Coimbatore scientists develop a better alternative to cast iron for making machine tools.

The better alternative: Epoxy granite

This colorful cuboidal structure represents Epoxy granite, a type of polymer concrete. A polymer concrete is composed of well-graded inorganic chunks held together with resin instead of the water and cement binder typically used in traditional cement concretes. Epoxy granite contains granular particles of granite (the colorful circles) as filler and epoxy resin (grey colored) as binder. This vibrant looking structure has been developed by a team of scientists at Coimbatore’s PSG College of Technology. The work was sanctioned by the Office of PSA.

Chief Executive Officer, NITI Aayog, Shri Amitabh Kant in a letter of appreciation commended this as “a unique example of ‘Make-in-India’ in the capital goods sector of the country, achieved by the academia and the industry” and wished for more such examples to follow in a letter to Dr. K. Prakasan, Principal-In-Charge, PSG College of Technology, Coimbatore. 

Why did the team develop epoxy granite?

Epoxy granite composite material is a good alternative to cast iron when it comes to building machine tool structures; the following characteristics describe why.

• Have better damping characteristics (Damping is important to diminish an undesired effect like is needed of shock absorbers, or acoustics)
• Improves machine tools’ performance with enhanced dynamic stability
• Better thermal stability
• Enhanced productivity, with repeatability
• Improve tool life
• Machine harder materials

Right now, conventional materials like cast iron are used to build modern machine tool structures. Experts who evaluated the product also call it an economically viable option when compared to conventional cast iron structures. Findings from the work done in this project make a significant contribution to the current efforts to develop know-how and technology in precision manufacturing. It will largely benefit the Indian machine tool industry and will be a good import substitute.

Photographs showing examples of precision assembly of machine tools. 
1.    GFEG bed assembled on machine base, 
2.    A CNC (computer-operated) Vertical Machining centre

The development of epoxy granite is a result of a collaboration between scientists at the Department of Mechanical Engineering, PSG College of Technology at Coimbatore and industry partners, Bharat Fritz Werner Limited, Bengaluru and Galaxy Machinery Private Limited, Belgaum. They collaborated for the project titled “Development of Alternate Materials for Improving Dynamic Response and Damping Properties of the Machine Tool Structures (DRDP)” which was completed in February 2020. The team also made a design manual that walks you through the process of development of epoxy granite machine tool structures.
 

(Images courtesy: The images have been taken from a leaflet shared by the PSG College of Technology)