Evaporation Boat Research Articles

The Influence of Molasses Concentration on the Physical and Mechanical Properties of Evaporation Boat Waste-Based Crucibles

Crucibles are critical equipment utilized across numerous industries, and they are notably costly. In this study, the influence of molasses concentrations on the properties of crucibles fabricated from evaporation boat waste products is explored. The evaporation boat waste was powdered and filtered using a 100 mesh sieve. The molasses concentrations added during the mixing procedure were as follows: 0%, 5%, 10%, 15%, and 20% by weight. After 120 minutes, the mixture was compacted using 25 MPa pressure. The green body formed was dried at 100 ̊C for 300 minutes and fired at 1150 ̊C for 240 minutes. The obtained specimens were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), density testing, hardness testing, and flexural testing. The results of this study demonstrate that the addition of molasses has significant effects on the properties of the crucibles. Specimens using molasses with a concentration of 5 wt% produce better physical and mechanical properties than other specimens. The density, hardness, flexural strength, and weight percentages of Boron nitride (BN) and Titanium diboride (TiB2) phases in the specimen with 5 wt% molasses were 2.36 g/cm3, 64 HRA, 31.5 MPa, 68.9%, and 31.1%, respectively. The use of evaporation vessel waste and molasses in the production of crucibles in this study is in line with Sustainable Development Goals (SDGs) 3, 7, 14, and 15, which relate to improving excellent health and well-being, ensuring access to affordable energy, and conserving marine and terrestrial ecosystems.

Investigating the effect of molasses concentrations on the characterization of evaporation boat waste for crucible materials candidate

The crucible is a container wherein metallic materials are melted in order to generate new objects or alloys. Crucibles are typically formed of ceramic, graphite, silicon-carbide, and steel. Until now, there has been no study on the use of evaporation boat waste and molasses for the manufacture of crucibles. This study shows that molasses was used for binding the crucibles production formed from evaporation boats waste. The goal of this research was to ascertain how using molasses affected the properties of the crucible produced. Evaporation boat waste is made into powder (mesh 80) using a hammer mill. Molasses, evaporation boat waste powder and water with a certain concentration are mixed homogeneously using a mixer. The mixed material is put into a mold that has been adjusted to ASTM C1161-18, and then the compaction process is performed (20 MPa) to produce a green body. The resulting green body underwent a 16-hour drying time in an oven set at 100°C. Afterward, it was sintered for 240 minutes at 1150°C. The specimens in this study were characterized using XRD, SEM, density, hardness and 3-point bending tests. The test results show that molasses as a binder in the manufacture of crucible specimens does not result in the formation of a new crystalline phase. 5% molasses produced the best specimens. In specimens with 5% molasses, the density, hardness, flexural strength, and weight percentage (%) crystal phase of BN and TiB2 were 2.25 g/cm3, 61.6 HRA, 49.96 MPa, 67.5%, and 32.5%.

Deposition of Cu2ZnSnS4 layers by a novel single flash thermal evaporator from mixture element powder

This research studies the deposition ability of Cu2ZnSnS4 from a mixed element powder and without sulfurization by a novel flash single thermal evaporator technique. Elemental powders of the source, S, Sn, Zn, and Cu, are held in an evaporation boat to mix their vapour together and to evaporate the mixture at a high temperature. The effect of substrate temperature on the thin layers structure properties, optical properties and surface morphology is explored by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy dispersive X-ray, atomic force microscopy, and UV-Vis -NIR spectroscopy. Cu2ZnSnS4 films of kesterite structures are fabricated successfully at various substrate temperatures by this technique in one step without a sulfurization process. The substrate temperatures affect the composition and optical properties of the prepared layers by changing the concentration of elements and crystallinity. The layer prepared at 250°C exhibits an optimal stoichiometry and an optical bandgap value of 1.51 eV.

