens were obtained by hot pressing. Torque rheometry indicated that molecular weight decreased with increasing processing temperature and TPS content in the blend, and this decrease was more intense with babassu mesocarp addition. PBAT mechanical properties were hardly affected by processing temperature while those of the blends decreased with thermoplastic starch content. Overall, increasing processing temperature led to lower mechanical properties, particularly at 190 °C. Fiber addition led to higher modulus and lower strength and elongation at break than the corresponding blend at all processing temperatures investigated. The differences observed on blend morphology as a function of processing temperature were minor. Some adhesion between TPS and PBAT is observed but adhesion between polymer matrix and babassu fibers is essentially non-existent.

Self-assembled 3D zinc borate florets via surfactant assisted synthesis under moderate pressures: Process temperature dependent morphology study

In the present study, we prepared zinc borates using aqueous phase synthesis under moderate pressures (MP) (<150 psi) with ethanol as a co-solvent in the presence of a quaternary ammonium surfactant-Cetyltrimethylammonium bromide (CTAB). 3D morphologies of self-assembled zinc borate (Zn(H2O)B2O4 · 0.12 H2O, Zn3B6O12 · 3.5H2O, ZnB2O4) resembling flower-like structures were obtained by varying temperature under moderate pressure conditions. Synthesized zinc borates’ florets were morphologically characterized by Field Emission Scanning Electron Microscopy. The x-ray diffractions of borate species reveal rhombohydra, monoclinic and cubic phases of zinc borate crystals as a function of process temperature. Additionally, thermal analysis confirms excellent dehydration/degradation behavior for the zinc borate crystals synthesized at moderate pressures and elevated temperatures and could be utilized as potential flame retardant fillers in the polymer matrices.

Entrained-flow gasification of torrefied tomato peels: Combining torrefaction experiments with chemical equilibrium modeling for gasification

The purpose of the present study is to quantify the impact of torrefaction pretreatment on the quality of the product gas arising from the gasification with steam and steam-oxygen mixtures of non-woody biomass in high-temperature entrained flow reactors. To this aim, a chemical equilibrium model for biomass gasification was adopted, which allowed predicting the product gas composition as a function of process temperature, equivalence ratio, steam-to-biomass ratio and biomass elemental composition. A global sensitivity analysis with respect to the model input parameters was performed to assess the impact of torrefaction and gasification operating conditions on the quality of the product gas in terms of heating value and composition metrics typically adopted in the process industry (H2/CO ratio, stoichiometric module, etc.). In particular, the gasification of raw tomato peels and related torrefied solids resulting from fluidized bed torrefaction tests performed under light (200 °C and 30 min), medium (240 °C and 30 min) and severe (285 °C and 30 min) conditions was investigated using ultimate analysis data in the model. Results of this analysis highlighted that the quality of product gas arising from the oxygen-steam gasification of torrefied and untreated tomato peels did not differ very much, although torrefied feedstocks produced more H2 and CO and less CO2 than the parent one. This suggests that, despite the significant benefits it determines in biomass feeding, grinding and storage, the torrefaction pretreatment provides only a marginal improvement in the product gas quality. Equilibrium simulations made available in the present study can be useful for a better understanding of the controlling variables that rule gasification processes in addition to act as a point of reference for more complex simulations of the high temperature entrained flow gasification of biomass with oxygen-steam mixtures.

A physiochemical processing kinetics model for the vapor phase infiltration of polymers: measuring the energetics of precursor-polymer sorption, diffusion, and reaction.

Vapor phase infiltration (VPI) is a new approach for transforming polymers into organic-inorganic hybrid materials with unique properties. Here, we combine experimental measurements with phenomenological theory to develop a universal strategy for measuring, modeling, and predicting the processing kinetics of VPI. We apply our approach to the well-studied VPI system of trimethylaluminum (TMA) infiltrating poly(methyl methacrylate) (PMMA) because the system undergoes both precursor-polymer diffusion and reaction. By experimentally measuring aluminum concentration profiles as a function of film depth with secondary ion mass spectrometry (SIMS) and film swelling with ellipsometry, we have extracted equilibrium solubility and effective diffusivity as a function of process temperature. Fitting these values to appropriate Van't Hoff and Arrhenius relationships, we can then extract enthalpies for precursor sorption and diffusion. We observe an abrupt mechanistic change in both the sorption and diffusion processes around 95 °C, where greater chain mobility at higher processing temperatures lead to greater reactivity between TMA and PMMA. With new understanding of this VPI process, we demonstrate precise control of inorganic infiltration depth and loading fraction into PMMA.

Investigation of reaction mechanisms in the chemical vapor deposition of al from DMEAA

We propose a novel reaction scheme for the chemical vapor deposition (CVD) of Al films on substrates from dimethylethylamine alane (DMEAA), supported by the prediction of the Al deposition rate as a function of process temperature. The scheme is based on gas phase oligomerizations of alane which form a substantial amount of intermediates. Combined with reversible surface dehydrogenation steps, the global deposition reaction is composed of a set of 12 chemical reactions. This new scheme entails four intermediates and includes side reactions that play an important role in the formation of Al thin films. The chemistry mechanism is incorporated in a 2D Computational Fluid Dynamics (CFD) model of the CVD reactor setup used for the experimental investigation. The simulation predictions of the Al deposition rate are in good agreement with corresponding experimental measurements. The success of this novel reaction pathway lies in its ability to capture the abrupt decrease of the deposition rate at temperatures above 200 °C, which is attributed to the gas phase consumption of alane along with its increased desorption rate from the film surface.