INVENTION OF NEW PROCESS FOR TUNGSTEN CARBIDE COATING ON GUN POD COMPONENTS OF HAWK AIRCRAFT.
This invention relates to the development of new process for tungsten carbide coating on gun pod components of Hawk Aircraft.
Tungsten carbide coatings exhibit excellent wear resistance by virtue of their high hardnesses. These coatings have a high resistance to fretting, corrosion, oxidation and imparts ability to carry high compressive loads at higher temperature levels.
Tungsten carbide to spec LW IN 30 (87%WC & 13%Co) coating processes is done by M/s PRAXAIR, UK through D GUN process. Instead of D Gun process, a new process had been identified i.e. High velocity, oxygen / fuel process (HVOF) for tungsten carbide coating and same had been implemented through M/s Spraymet surface technologies. Bangalore which is a MAKE IN INDIA initiative. HVOF process is better than D-GUN process in terms of Abrasion Mass loss caused to the components.

The following specification particularly describes the nature of invention and the manner in which it is to be performed.
1) BACKGROUND OF INVENTION:
Tungsten Carbide Coating Processes to Spec LW IN 3 0 (87%WC & 13%Co) is used on GUN POD Components of Hawk Aircraft, i.e. Rail Lower Link chute & Rail-Link Chute to impart resistance to wear, abrasion, corrosion and oxidation. The components are being sent to M/s PRAXAIR, UK to carry out the Tungsten carbide coating through 'D GUN processes. This process is now done through High Velocity. Oxygen Fuel (HVOF) combustion driven process. This invention ensures to maintain the Abrasion mass loss (in mg)within limit and in time production of Gun pods of Hawk military aircraft fleet. This new process fulfils 'Make in India * initiative, meeting the in house production with our resource and technology.
2) OBJECTIVE OF INVENTION:
The main objective of the invention is to improve the wear resistance of components by adopting customized process and also to ensure on time production of aircraft Gun Pods. This invention has fetched to achieve considerable foreign exchange savings and broaden the technology base of our country.
3) DETAIL DESCRIPTION OF INVENTION:
The Gun pod components includes Rail Lower link chute and Rail- Link chute. Over the Rail of the components the bullet will be passing with high temperature and with high compressive loads. To with stand the high compressive load, abrasion/wear, corrosion /oxidation and high temperature, tungsten carbide coating is being applied over the rail, through which bullets are loaded. The specification of tungsten carbide coating as per drawing is LW IN 30 <87%WC & 13%Co) with coating thickness of 50 - 76 microns.
The Gun pod components in Fig 1 are being sent to M/s PRAXAIR, UK for tungsten carbide coating through D GUN process. A new process has been identified in lieu of D GUN process, i.e. High velocity oxygen / fuel process (HVOF) to apply tungsten carbide coating over the components. This new process was

subjected over gun pod components at M/s Spraymet surface technologies. Bangalore. This new process is fully devised in customized manner through in house technology. This is yet another milestone in our 'Make in India' initiative. HVOF processes is better than D-GUN process in terms of Abrasion Mass loss (in mg).
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Fig 1 Gun pod components (Rail Lower link chute & Rail- Link chute)
The Gun pod assy with Rail lower link chute & rail link chute are shown in the Fig 2. .
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