TASK 70-31-04-310-501 Micro-plasma Weld Procedure

DMC:V2500-00-70-31-04-00A-627A-D|Issue No:001.00|Issue Date:2013-03-20

Export Control

EAR Export Classification: Not subject to the EAR per 15 C.F.R. Chapter 1, Part 734.3(b)(3), except for the following Service Bulletins which are currently published as EAR Export Classification 9E991: SBE70-0992, SBE72-0483, SBE72-0580, SBE72-0588, SBE72-0640, SBE73-0209, SBE80-0024 and SBE80-0025.

Copyright

© IAE International Aero Engines AG (2001, 2014 - 2021) The information contained in this document is the property of © IAE International Aero Engines AG and may not be copied or used for any purpose other than that for which it is supplied without the express written authority of © IAE International Aero Engines AG. (This does not preclude use by engine and aircraft operators for normal instructional, maintenance or overhaul purposes.).

Applicability

All

Common Information

TASK 70-31-04-310-501 Micro-plasma Weld Procedure

Safety Precautions

General

These general instructions give data on the micro-plasma weld procedure used to repair engine parts. The procedure must only be used when specified in the related Engine Manual and must only be done by fully approved persons.

The micro-plasma weld procedure is better than the argon-arc weld procedure. This is because a lower weld current, with a better local heat input, is used to get smaller weld beads and hot areas.

Theory of the Procedure

The micro-plasma weld is a fusion type weld procedure. A gas which can be argon, helium or nitrogen, goes through an electric arc to make a plasma which then goes through a small diameter nozzle. This effect then tightens the arc to cause a high level of ionization in the plasma gas. When the plasma comes out of the nozzle, the energy in the plasma is released as heat.

Preliminary Requirements

Pre-Conditions

NONE

Support Equipment

NONE

Consumables, Materials and Expendables

NONE

Spares

NONE

Safety Requirements

WARNING

IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURERS MATERIAL SAFETY DATA SHEETS FOR CONSUMABLE MATERIALS INFORMATION SUCH AS, HAZARDOUS INGREDIENTS, PHYSICAL/CHEMICAL CHARACTERISTICS, FIRE, EXPLOSION, REACTIVITY, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE AND CONTROL MEASURES AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

Procedure

    1. Weld Procedure

    1. The micro-plasma weld equipment can only be used with a direct current (DC) output. When an alternating current (AC) output is necessary to weld materials such as aluminum or magnesium, this equipment can not be used.

    2. The micro-plasma weld procedure is only used on engine parts, when a low heat input is necessary. The primary use of the micro-plasma weld procedure is to weld thin metal sheets (That is less than 0.025 in. (0.635 mm) thick), such as thermal blanket skins which are only approximately 0.005 in. (0.127 mm) thick. The procedure can also be used to put small quantities of a filler material on to thin edges, such as turbine blade seal fins.

    3. For weld procedures where currents of more than 12.0 amp are necessary, use the argon-arc weld procedure. The micro-plasma weld procedure is then not recommended.

    4. The gas protection used with this equipment is usually an argon/hydrogen mixture. A mixture with 3 to 5 percent hydrogen is sufficient for most materials. But, when titanium or high chrome steels are to be welded, an argon/helium mixture, or 100 percent argon, must be used. The correct gas to be used will always be specified in the related Engine Manual.

    5. The filler wire to be used is specified in TASK 70-31-02-310-501. Also, because of the low current used for this procedure, do not use filler wire that is larger than 20 imperial S.W.G.

    6. For more general instructions on the micro-plasma weld procedure, refer to TASK 70-31-02-310-501.

Requirements After Job Completion

Follow-On Conditions

NONE