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AREA OF EXPERTISE: Nano, micro, and macro mechanical properties of nanostructured materials. Reinforcing effect of nanofillers in polymers. Structure-property relationships. Multifunctional nanocomposites incorporating graphene, carbon nanotubes, clay, metal oxides and metal nanofillers in polymers.

OLEM provides testing of materials for research and industrial needs at national and international level. The Laboratory has expertise in project participation as a leading partner of several EU Projects and national projects.

OLEM is equipped with advanced equipment for rheology, nano-, micro-, and macro mechanical characterizations, as follows: AR-G2 Rheometer with DMTA (TA Instruments), Nano indenter with inline AFM, and Universal Micro & Macromechanical tester (Bruker-CETR).):

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AR-G2 RHEOMETER & DMTA

(TA Instruments, USA)

Rheology of liquids (wide viscosity range).

Rheology of solids (DMTA in torsion).

Controlled stress, direct strain and controlled rate.

Magnetic thrust bearing technology.

Ultra-low, nano-torque control.

Streaming video & image capture-flow visualization.

Smart Swap system.

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UNIVERSAL MECHANICAL AND TRIBOLOGICAL TESTER, UMT (Bruker-CETR)

NANOINDENTATER (UNMT) with AFM (Ambios Technology) and PRO500 3D PROFILOMETER (Bruker-CETR)

Macromechanical tests by control of either load or displacement: tension; compression; torsion; combined tension and torsion; combined compression and torsion; fatigue at tension; fatigue at compression; fatigue at torsion; creep; relaxation; hysteresis curves; three point bending, etc. Many of the above tests can be done in environmental control chamber: from 20

°C to 150

°C through different temperature regimes.

Micromechanical tests: Micro-Scratch Test (Blade); Micro-Indentation Test (using Vickers and Rockwell indenters); adhesion (at shear, at tension, and at scratch); wear tests (Ball/Pin-on-Disc Wear Test; Ball/Pin-on-Flat Reciprocating Wear Test); determining the critical load of a non-conductive coating on a conducting substrate, etc. Different ways for visualization of the imprints with 2D and 3D profilometer, optical microscopy, etc.

Nanomechanical testing: Nanoindentation in combination with visualization of the imprints with Atomic Force Microscopy (AFM): nanohardness, Young modulus, nanowear, nanofriction,

Nanoscale structure characterization: AFM scanning of the surface structure and phases. Roughness characterization of the surfaces by 2D/3D profilometer.

O L E M O P E N LA BO R ATO R Y on Experimental Micro & Nano Mechanics

Bulgarian Academy of Sciences / Institute of Mechanics Acad. G. Bonchev St., Block 4, 1113 Sofia, Bulgaria

Contacts: Prof. D Sc. Rumiana Kotsilkova , Tel: (+359 2) 979 6462 ; Assoc. Prof. Dr. Evgeni Ivanov, Tel. (+359 2)-979 6481; 02-979-6407

E-mail: kotsilkova@imbm.bas.bg ; http://www.imbm.bas.bg/index.php/en_US/olem

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Rheological testing in broad range of the viscosity: from low viscosity liquids to polymer melts, ceramics, cement pastes, oils, paints, adhesives, bio-medical materials, cosmetics & pharmaceutics, foods…

Dynamic Mechanical Analysis of solid samples (polymers, ceramics, metals).

Peltier Plate UHP ETC EHP Interfacial test DMTA

AR-G2 is the first commercial rheometer with magnetic thrust bearing technology for ultra-low, nano-torque control. The AR-G2 is packed with Smart Swap Geometries, streaming video and image capture software, and camera viewer. It is the most advanced controlled stress, direct strain and controlled rate rheometer available.

SMART SWAP is truly “intelligent” rheometer system, which includes an integrated magnetic cylinder that stores unique geometry information. The information is automatically read and the software is configured with appropriate parameters (type, dimension, material).

