Glebe Associates provides key service support for micro joining applications using resistance welding, a thermo-electric process for parts that need to be joined at a precisely controlled time and pressure, and (TIG) micro arc welding which is ideal for the high-speed manufacture of coil-based products.
Micro-resistance welding techniques
Opposed electrode welding – The product being welded is placed between two opposed electrodes using either a moving or fixed lower electrode. The upper electrode applies a controlled pressure which triggers the welding current pulse through the joint.
Parallel gap welding – Both electrodes are placed on the same surface of the product and the weld takes using the flow of current between the two electrodes. The electrodes cane be individually mounted with an adjustable gap or alternatively be a bonded pair with fixed gap.
Step electrode – This is similar to parallel gap welding but uses one electrode placed on the bulk of the product and the second electrode placed on the item being welded to it. Both electrodes are independently sprung to ensure good electrical contact.
Primary components for micro-resistance welding
Welding power supply – This can be one of a number of variants – High Frequency DC (HFDC), Linear DC, Capacitor Discharge (CD) and AC. The correct choice depends on the application although our preferred option is a closed loop unit either Linear DC or HFDC.
Weld Heads – These can range from manual products to full servo drive units. The weld head is a key component as it is critical to provide a controlled welding force which is maintained during the material melting which takes place during the welding process. Typical types of weld head are opposed manual or pneumatic, servo drive heads, parallel gap heads and constant force heads for low force applications.
Micro arc welding
This is a process using a non-consumable Tungsten electrode. It is sometimes referred to as the Tungsten Inert Gas (TIG) process. The key components are the power supply, welding head, cables and gas control if required.
Power supply – This provides the welding power together with the high voltage arc start energy. Units can be of closed loop design providing precision control of the output or alternatively capacitor discharge. For low volume applications touch start can be used.
Welding Head – The welding head is primarily designed to hold the electrode accurately and provide a gas or air shield together with any required extraction. Accurate electrode positioning is important to ensure consistent welding results.
Cables – As high voltage arc starting is generally used the cables must be suitably insulated and positioned to avoid causing any electrical interference to any adjacent equipment.
Gas control – Where gas or air shielding is used the flow rates must be carefully controlled to ensure consistent performance. Flowmeters should be used for this.
Process optimisation for existing applications
We can assist in optimising the welding process for applications which are in production or about to go into production. Many organisations cannot justify the cost of a full-time welding application engineer. We offer this service on an ‘as required’ basis which provides an economical long-term solution.
Assistance in product design to ensure suitability for micro-joining
Many companies design products but do not always have the necessary in-house knowledge to make them suitable for the welding process. We can help at this critical phase to ensure the design is correct to minimise future problems in production. Sometimes a minor change to the geometry of the product can lead to significant improvements in welding performance.
Support to automation providers for the integration of welding equipment into automated production lines
Correct integration of the welding equipment is vital to maximise product yield during production. We can support integrators to ensure the micro-welding equipment is installed accurately and also help on aspects such as component jigging and handling to ensure correct presentation. The transition from a manual process to automation is not always as easy as it might appear and can lead to many issues. Our years of experience in this field will provide valuable assistance.
Process and equipment selection for new applications
Sometimes it is not always clear which process or equipment selection is best for a micro-joining application, we can help review and advise from the technical and economic aspects.
Troubleshooting for ongoing application issues
Over time the welding process reliability can drift due to product changes, material changes or other external influences. We can review and help ensure yield is maximised.
This is offered to staff at all levels and will include equipment set-up, process optimisation, troubleshooting, process monitoring. This is particularly important for many companies who do not have the required level of in-house expertise to provide the required process support.
This is a frequently misunderstood area of micro-welding. Monitoring packages are frequently sold on the basis of providing good weld/bad weld information. Whilst general purpose monitors can help we find they are seldom set up to provide accurate weld information, or do not monitor the key parameters. A detailed process analysis is initially required to determine the key process parameters to check prior to even choosing a suitable monitoring package. We can assist in determining the suitability of monitors and train staff in their correct use.
Glebe Associates Ltd
+44 1638 560804
Associated company website:
Wireworks – Bernie Wire