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Girish P. Kelkar, Ph.D., C.W.I.

(562) 743-7576

WJM Technologies provides consulting and training services for all your material joining needs including resistance welding, laser welding, TIG/MIG, ultrasonic welding, plastic welding, soldering, metal and ceramic brazing, heat staking, glass tube sealing, etc.

Check out our online training offerings at the Training tab

Subscribe to our quarterly welding newsletter "The Weld Nugget" by sending us an email at

Click on any of the topics below to open the corresponding newsletter:

A Eutectic CompositionResistance BrazingPlumbum - Regular LeadedWelding Ni plated components, Upset Welding, Breaking In, Resistance Welding of Galvanized Steels, Flux Cored Arc Welding, Ain't no fire without a spark, Temperature Control in Resistance Welding, Laser Soldering, Nitrogen Shielding Gas?, Follow-up Force, Laser Welding of Plastics, Resistance Welding Electrode Cooling, Crowning Glory, Resistance Welding, Weld Overlap, Core Values of Welding, Conduction Mode Laser Welding, Etching - The Good Corrosion, Single Failure Mode, Induction Brazing, Ms. Moly B. Denum, Tack Welding, Active Metal Brazing, Manganese - The Cleanup Crew, Stirred - Not Shaken, Plasma Arc WeldingStorm in a Teacup, Keyhole Welding, Scratch and Polish, Trail Mix, Metal Transfer In MIG Welding, Party PoopersTemper Tantrums, MIG Welding, Rustless Steel, Thar She Blows, TIG Welding, Dress for Success, Hocus Focus, Stick with it, Terra Firma, Groove Welding, Arc of Welding, Luke - I am your father, Does Spatter Really Matter?, Tailor Welded Blanks, You say spatter I say splatter, Elemental Attraction, Magnetic Pulse Welding, A Titanic Problem, A Road Less Traveled, Cold Metal Transfer, CCC?, Heat Balance, Underwater Welding, To kill a steel, TRIP Steel, Flash Welding, Nickel for your thoughts, Stressed Out, Thermit Welding, Sulfur - It Stinks, HAZ - Feeling the Heat, Diffusion Welding, Porosity - The Friendly Foe, Dissimilar Metal Welding - Mixing it up, Friction Stir Welding, Oxygen - The Kiss of Death, Solid-State Welding or Bonding, Weldbonding - An Oxymoron, Hyrdrogen - The Little Big Element, Electron Beam Welding, Difference Between Brazing and Soldering, All that soot is not carbon, Cross-sections: The Soul of Weld Analysis, Ultrasonic Welding - The Good Vibrations, Chromium - The "Stainless" in Stainless Steel, Austenite - Mother of All Microstructures, Feedback Control, Berlin Airlift - Welding Saves a City, Anatomy of a Laser Pulse, Hybrid GMAW/Laser Weld, All that glitters is GOLD, Weld Cracks - Engineer's Worst Nightmare, Explosion Welding - Doing it with a bang!, Tungsten - Metal that cried wolf, Definition of good weld, Fiber Lasers, Weld Cracking in Liberty Ships.

WJM Technologies Services

WJM Technologies (Welding and Joining of Materials) provides end-to-end advisory services for all your metal, ceramic, and plastic joining needs.  Our welding consulting services include product evaluation, part design, material selection, process selection, process development, process optimization, and metallurgical analysis.  We deal with all commonly used processes including laser welding, resistance welding, arc welding (TIG, MIG, and plasma), ultrasonic welding, soldering, brazing, plastics welding, glass tube sealing, amongst other processes.  We also provide welding training (classroom and hands-on) for laser welding, resistance welding, arc welding, ultrasonic welding, welding metallurgy, and design of experiments.  Many of our customers use us for failure analysis with a metallurgical evaluation of the welds for cracks, porosities, and other issues.  Give us a call if you have any concerns with your weld or just have a quick question.

Professional Experience

Dr. Kelkar has been involved with metal welding and ceramic joining since 1990 starting with a Ph.D. in ceramic brazing from Penn State University where he investigated brazing of alumina using active metal brazing alloys.  Active brazing alloys contain a small amount of Titanium that is able to reduce the ceramic and form a strong bond.  After graduation, he joined EWI (Edison Welding Institute, Columbus, OH) as a Sr. Research Engineer and acted as a welding consultant specializing in the field of microjoining including laser welding, resistance welding, ultrasonic welding, soldering, and brazing.  Microjoining is a specialized field where the fundamentals are the same as large-scale welding but the issues are unique in terms of material design and handling.  Following the stint at EWI, he worked as the CTO at Miyachi-Unitek and provided technical guidance and leadership for product development.  In 2002 he founded WJM Technologies, a welding consulting firm, to provide welding-related assistance to customers.  Since then he has acted as an independent welding consultant and worked with all types of manufacturing firms including medical, electronics, automotive, aerospace, and industrial.  A list of clients can be seen under the clients tab at the top of the page.  The type of projects include part design, process selection, process optimization, metallurgical analysis, and failure analysis.  In addition to being a welding consultant, he also provides welding training. All classes are conducted at the client's facility; additional details including pdf brochure are available by clicking on the training tab at the top of this page.