2 is the velocity cloud diagram and the velocity vector diagram of the recirculation zone at the bottom of the bypass. Beneath the bottom of the traction tube is an inverted conical recirculation zone with the opposite direction of air flow velocity and inlet air flow. The boundary between the recirculation zone and the high-speed beam is the sonic line. When the current comes into contact with the sonic limit, it pushes and flows downstream. At the end of the recirculation zone there is a stagnation point, the gas velocity is 0, and the Mach disk is approximately 25mm below the stagnation point.
Wavy films turned into spherical drops and component segregation in the gout microdomain were produced. The table shown contains the most common fuels and oxidants used to produce flames for AAS. A mixture of different oxidants and fuels can be used to achieve a specific temperature range. Because the dissociation and decomposition of molecules into atoms is easier with more heat, oxygen is the most common oxidizing agent used in flame atomization. To control the flow of an oxidizing agent and feed a rotimeter, this is a vertically placed conical tube. With the smallest end positioned down, a float located in the tube determines the flow.
In the current work, a series of phase transformations of hypothermic Cu (60.9 wt.%) / Sn drops were analyzed when sprayed with gas under pressure. The results indicated that the microstructures of the powders obtained and their morphologies were very relevant for the size of the drop. According to the phase characteristics analyzed by microstructural boron nitride nozzle observations in combination with transient nucleation theory, powders with dimensions of 10 to 100 μm were divided into three categories, showing morphologies of lotus leaves, islands and rays. The competitive formation of Cu6Sn5 or Cu3Sn was also controlled by drop sizes and a diameter of approximately 45 μm was identified as the threshold size.
There are also researchers who modeled the aerosolization process and then measured and verified the parameters, effectively optimizing the aerosolization process . Microstructure and phase distribution of powders were also extensively analyzed. Using plasma rotary electrode processing, Guo et al. discovered that the main stages of Nb-based alloy powders were Nb sosoloid, β-Nb5Si3 and Nb3Si. During coagulation, a fine laminar eutectic structure was formed in the internal powder. The phase transformation of the hypothermic Ti – 48Al (at.%) falls through gas atomization were also examined and discussed with respect to the α and β primary phases .
However, the super cool temperature of the liquid between the adjacent prominences was lower, so its crystals protruded more slowly. As the temperature continued to decrease, the liquid inner core began to crystallize, and the growth of some prominences hampered each other as the outer layer solidified. The faster cooling rates led to a shorter crystallization time, resulting in an insufficient peritectural response, creating the lotus-like microstructure . Therefore, the crystal path model of the drops was approximately 82 μm and 43 μm a1 – a2 – a3 – c . The proportion of Cu’s composition increased with the distance to the surface of the ε phase, which would have led to a constitutional overload before the solidified interface . Therefore, the growth of dendrites ε required the absorption of the Cu and Sn atoms from the solid / liquid interface.
Hydride generators are generally used for the determination of heavy metals and other elements, including lead, arsenic, tin, selenium, and bismuth. This method is useful for these elements due to the increased detection limit. This type of atomizer should take into account the effects of variations in disk or com diameter and rotation speed, in addition to the properties of the liquid and low flow, for each comparison of average drop size.
In our experiment we obtained the compound Cu6Sn5 at 240 ° C for only 5 minutes and the connection could resist temperatures above 400 ° C. Therefore, These compounds show considerable potential for use in high temperature containers. With the development of powder metallurgy technology, the performance of bulk material has been greatly improved through the extensive use of micro and nanopolypowder synthesization, stimulating the demand for powders in the industrial market . In particular, the development of powder injection molding further opens the extensive application of powders (p. Eg., titanium, aluminum, nickel and steel powder) in the aerospace, shipbuilding, automotive and dust production industries . Studies have also reported that highly filled powders can be used in paper coating processes .
Average particle sizes are typically 30-200 μm for Fe, Ni-Co alloys with the upper limit determined by the large boat sizes required to avoid even larger droplet splashes on the walls. The velocity field of the biphasic liquid gas current field is shown in Fig. 4, the length of the recirculation zone is approximately 16 mm, which is longer than that of the monophasic current field.
This method has been widely used since ~ 1900 to manufacture tin, lead, aluminum, and zinc powder, as well as some copper and copper alloys. It was used in the mid-20th century to process Fe-C alloys, but is now obsolete. As expected, the oxygen content of airborne powders is relatively high, generally between 1000 ppm and 1%. Particle shapes vary from irregular to Al, Zn to spheroidal for copper, gold, and silver. It is worth noting that the flight path of the drops of approximately 43 μm was greater than that of the drops of 63 μm . However, the surface of the drops approximately 43 μm in size showed a lotus-like tissue, while the other showed a fringe-shaped tissue.
