Effect of Process Parameters on Powder Quality (original) (raw)
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Generation of small batch high quality metal powder
Powder Metallurgy, 2014
For the development of a small batch metal atomization system, based on free fall atomization (ffa) and close-coupled atomization (cca), different powder quality features were defined to estimate the influence of the process parameters. Copper-tin alloys were used as feed stock material. Particle size distribution, appearance of satellite particles, particle circularity and the flowability were recorded as criteria of particle quality. Using data obtained in these experiments, main process parameters such as atomization pressure, mass melt flow, and height of the spray chamber as well as the atomizer system have been evaluated with respect to powder quality features. The atomization system was optimized to produce high quality powder with narrow particle distributions ( !",! !",! = 1.6 for ffa) and high circularity with mass melt flows in the range of 100 kg/h using melt volume between 100 and 1000 ml.
Influence of particle properties on powder bulk behaviour and processability
International Journal of Pharmaceutics, 2017
Understanding interparticle interactions in powder systems is crucial to pharmaceutical powder processing. Nevertheless, there remains a great challenge in identifying the key factors affecting interparticle interactions. Factors affecting interparticle interactions can be classified in three different broad categories: powder properties, environmental conditions, and powder processing methods and parameters. Although, each of these three categories listed is known to affect interparticle interactions, the challenge remains in developing a mechanistic understanding on how combination of these three categories affect interparticle interactions. This review focuses on the recent advances on understanding the effect of powder properties, particularly particle properties, its effect on interparticle interactions and ultimately on powder bulk behaviour. Furthermore, this review also highlights how particle properties are affected by the particle process route and parameters. Recent advances in developing a particle processing route to prepare particles with desired properties allowing desired interparticle interaction to deliver favoured powder bulk behaviour are also discussed. Perspectives for the development of potential particle processing approaches to control interparticle interaction are presented.
Powder Manufacturing Techniques: A Review
International journal of Research and Review , 2023
The growing need for advanced materials has placed a significant emphasis on the production of top-tier metal powders. To fulfill this demand, several established powder production methods have emerged, aimed at delivering high-purity metal powders. This review paper explores the various techniques used in the production of metal powders, addressing their importance in meeting the evolving requirements of modern manufacturing.
Characterization of NiCu alloy powders produced by the atomization process
Materials Science and Engineering: A, 1991
The atomization techniques is an extensive way for producing rapidly cooled metal powders. This paper presents an experimental study of some process parameters on the powder properties of a 70 wt.% Ni-30 wt.% Cu alloy. The experimental procedures utilized and the experimental results are presented. Water and air were used as atomizing fluids. The atomizing fluid pressure and the melt pouring temperature were also changed. The following powder characteristics were measured: particle shape and particle size distribution, loss of H2, apparent density and flowability, and particle microstructure. The powder characteristics are correlated with the process parameters. As was expected, water promotes a greater cooling rate than air in the atomizer and particle shape changes were also noted. An increase in the melt pouring temperature and fluid pressure changes the particle size distribution with a decrease in the mean particle size.
Journal of Materials Processing Technology, 2006
The production of metal powder using gas atomization technique is a wide spread process for manufacturing a wide range of spherical metal powder alloys. Metal powder properties generally improve with smaller powder particle size. Close-coupled atomizers are of great interest and controlling their performance parameters is critical for metal powder producing industries. In this study a new designed close-coupled nozzle system was used to produce tin powder to investigate the effect of the protrusion length of the melt delivery tube on the pressure formation at the melt tip. Observed improvement in particle refinement cannot be directly attributed to an increase in atomizing pressures and gas kinetics. Results from this study indicated that the observed metal flow rate was not behaving as what was earlier assumed, namely that, deeper aspiration enhanced metal flow rate. The melt flow rate was reduced with increasing the atomizing gas pressure. So that gas to melt mass flow ratio was increased for the same protrusion length and this ratio increase caused the finer powder particle size.