Effect of Firing Holding Time on Density, Porosity, and Hardness, Crucible Materials Based on Evaporation Boats

Evaporation boats are conductive advanced ceramic composites with the best thermal evaporation source for metalizing applications. The short life time of the evaporation boats causes the metalizing industry to produce large amounts of evaporation boats waste. However, studies on the utilization of evaporation boat waste are still limited. Therefore, this study aims to determine the effect of firing holding time on the density, porosity, and hardness of crucible materials made from evaporation boats waste. The material used in this research is a mixture of evaporation boats waste powder, kaolin, and graphite, with a composition of 50%, 25% and 25%, respectively. During the mixing process, 15% of the water is added. The compacting process carried out with a compaction pressure of 25 MPa. The firing process is carried out at a temperature of 1000<sup>o</sup>C with holding times of 60, 90, 120, 150, and 180 minutes. The test results show that the holding time of firing has an effect on density, porosity, and hardness. The highest density value was 1,91 g/cm<sup>3</sup> at a holding time of 180 minutes, and the lowest was 1,77 g/cm<sup>3</sup> at a holding time of 60 minutes. The highest porosity value is 4,10% at a holding time of 60 minutes, and the lowest is 2,16% at a holding time of 180 minutes. The highest hardness value was 12,84 HV at a holding time of 180 minutes, and the lowest was 8,3 HV at a holding time of 60 minutes. The longer holding time in the firing process results in a decrease in the porosity content. The decrease in the porosity content results in an increase in density and hardness of the cruicible specimens.

Pengaruh Waktu Pencampuran terhadap Kekerasan Vickers Material Crucible Berbahan Limbah Evaporation Boats, Kaolin dan Semen Tahan Api

Evaporation boat waste contains Boron Nitride (BN) and Titanium Diboride (TiB2) so that it has electrically conductive properties with high resistance to chemicals and heat. In addition, the combination of these materials has high thermal conductivity properties with a melting point of up to 2700oC and has an oxidation resistance of up to 1000oC so it is very suitable if applied to crucibles, or refractory. The purpose of this study was to determine the effect of mixing duration on the hardness of the crucible material made from a mixture of evaporation boats waste, kaolin and fire mortar SK-34. The mixing process of evaporation boats waste, kaolin and refractory cement is carried out using a mixer machine with a duration of 30, 60 and 90 minutes. The compaction process was carried out on the mixture with a force of 40 kg/cm2 to produce a cylindrical test specimen. After seven days, the specimens were sintered at 1000oC for 2 hours. The hardness test process was carried out with the FM-800 microhardness tester machine to determine the effect of mixing duration on the final product hardness. The highest hardness of 37,2 HV was found in the final product with a mixing duration of 90 minutes. The hardness of final product is increasing with an increase in mixing duration.

Pengaruh Thermal Shock dan Komposisi Evaporation Boats, Semen Tahan Api, dan Pasir Silika terhadap Kekuatan Impact dan Foto Makro Lining Refractory

<p>The thermal shock behavior of ceramic refractory materials is of particular interest. Refractory materials are submitted to local temperature gradients in service that originate thermal stresses and thermal shock damage to the material. However, thermal shock treatment on the refractory made from evaporation boat waste is not well documented. The purpose of this study is to determine the effect of thermal shock on the strength of refractory with various compositions. In this study, the refractory was made using 100% refractory cement (sample 1). For Sample 2, the refractory was made from a mixture of refactory cement and evaporation boats waste, each of 50%: 50%. Meanwhile, specimen 3 of the refractory is made from a mixture of refactory cement, evaporation boat waste, and silica sand of 40%: 50%: 10%, respectively. The Thermal shock treatment is carried out at a temperature range of 100 – 700<sup>o</sup>C for each specimen. The effect of thermal shock treatment on the mechanical properties of each refractory specimen was investigated using the impact and macrography test. Temperature variations in thermal shock have different effects on the level of impact strength on impact test specimens. The lowest strength was 0,012297735 J/mm<sup>2 </sup>at thermal shock 700<sup>0</sup>C in sample 3, and the highest impact strength was 0,03928934 J/mm<sup>2</sup> at 400<sup>o</sup>C thermal shock temperature in sample 2. The macrographic examination shows the higher the thermal shock temperature, the greater the fracture produced when the impact test is carried out. This is because the hardness of the refractory material increases.</p>

