An experimental investigation on accuracy of Hausner Ratio and Carr Index of powders in additive manufacturing processes

Kaleem, Muhammad; Alam, Muhammad Zubair; Khan, Mushtaq; Jaffery, Syed Husain Imran; Rashid, Badar

doi:10.1016/j.mprp.2020.06.061

Cited by 37 publications

(26 citation statements)

References 19 publications

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“…e scanning electron microscope (SEM) samples examined the morphology change of the master alloy and ensured the distribution of reinforcement in the matrix. e powder flow characteristics study was performed based on apparent density: ASTM B 212, tapped density: ASTM B 527 [22], static angle of repose: ASTM B213 [23], Hausner's Ratio: ASTM D7481-09, and Carr Index: ASTM D6393-14 [24].…”

Section: Methodsmentioning

confidence: 99%

Influence of Planetary Ball Mill Parameters on Powder Flowability of AlSi10Mg with Niobium Carbide Using Central Composite Design (CCD)

Mohan

Venkatraman

Raghuraman

et al. 2022

Advances in Materials Science and Engineering

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The hypoeutectic aluminum alloy (AlSi10Mg) is a well-known candidate material used predominantly for its processability and inherent characteristics in metal-based additive manufacturing. Besides, transition metal carbide, such as niobium carbide (NbC), is added to the AlSi10Mg, enhancing its mechanical properties and preferably its wear resistance to the matrix. However, in additive manufacturing, the mixed powder’s flowability is a prerequisite for determining the final properties of the specimens. In this study, mixed powder flowability analysis was carried out through the regular mixing of AlSi10Mg with a varying weight percentage of NbC conducted in the planetary ball mill with different time, speed, and NbC composition following the Central Composite Design (CCD), with a total of 20 experiments. Here, regular mixing was preferred to retain the morphology of the AlSi10Mg (spherical shape) instead of ball milling, which contributes to the degradation of the powder’s shape and size. Finally, based on the combined analysis of apparent density (AD), tapped density (TD), and static angle of repose (SAoR), the flowability characteristics of the mixed powders (AlSi10Mg + X % NbC) were evaluated. The optimum combination (AlSi10Mg + X% NbC) was attained based on the composite desirability criteria.

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Section: Methodsmentioning

confidence: 99%

Influence of Planetary Ball Mill Parameters on Powder Flowability of AlSi10Mg with Niobium Carbide Using Central Composite Design (CCD)

Mohan

Venkatraman

Raghuraman

et al. 2022

Advances in Materials Science and Engineering

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“…The flow is termed excellent/good if the HR was less than 18 and the CI was less than 15. 27 HR, and CI values for mixed powders of AlSi10Mg and NbC are shown in Figure 4(b) and (c). The mixed powder flow was excellent for pure AlSi10Mg due to its spherical morphology.…”

Section: Flow Properties Analysismentioning

confidence: 99%

Experimental investigation on powder processing and its flow properties of AlSi10Mg alloy with niobium carbide for additive manufacturing

Mohan

Venkatraman

Raghuraman

2021

Proceedings of the Institution of Mechanical Engineers, Part E:

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In this study, aluminium-silicon alloy AlSi10Mg powder of spherical morphology was mixed with niobium carbide powder had irregular morphology in weight percentages of 2, 4, 6 and 8 and processed in a planetary ball mill apparatus. The optimal conditions for powder processing were a mixing time of 1.95 h and a speed of 71 RPM without milling balls. The use of milling balls was avoided to maintain the morphology of AlSi10Mg from degradation and improve the flowability of composite powder. To evaluate the flowability of processed powders, flow properties such as apparent density, tapped density, Hausner’s ratio, Carr index, static angle of repose and Hall flow rate were determined. Selective laser melting was used to fabricate AlSi10Mg composite specimens with varying percentages of niobium carbide. Finally, at 6% niobium carbide, the selective laser melting cube specimen had a maximum relative density of 99.21%.

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“…Another influential powder parameter is the density which can be described with the material density as well as bulk density (also called apparent density) and tapped density. The quotient between tapped density and bulk density is called the Hausner ratio and is an indicator for the flowability of the powder [12]. The flowability is also influenced by the shape of the respective particles and the moisture content of the powder and humidity levels [13].…”

Section: Powder Parametersmentioning

confidence: 99%

“…The bulk density was determined at 4.6 g/cm 3 and the tapped density at 5.1 g/cm 3 which led to an Hausner ratio of around 1.11. This indicated a flowability directly between "excellent" and "good" with a "very free" to "free flow" [12]. The flowability was also checked visually and was assessed to be good without significant formation of clusters.…”

Section: Powder Parametersmentioning

confidence: 99%

In situ measurement and closed-loop control for powder supply processes

Breese

Hauser

Regulin

et al. 2021

Int J Adv Manuf Technol

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The powder mass flow rate is one of the main parameters regarding the geometrical precision of built components in the additive manufacturing process of laser metal deposition. However, its accuracy, constancy, and repeatability over the course of the running process is not given. Reasons among others are the performance of the powder conveyors, the complex nature of the powder behavior, and the resulting issues with existing closed-loop control approaches. Additionally, a direct in situ measurement of the powder mass flow rate is only possible with intrusive methods. This publication introduces a novel approach to measure the current powder mass flow rate at a frequency of 125 Hz. The volumetric powder flow evaluation given by a simple optical sensor concept was transferred to a mass flow rate through mathematical dependencies. They were found experimentally for a nickel-based powder (Inconel 625) and are valid for a wide range of mass flow rates. With this, the dynamic behavior of a vibration powder feeder was investigated and a memory effect dependent on previous powder feeder speeds was discovered. Next, a closed-loop control with the received sensor signal was implemented. The concept as a whole gives a repeatable and accurate powder mass flow rate while being universally retrofittable and applicable. In a final step, the improved dynamic and steady performance of the powder mass flow rate with closed-loop control was validated. It showed a reduction of mean relative errors for step responses of up to 81% compared to the uncontrolled cases.

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An experimental investigation on accuracy of Hausner Ratio and Carr Index of powders in additive manufacturing processes

Cited by 37 publications

References 19 publications

Influence of Planetary Ball Mill Parameters on Powder Flowability of AlSi10Mg with Niobium Carbide Using Central Composite Design (CCD)

Influence of Planetary Ball Mill Parameters on Powder Flowability of AlSi10Mg with Niobium Carbide Using Central Composite Design (CCD)

Experimental investigation on powder processing and its flow properties of AlSi10Mg alloy with niobium carbide for additive manufacturing

In situ measurement and closed-loop control for powder supply processes

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