Ceramic coatings for refurbishing machine tool parts

Machine Tool Industry has undergone major developments in providing enhanced service life to spindles, arbors, bearings, etc. Ceramic Coatings by Plasma Spray have been in use in many industries since 1960. Since last decade, this process and ceramic coatings are being used to provide surfaces to seal areas of spindles, contact faces of arbors and electrical and heat insulation to bearings. Apart from OEM level coatings, many user industries are using ceramic coating for refurbishing of spindles and other machine tool parts.

Typical Spray Materials used with Plasma Spray

Metals and its alloys: Steels, Ni alloys, Co alloys, Moy, bronze, copper, Babbit, etc.

Ceramics: Chromium Oxide, Aluminium Oxide, Al Oxide + TiO2, ZrO2, etc.

Carbides: Tungsten carbide, Cromium carbide, TiC

Hardness range of coatings: From SOFT 60Rb (Bronze) to HARD 70 Rc (ungsten carbide)

Benefits of Plasma Sprayed Ceramic over Hard Chrome

Environmental: Less hazardous as there is no Hexavalent chrome involved dust disposal; easier than bath liquid.

Performance: 3-4 Times more wear resistant than Hard-chrome; Micro porosity holds lubrication; Selective area coating is possible; Higher thickness up to 300 microns per side is possible.

Limitations: Ceramics are brittle and are to be handled carefully. The process is not as widely available as hard-chrome.

Spraymet Surface Technologies

Bangalore-based  Spraymet Surface Technologies Pvt. Ltd.,  headed by Mr. P.T. Bindagi, Technical Director and a veteran metallurgist, is engaged in thermal spray, ENP plating and weld surfacing. While their main plant is in Bangalore, the second plant is located in Pune, to stay closer to its customers especially from the automobile sector which is demanding technical excellence, proximity and service all at the same time. Spraymet has the distinction of having pioneered the carbide coatings in the steel mills and galvanizing line roll coating. Spraymet owns a few proprietary coatings like Moly bend (Spraymet MoB) for metal-to-metal wear, and Ductile matrix carbide (Spraymet DMC) for plastic process feed screws. Mr. Bindagi is working towards expanding applications in turbine industry, medical implants, and other frontiers. In his quest to spread knowledge, Mr. Bindagi also picks students from universities for project work related to tribology and wear metallurgy. Spraymet has helped the industry save a lot of money and helped conserve its scarce resources.

– P.K. Balasubbramaniian