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Girish P. Kelkar, Ph.D.

(562) 743-7576


WJM Technologies is a one-stop shop for your material joining consulting, training, and job-shop services.  We provide clients with a complete solution for welding and joining issues for a variety of metal, plastic, glass, and ceramic joining processes listed below:


METALS/ALLOYS                PLASTICS                                       GLASS                       CERAMICS             RELATED SERVICES

Resistance Welding                 Ultrasonic Welding                            Tube Sealing                Ceramic Brazing       Metallurgical Evaluation

Arc Welding                           Hot-Plate Welding                                                                                               Process Development

Laser Welding                        Through-Transmission IR Welding                                                                        Process Optimization

Ultrasonic Welding              



TRAINING CLASSES (conducted at client site)

Resistance Welding

Lasers and Materials Processing

Welding and Metallurgy

Gas Metal Arc Welding

Design of Experiments


Not sure about how to proceed?  How about conducting an investigation of your welds using metallographic evaluation techniques.  If you have any questions about welding or about the services provided by WJM Technologies, please call or e-mail and we will be happy to assist you.  Look forward to working with you.


Girish P. Kelkar, Ph.D.

(562) 743-7576

Mailing Address:

P.O. Box 4018

Cerritos, CA 90703



Recent Publications:

Pulsed Laser Welding (December 2008) (PDF), SOJOM 2008, Tiruchirapalli, India

Bond Formation in Laser and Resistance Welding (September 2007) (HTML text only / PDF), 3rd International Welding Congress, Mexico

Improving Heat Balance in Resistance Welding (September 2007) (HTML text only/ PDF), 3rd International Welding Congress, Mexico

Mode of Least Resistance: Understanding control modes in resistance welding (The Fabrictor August 2007) (link)

Laser Basics: Interactions With Materials (MDDI March 2007) (link)

Resistance and Laser Welding for Medical Devices (MDDI June 2006)  (PDF/link)

DOE for Manufacturing (Westec2004) (HTML text only/ PDF)

Multiple Impulse Resistance Welding (Practical Welding Nov/Dec 2004) (PDF/link)



1.  Laser Weld Monitor (#6670574)

2.  Green Welding Laser (#7088749)


Work Experience:

WJM Technologies (from September 2002)
CTO of Unitek-Miyachi (2000-2002)

Sr. Research Engineer at EWI (1995-1999)



Professional Experience

Has been involved with metal welding and ceramic joining since 1990 starting with Ph.D. 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 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 at Monrovia 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 training for welding including process training, welding for metallurgy, and Design Of Experiments (DOE).  All the classes are conducted at clients facility; additional details including pdf brochure are available by clicking on the training tab at the top of this page.


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