A comprehensive study of molybdenum boats behavior during service life for continuous thermal evaporation technique, used in thin film technology

The aim of this study is to calculate the optimum lifetime of Molybdenum (Mo) thermal evaporation boats for Copper (Cu) filling in thin film technologies. Three types of Mo boats with thicknesses of 0.2, 0.3 and 0.5 mm were used during the experiments under the high vacuum condition about 6.0 × 10−6 Torr. The behavior of each boat was investigated by focusing on the total amount of evaporation material, operational time and applied power. Prior to the deposition process, material was loaded on the evaporation boat by two methods. In the first method, Cu wire was cut into 1 cm long, then every boat was filled with this amount of Cu material. The second alternative feeding method is to use a wire-feeder step motor, which refills boat with Cu wire during evaporation process. The latter one is very useful for continuous deposition process since there is no need to break the vacuum state. In both methods, however, the number of failures during operations increases after a series of experiments have been taken place because of boat aging. The results of failures have been analyzed by various methods, and it has been observed that thinner boats showed better stability for long time operation by continuous feeding technique.

Realization of single-phase BaSi2 films by vacuum evaporation with suitable optical properties and carrier lifetime for solar cell applications

We have realized BaSi2 films by a simple vacuum evaporation technique for solar cell applications. X-ray diffraction analysis shows that single-phase BaSi2 films are formed on alkali-free glass substrates at 500 and 600 °C while impurity phases coexist on quartz or soda-lime glass substrates or at a substrate temperature of 400 °C. The mechanism of film growth is discussed by analyzing the residue on the evaporation boat. An issue on the fabricated films is cracking due to thermal mismatch, as observed by secondary electron microscopy. Optical characterizations by transmittance and reflectance spectroscopy show that the evaporated films have high absorption coefficients, reaching 2 × 104 cm−1 for a photon energy of 1.5 eV, and have indirect absorption edges of 1.14–1.21 eV, which are suitable for solar cells. The microwave-detected photoconductivity decay measurement reveals that the carrier lifetime is approximately 0.027 µs, corresponding to the diffusion length of 0.84 µm, which suggests the potential effective usage of photoexcited carriers.

Self catalytic growth of indium oxide (In2O3) nanowires by resistive thermal evaporation.

Self catalytic growth of Indium Oxide (In2O3) nanowires (NWs) have been grown by resistive thermal evaporation of Indium (In) in the presence of oxygen without use of any additional metal catalyst. Nanowires growth took place at low substrate temperature of 370-420 degrees C at an applied current of 180-200 A to the evaporation boat. Morphology, microstructures, and compositional studies of the grown nanowires were performed by employing field emission scanning electron microscopy (FESEM), X-Ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) respectively. Nanowires were uniformly grown over the entire Si substrate and each of the nanowire is capped with a catalyst particle at their end. X-ray diffraction study reveals the crystalline nature of the grown nanowires. Transmission electron microscopy study on the nanowires further confirmed the single crystalline nature of the nanowires. Energy dispersive X-ray analysis on the nanowires and capped nanoparticle confirmed that Indium act as catalyst for In2O3 nanowires growth. A self catalytic Vapor-Liquid-Solid (VLS) growth mechanism was responsible for the growth of In2O3 nanowires. Effect of oxygen partial pressure variation and variation of applied currents to the evaporation boat on the nanowires growth was systematically studied. These studies concluded that at oxygen partial pressure in the range of 4 x 10(-4), 6 x 10(-4) mbar at applied currents to the evaporation boat of 180-200 A were the best conditions for good nanowires growth. Finally, we observed another mode of VLS growth along with the standard VLS growth mode for In2O3 nanowires similar to the growth mechanism reported for GaAs nanowires.

