Facilities

Analytical Instruments available

X-Ray Diffraction System (M/S Bruker AXS Model D8 Advance System)	Inductively coupled Plasma-Atomic Emission Spectroscopy
X-Ray Fluorescence Spectrometer (M/S Philips make PW 2,400 System)

Corrosion Testing Unit

ARCI is developing various coatings on different materials by methods like D-Gun, PVD, CVD, Cold Spray, MAO, Sol-Gel etc and the material properties like wear resistance, dielectric properties, electrical and thermal conductivity are improved. Improvement of corrosion resistance is one of the most important and challenging works done by coatings. As a part of material/coating development we need to understand their corrosion behavior in different types of environments. This study is carried out by field tests and Laboratory tests. The field tests require lot of time and have budget constraints, where as laboratory tests are particularly useful for quality control, material selection, materials and environmental comparisons and the study of corrosion mechanisms. ARCI has procured two such systems where both environmental tests and accelerated tests can be done in the laboratory.

1. Cycling Corrosion Cabinet

MAKE: Atlas Material Testing Solutions, USA
MODEL: CCX 2000

To better understand the potential for adverse effects of outdoor exposure, materials are regularly tested to various environmental conditions. Also, since the real world has many ever-changing conditions, it made sense to test materials to more than one environmental condition. The cyclic corrosion cabinet is now accepted as superior at duplicating actual environments. It improves repeatability, reduces time spent in handling samples and also operator error by creating different environments in one cabinet.

Standard exposure cycles like salt or chemical fog, water fog, salt spry, dry-off cycle, high temperatures i.e. up to 70 ºC can be created for required time from hours to No of days which are closer to environmental changes.

Salient Features

Materials of different sizes and shapes can be tested under various environmental conditions by using various standard methods like ASTM B117, ASTM G85 A5, CCT I, CCT IV, SAE J2334 and GM9540B. Any required method can be programmed.

Samples are exposed to various environments in the chamber, taken out periodically for further testing, characterization and evaluation of corrosion mechanisms.

Cyclic Corrosion Chamber (CCX 2000)

2. Electrochemical Corrosion Testing Equipment

The electrochemical testing system consists of two units.

a. Electrochemical interface B. Impedance/Gain-Phase Analyzer along with softwares Corroware and Z plot

a. Electrochemical Interface (SI1287-Solartron, UK)

The corrosion is an electrochemical process and electrochemical potential is the driving force for reactions. The principle employed in the electrochemical interface is based on the application of a controlled voltage to a sample (working electrode) and measurement of the change in current, or vice versa. The corrosion rates of the specimens can be determined using Corroware programme.

Most of the corrosion type's uniform, localized, galvanic, dealloying; stress corrosion and hydrogen-induced failure can be analyzed by this technique. Conventional electrochemical experiments like static, dynamic polarization, potentiostatic, potentiodynamic experiments etc. can be done.

This system is extensively used to study the corrosion properties of coated substrates, based on the results further improvement of coatings has been done. Different types of coatings like DLC on Al alloys, MAO coatings on Al, Coating on steels and Al alloys by Sol-Gel technique, materials like Mg-Zn, steels, alloys have been analyzed.

The system can also be used to study batteries, fuel cells, inhibitors, electroplating and catalytic properties etc.

b. Impedance/Gain-Phase Analyzer for EIS (SI1260-Solartron, UK)
Frequency range 10 µHz to 32 MHz with 10 µHz resolution

Electrochemical Impedance Spectroscopy is a powerful technique, which can provide lot of information on corrosion reactions, mass and charge transport, the characteristics of material and coating in different electrolytes. An electrode interface undergoing an electrochemical reaction is typically analogous to an electronic circuit consisting of a specific combination of resistors and capacitors. This is used to characterize the electrochemical system in terms of its equivalent circuit.

The system is widely used in characterization of materials, batteries and coatings and to illustrate their corrosion mechanism. It is also used for investigating mechanisms in electro deposition, electrodissolution, passivity and corrosion studies.

ELECTOCHEMICAL CORROSION TESTING EQUIPMENT