Comparison of grain size distributions obtained by XRD and TEM in milled FCC powders
Nanostructured Materials, 1999
Measurements of grain size in powders of the Cu-15at%Al, Cu-20at%Ni, Cu and Ni systems, milled for different times were conducted. X-ray diffraction (XRD) (Warren-Averbach method) and transmission electron microscopy were used for that purpose. From both techniques, distributions of grain diameter (length) were obtained, which permitted to compare both results. Such results were interpreted by considering previous studies of particle size evolution and microstructural evolution. A better comprehension of phenomena that occur in the mechanical alloying, as the grain refinement and the solid solution formation, is attained. The grain size results obtained by the two techniques were coincident for the Cu-15at%Al system. This system did not present adherence of the powders to the milling media. In the case of the Cu-20at%Ni, Cu and Ni systems, that presented adherence, the results were coincident solely in the powder milled for 864 ks. This is explained due to the microstructural homogenization, reached until that time. The grain size as a function of the milling time of the two classes of FCC systems, being referred to the adherence phenomenon, presented opposed trends. For example, for the Cu-at15at%Al system, the 70% of the population of grains had a grain size smaller than 7.5, 12 and 20 nm for the milling times of 180, 360 and 864 ks respectively. In the case of the Cu-20at%Ni, Cu and Ni systems, the 70% of the population of grains had a grain size smaller than 35, 22 and 16 nm for the milling times of 180, 360 and 864 ks respectively. These contrary trends reflect different mechanisms of grain size refinement. A maximum value of grain size of 20 nm required to form the solid solution in the Cu-at15%Al and Cu-20%atNi systems was found.
Atomization process for metal powder
Materials Science and Engineering: A, 2004
A new atomization process has been developed, which combines pressure and gas atomization. The melt leaves the pressure nozzle as a hollow thin film cone. After the pre-filming step, the melt is atomized by a gas stream delivered by a ring nozzle. The objectives of this investigation are to achieve a narrow size distribution and low specific gas consumption compared to conventional gas atomization techniques. Both lead to a higher efficiency and low costs. Tin and some alloys have been atomized successfully with this technique. The mass median diameters from different experiments are between 20 and 100 m. Sieving analysis of the tin powder shows close particle size distributions.
Powder Technology, 2012
Feed frame is a device used in rotary tablet presses to drive the powders into compression dies. It applies shear forces to the powders as they are stirred around the feed frame chambers. This study focused on understanding the particle attrition, powder properties and the flow property changes of the material processed. The results demonstrated that the impact of the feed frame and die disk on the particle size distribution (PSD) outlet depended on the initial mean particle size, the die size and the powder outlet position. It also impacted the flow properties. The scale-up effect using a feed frame for a high production tablet press shows a significant increment in powder attrition.
2017
Metalurgi serbuk sebagai proses yang memanfaatkan serbuk sebagai bahan baku untuk menghasilkan berbagai macam produk. Serbuk dapat dibuat dari bahan bekas atau baru. Penelitian ini merancang sistem atomisasi udara dari kompresor melalui nozzle, digunakan tipe nozzle closed-couple atomizer/confined yang dibuat dari Stainless Steel SUS 304, celah dapat diatur hingga maksimum 0,3 mm, sudut celah nozzle 45 0 , diameter ukuran melt tube 3 mm. Dalam percobaan digunakan bahan baku timah (Sn) dilebur dengan briket batubara dengan tungku berdiameter 250 mm pada suhu 623 K. Cairan timah mengalir dan dikenai udara bertekanan 0.5, 0.6, dan 0.7 MPa. Produk serbuk dianalisis ukuran partikel dengan Mesh dan Mikroskop Stereo Komputer. Hasil penelitian menunjukan kecendrungan dengan naiknya tekanan dan kecilnya partikel ukuran serbuk, didapatkan ukuran partikel terkecil berdiameter 15,5 µm.