High speed imaging and Fourier analysis of the melt plume during close coupled gas atomisation

Authors: McCarthy, I.N.1; Adkins, N.J.2; Aslam, Z.1; Mullis, A.M.3; Cochrane, R.F.1

Source: Powder Metallurgy, Volume 52, Number 3, September 2009 , pp. 205-212(8)

Publisher: Maney Publishing

Key:
Free Content - Free Content
New Content - New Content
Subscribed Content - Subscribed Content
Free Trial Content - Free Trial Content

Abstract:

A high speed digital analysis technique has been used to study the atomisation plume of a superheated sample of Ni-Al in a close coupled gas atomiser. The atomisation, incorporating a generic melt nozzle and die design was captured using a Kodak high speed digital analyser at a frame rate of 18 k frames per second. The resulting 65 536 frames were then analysed using a specially designed routine, which calculates values of optical brightness and position of the intensity maximum for all frames and performs Fourier analysis on the sequence. The data produced from this analysis show that the plume, pulses at low frequencies (<25 Hz) and precesses at higher frequencies (∼360 Hz) around the atomiser's centreline. To aid investigation into the origins of this precession and other phenomena it was decided to conduct further experiments using an analogue system. The analogue atomiser reproduces the important features of the full atomiser but instead of atomising molten metal, the analogue system atomises water, providing a quick and easy way of testing the effects of changing parameters. Using this system it was found that the precession of the melt plume is independent of the atomiser's gas inlet pressure but strongly dependent on both the die and melt nozzle's geometry.

Keywords: CLOSE COUPLED GAS ATOMISATION; HIGH FRAME RATE IMAGE CAPTURE; GAS PLUME; ATOMISATION NOZZLE GEOMETRY; FOURIER ANALYSIS; NI-AL

Document Type: Research article

DOI: 10.1179/174329409X409549

Affiliations: 1: Institute for Materials Research, University of Leeds, Leeds LS2 9JT, UK 2: CERAM Research, Queens Road, Penkhull, Stoke-on-Trent ST4 7LQ, UK 3: Institute for Materials Research, University of Leeds, Leeds LS2 9JT, UK;, Email: A.M.Mullis@leeds.ac.uk

The full text electronic article is available for purchase. You will be able to download the full text electronic article after payment.

$51.00 plus tax      Refund Policy

 

OR

Back to top

Key:
Free Content - Free Content
New Content - New Content
Subscribed Content - Subscribed Content
Free Trial Content - Free Trial Content
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages.
Page Help Click here for Page Help
Shopping cart
Tools
Sign in






Need to register?
Sign up here
Text size: A | A | A | A