Arc spraying of tungsten powder and its process characteristics


Tungsten powder arc spraying

Arc spraying is a kind of thermal spray process that uses arc as heat source, atomize the melting wire with jet stream and form coating by spraying it on the surface of workpiece with high speed. When spraying, the filamentous metal spraying materials made by tungsten powder are separately sent into two contact tubes of arc pistol evenly and continuously by using the wire feed rolls, in which the contact tubes are respectively connected with the cathode and anode of power source and the two metal wires will insulate to each other before the contact. The two ends of metal wires will melt immediately when arc is formed after the short circuit generated by the mutually contacting between them. By this time, the metal droplets can be formed by atomizing the melting metals with compressed air, which will be sprayed on the surface of workpiece with very high speed and form the metal coating.

Tungsten metal powder arc spraying is a kind of new technology in the thermal spray technology that has been started in recent years, which only uses power source and compressed air instead of oxygen, acetylene and other inflammable gases. It has high security and will not be deformed in the spraying process. Currently, the development application range of this kind of technology is very limited, of which many aspects are waiting to be developed so as to better service the processing industry.

tungsten metal powder

Process characteristics of tungsten powder arc spraying

As tungsten powder arc spraying which uses tungsten powder that has high hardness and big density as raw materials have good quality coating, small deformation workpiece, high production efficiency, high energy utilization rate, good economic benefit, simple operation as well as easy to operate in the field and other obvious advantages, it is widely used in the corrosion resistance, wear resistance, decoration, forming special functional coatings and other fields. Below are the process characteristics of tungsten powder arc spraying:

a. It has long corrosion resistance service life. Due to the high hardness and big density of tungsten powder coating material, it can be used to make high quality coating that is smooth, compact and has high bonding strength by arc spraying, of which the corrosion resistance is incomparable to other corrosion control methods.

b. The localization rate of its equipment and raw material reach to 100 percents and its process is easy to operate. Our country is one of the major tungsten producers, in which the tungsten powder refined and restored by the selected tungsten concentrate will have very high purity, which will largely improve the quality of the products produced by spraying technology, besides, as arc spraying is easy to operate, just one set of its equipment can be used in the corrosion resistance operation of parts that have different shapes and sizes, it is easy to be used in the flow operation.

c. Environmental protection: it uses energy conservation and environment protection spraying materials. The emissions which are generated after spraying all meet the national environmental standards, in which the emissions of waste tungsten can be recovered and processed before reutilization.