Electrical Characteristics of Organic Light-emitting Diodes Fabricated by Varying a Hole-size in Evaporation Boat

Electrical characteristics of organic light-emitting diodes were investigated by varying a hole-size in evaporation boat in the device structure of ITO/tris(8-hydroxyquinoline) aluminum/Al. The device was manufactured using a thermal evaporation under a base pressure of Torr. The emitting organics were evaporated to be a thickness of 100 nm at a deposition rate of . A cylindrical-shaped evaporation boat was made out of stainless steel with a small size of hole on top of the boat. Several evaporation boats were made having a different hole size on top; 0.8 mm, 1.0 mm, 1.5 mm, and 3.0 mm. We found that when the hole size on top of the evaporation boat is 1.0 mm, the average roughness is rather smoother compared to the other ones. Also, luminance and external quantum efficiency are superior to the others. Compared to the ones from the devices made with the hole-size of 0.8 mm boat. The luminance and external quantum efficiency of the device made with the hole-size of 1.0 mm boat were improved by a factor of seventy and thirty three, respectively. Also operating voltage is reduced to 2 V.

Optimization of Bi 2Te 3 and Sb 2Te 3 thin films deposited by co-evaporation on polyimide for thermoelectric applications

The optimization of the deposition process of n-type Bismuth Telluride and p-type Antimony Telluride thin films for thermoelectric applications is reported. The films were deposited on a 25 μm-thick flexible polyimide (kapton) substrate by co-evaporation of Bi and Te, for the n-type element, and Sb and Te, for the p-type element. The evaporation rate of each material was monitorized by an oscillating crystal sensor and the power supplied to each evaporation boat was controlled with a PID algorithm in order to achieve a precise user-defined constant evaporation rate. The influence of substrate temperature (in the range 240–300 °C) and evaporation rates of Bi, Te and Sb on the electronic properties of the films was studied and optimized to obtain the highest Seebeck coefficient. The best n-type Bi 2Te 3 films were deposited at 300 °C with a polycrystalline structure, a composition close to stoichiometry, electrical resistivity ∼20 μΩ m and Seebeck coefficient −195 μV/°C. The best p-type Sb 2Te 3 films were deposited at 240 °C, are slightly Te-rich, have electrical resistivity ∼20 μΩ m and Seebeck coefficient +153 μV/°C. These high Seebeck coefficients and low electrical resistivities make these materials suitable for fabrication of Peltier coolers and thermopile devices.

A study of thin films of V 2O 5 containing molybdenum from an evaporation boat

An attempt was made to produce thin films of vanadium oxide by evaporating V 2O 5 in vacuum using molybdenum boats. Following analysis of the films by X-ray photoelectron spectroscopy and Rutherford backscattering spectrometry, it was found that the films contained a large amount of molybdenum (atomic ratio of Mo:V>1). Films were chemically inhomogeneous along the direction of growth such that the value of the atomic ratio decreased from the substrate side of the film to its interface with the air. However, a study of the optical properties of the films revealed that they were optically homogeneous. The films went through a semiconductor-to-metal phase transition at a temperature of approximately 200 °C. When annealed in vacuum at a temperature of 275 °C, it was found that, (a) the films remained amorphous, (b) there was a loss of oxygen leading to an increase in their electrical conductivity, (c) their thickness decreased leading to a larger refractive index of the films, and (d) their band gap energy shifted to a higher photon energy by approximately 0.1 eV.

Naturally formed graded junction for organic light-emitting diodes

In this letter, we report naturally-formed graded junctions (NFGJ) for organic light-emitting diodes (OLEDs). These junctions are fabricated using single thermal evaporation boat loaded with uniformly mixed charge transport and light-emitting materials. Upon heating, materials sublimate sequentially according to their vaporizing temperatures forming the graded junction. Two kinds of graded structures, sharp and shallow graded junctions, can be formed based on the thermal properties of the selected materials. The NFGJ OLEDs have shown excellent performance in both brightness and lifetime compared with heterojunction devices.

