Diagnostic Development for Control of Wire-Arc Spraying

1997 ◽  
Author(s):  
J. Sheard ◽  
J. Heberlein ◽  
K. Stelson ◽  
E. Pfender
Keyword(s):  
Molten Metal ◽  
High Speed ◽  
Metal Droplet ◽  
Arc Spraying ◽  
Voltage Fluctuations ◽  
Arc Voltage ◽  
Spray Process ◽  
Arc Spray ◽  
Labview Software ◽  
The Wire

Abstract This research has focused on characterization of the wire arc spray process with the goal of achieving improved process controls. Arc voltage and current traces have been analyzed on-line using an oscilloscope and a personal computer with LabView software. The characteristic features of the arc voltage fluctuations are correlated with the molten metal droplet formation process using a high speed Laser Strobe video system operating in synchronization with the oscilloscope trigger. Voltage minima occur when larger globules of molten metal leave the wire tip. Analysis of the voltage fluctuations indicate that they are neither random nor periodic, and that they can be described based on chaos theory. This approach may be used for achieving a further understanding of the dynamic nature of the process, and for the development of control algorithms.

Investigations of Arc Behavior and Particle Formation in the Wire Arc Spray Process Using High Speed Photography

2000 ◽  
Author(s):  
N.A. Hussary ◽  
J. Heberlein
Keyword(s):  
Thermal Spray ◽  
High Speed ◽  
Imaging System ◽  
Metal Droplet ◽  
Droplet Formation ◽  
Operating Conditions ◽  
Arc Spraying ◽  
High Speed Photography ◽  
Spray Process ◽  
The Wire

Abstract The wire arc spraying process, one of several thermal spray processes, gained a sizable part of the thermal spray market, however, more control is needed for this process to be used for high precision coatings. This study is aimed at investigating the liquid metal droplet formation process in order to identify methods for droplet trajectory control. A high speed Kodak imaging system has been used to observe the droplet formation for different operating conditions. Decreasing the upstream pressure and the current levels lead to the reduction in the asymmetric melting of both anode and cathode. By decreasing the interactions of the large eddy structures with the formed metal agglomerates one can achieve better control of the particle trajectories and jet divergence. Thus, coatings can be obtained with higher definition and improved reliability.

Study on the Arc Shape in the Wire Arc Spray Process

2010 ◽  
Vol 154-155 ◽  
pp. 109-112
Author(s):  
Jia Ying Zhang ◽  
Bin Shi Xu
Keyword(s):  
High Speed ◽  
Short Circuit ◽  
Digital Camera ◽  
Wire Arc Spray ◽  
Properties Of Coatings ◽  
Spray Process ◽  
Arc Spray ◽  
Arc Shape ◽  
The Wire ◽  
Metal Wires

Being the heat source of arc spray, the characteristics of arc are of importance for properties of coatings. In this paper, the arc shape in the wire arc spray process was analyzed in the aid of high-speed digital camera. It is testified that the arc has the elliptical shape. This type of shape is favorable for heating the metal particles. The arc isn’t always in burning state and it is extinguished frequently. There are two kinds of reasons for arc extinguish. The first one is that the two metal wires short circuit. The second one is that the imperfect melted metal stretches the arc long, and then this part melted and broken away from the metal wires’ tips. If we can control the metal wires state, the properties of coatings will be improved.

Charged Molten Metal Droplet Deposition as a Direct Write Technology

2000 ◽  
Vol 624 ◽  
Author(s):  
M. Orme ◽  
J. Courter ◽  
Q. Liu ◽  
J. Zhu ◽  
R. Smith
Keyword(s):  
Molten Metal ◽  
High Speed ◽  
Droplet Diameter ◽  
Metal Droplet ◽  
Circuit Board ◽  
Charged Droplet ◽  
Direct Write ◽  
Direct Writing ◽  
Drop On Demand ◽  
Metal Droplets

ABSTRACTThe formation of highly uniform charged molten metal droplets from capillary stream breakup has recently attracted significant industrial and academic interest for applications requiring high-speed and high-precision deposition of molten metal droplets such as direct write technologies. Exploitation of the high droplet production rates intrinsic to the phenomenon of capillary stream break-up and the unparalleled uniformity of droplet sizes and speeds attained with proper applied forcing to the capillary stream make many new applications related to the manufacture of electronic packages, circuit board printing and rapid prototyping of structural components feasible. Recent research results have increased the stream stability with novel acoustic excitation methods and enable ultra-precise charged droplet deflection. Unlike other modes of droplet generation such as Drop-on-Demand, droplets can be generated at rates typically on the order of 10,000 to 20,000 droplets per second (depending on droplet diameter and stream speed) and can be electrostatically charged and deflected onto a substrate with a measured accuracy of ±12.5 µm. Droplets are charged on a drop-to-drop basis, enabling the direct writing of fine details at high speed. New results are presented in which fine detailed patterns are “printed” with individual molten metal solder balls, and issues relevant to the attainment of high quality printed artifacts are investigated.

Benefits and Technology Developed to Arc Spray 3/16 Inch (4.8mm) Diameter Wires Used for Corrosion Protection of Steel

2000 ◽  
Author(s):  
F.S. Rogers
Keyword(s):  
Corrosion Protection ◽  
Equipment Design ◽  
Arc Spraying ◽  
Wire Arc Spray ◽  
Spray Process ◽  
Arc Spray ◽  
The Common ◽  
Spray Rate

Abstract It has been generally accepted that amperage and voltage are the only variables used to determine spray rate with the twin wire arc spray process. This belief has led to the common practice of defining spray rates in terms of kgs (pounds) per amperes. The "pounds to amperes" theory has been disproved with die advent of equipment capable of successfully arc spraying 4.8 mm (3/16 inch) diameter wires of zinc, aluminum, or 85/15 (zinc/aluminum). Changes in equipment design, that allowed the use of the larger diameter wires, resulted in the issue of a U.S. patent for arc spraying wires over 3.2 mm (1/8 inch) diameter. To achieve production capabilities for spraying 4.8 mm (3/16 inch) diameter wire, numerous problems needed to be solved, which led to additional patent claims.

Sign in / Sign up

Export Citation Format

Share Document