The structure and optical properties of silicon ultrafine particles deposited by the gas-evaporation technique with a supersonic jet nozzle

The structure and properties of silicon (Si) ultrafine particles deposited on Si or SiO 2 substrates at 300 K by the gas-evaporation technique with a supersonic jet nozzle were studied. The technique is designed to deposit Si ultrafine particles at the supersonic speed, resulting from the differential pressure between the Si evaporation and the Si deposition chamber. The size of Si ultrafine particles can be controlled with the gas pressure in the evaporation chamber and the distance of the jet nozzle from the Si evaporation boat. The crystallinity and structure of Si ultrafine particles deposited by this technique were studied by the transmission electron microscopy (TEM) and the transmission electron diffraction (TED). With the fixed distance of 5 cm, the size increases from 7 to 10 nm when the pressure of argon gas in the evaporation chamber is increased from 1 to 5 torr. It is found that this technique can fabricate Si ultrafine particles with better uniformity in the size and better crystallinity than the conventional gas-evaporation technique.

Simple evaporation controller for thin-film deposition from a resistively heated boat

A simple, inexpensive circuit is described for switching the current through a resistively heated evaporation boat during thin-film deposition. The circuit uses a silicon-controlled rectifier (SCR) to switch the 0–15-A current in the primary of a 2-kV A step-down transformer that supplies the 0–200-A current to an evaporation boat. The circuit is controlled by a 0–10 V-dc signal similar to that furnished by an Inficon XTC deposition-rate controller. This circuit may be assembled from a handful of parts for a cost of about $400, nearly one-tenth the cost of similar commercial units. Minimum construction is required, since the circuit is built around an off-the-shelf, self-contained SCR unit.

Preparation of indium tin oxide films by vacuum evaporation

High quality indium tin oxide (ITO) films were deposited onto Pyrex glass substrates by vacuum evaporation from an evaporation boat closed by an apertured cover. A film of 6.2 Ω/⦜ sheet resistance and 90% average transmittance in the visible region of the spectrum has been prepared. At a film thickness of 1150 Å the resistivity reached 7.13 × 10 -5 Ω cm. The effect of the deposition parameters on the electrical and optical properties of the films has been studied. We found that (1) the temperature of the evaporation boat strongly influenced the transmittance of the ITO films, (2) the aperture of the evaporation boat also influenced the properties of the films strongly and (3) the oxygen pressure admitted into the chamber should not bee too low. In addition, the effect of the aperture of the boat on the non-stoichiometry in ITO films has been studied by electron spectroscopy for chemical analysis and the impurities in the ITO films have been probed by Auger electron spectroscopy.

UV losses in MgF 2 thin films induced by the evaporation boat

Today there are hardly any products in optical industry which do not employ optical coatings. Mainly in the UV spectral region, laser induced damage thresholds of these coatings are a limiting factor for the development of cost-effective optics. The high power optical components and dielectric coatings have to be developed to cavity optics, beam relay optics, mask imaging optics, and masks. Therefore, we used ultralow loss conventional electron-beam evaporation for Al2O3SiO2 dielectric multilayers. Based on a fundamental coating technique, both multilayer mean background absorption and absorption at localized spikes have been reduced drastically. The resulting KrF laser damage threshold of HR coatings is 16 J cm−2 (1-on-1, 30 ns MSC). Multilayers have been characterized by atomic force microscopy, photothermal microscopy, absorption measurements, and spectroscopy of sputtered neutrals.

Electron impact ionization cross sections of Cu and Au between 40 and 250 eV, and the velocity of evaporated atoms

The total ionization cross sections of Cu and Au were measured with a simple crossed-beam apparatus for bombarding electron energies between 40 and 250 eV. The maximum cross sections were σ (Cu)=(7.6 ± 1.1 × 10−16cm2 at 95 ± 10 eV and σ (Au) =(15.3 ± 2.1) × 10−16cm2 at 100 ± 10 eV. The ratio of the cross sections is σ (Au)/σ (Cu) =2.0 ± 0.2 between 50 and 180 eV. The shape of our cross section curve for Cu compares well with a previous measurement by Crawford. An evaporation model which predicts thermal equilibrium between a liquid and the atoms evaporating into a vacuum is discussed, and the average velocity of atoms evaporated from an evaporation boat is calculated.

Some parameters affecting the resistivity of vapour deposited CdS films

Data are presented on the influence of the evaporation boat material and of a superimposed oxide dielectric film on the resistivity of evaporated CdS films.