SMART SWAP ACCESSORIES available: Peltier Plate (-40 to 200°C); Upper heated plate (UHP, -30 to 150°C); Environmental test chamber (ETC, -160 to 600

oC) with flow visualization; Electrically heated plates (EHP, -70 to 400°C);

Interfacial test (nano-torque; liquid/liquid or gas/liquid phase with distinct rheological properties).

COMMON TESTS:

FLOW CURVE FOR DISPERSIONS FLOW CURVE FOR POLYMERS VISCOELASTIC PROPERTIES STRAIN SWEEP

DYNAMIC MECHANICAL PROPERTIES OF SOLIDS

IN TORSION

TRANSIENT TESTS (CREEP AND STRESS

RELAXATION)

AR-G2 NANO-TORQUE MEASUREMENTS

IN STRESS & STRAIN CONTROL

OSCILLATION STRESS AND SHEAR RATE RAMPS

I. AR-G2 Rheometer with Dynamic Mechanical Analysis TA Instruments

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NANOINDENTER: OLEM possess nanoindenter with maximum force 450 mN and 3 types indenters: Berkovich type indenter, spherical and conical indenters with diameter from 35 to 95 nm. Nanoindentation allows determining of mechanical characteristics like nanohardness, Young modulus, nanowear, nanofriction. In combination with visualization of the imprints with Atomic Force Microscopy and 2D/3D profIlometer at the same time with nanoindentation is achieve scanning of the surface structure and measuring of the roughness of the surface.

BERKOVICH NANOINDENTER CONICAL NANOINDENTER NANOINDENTATION PROFILES NANOSCANNING HEAD

Load vs. penetration depth curves are recorded during the nanoindentation. After that the hardness and the Young modulus are calculated by the Oliver-Pharr method. If the sample is composed of several layers of different materials type and density, the multiple partial unloading tests characterize the hardness, elasticity and thickness of each layer.

NANOMECHANICAL TESTING OF

MULTILAYERED STRUCTURES NANOINDENTATION - MULTIPLE PARTIAL

UNLOADING TESTS 3D AFM PICTURE OF BERKOVICH

INDENTER IMPRINT SCANNING WITH 3D PROFILOMETER OF

NANOINDENTATION IMPRINT

ATOMIC FORCE MICROSCOPY (AFM): Immediately after the nanoindentation the obtained imprint could be visualized by Atomic Force Microscopy. AFM works in non-contact and contact mode and scanning the surface, structure of the surface and phase boarders. The mode type is chosen depending on the material and its roughness. The hardness and reduced modulus are estimated by the Oliver-Pharr method from the unloaded curve and contact area.

AFM SCANNING WITH DIFFERENT RATE AND

TYPE

AFM VIZUALIZATION OF HOLOGRAM IN NON-CONTACT

MODE

AFM VIZUALIZATION IN NON-CONTACT MODE OF

NANOPARTICLES ON GLASS SUBSTRATE

PROFILOMETER PRO500 (scanner 50 – 500 µm). Measurements of: the material roughness before indentation, the scratch size; visualization of the imprints of nano- and microindentations.

ROUGHNESS OF THE SURFACES IMPRINT OF MICRO-SCRATCH TEST IMPRINT FROM VICKERS

MICROINDENTATION

IMPRINT FROM ROCKWELL

MICROINDENTATION

II. Nanoindenter (UNMT) with Atom Force Microscopy (Ambios Technology) and PRO500 3D Profilometer (Bruker- СETR)

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Standard measurements in the load range of 500 mN to 1000 N; Velocity of vertical motion: from 0.9 to 2400 mm/min.

MACROMECHANICAL TESTS :

Testing equipment of UMT-2M for the tests of tension, torsion, tension and torsion, creep,

fatigue, relaxation (left) and three point bending (right)

Thermochamber

Tests of tension, torsion, tension and torsion, fatigue, creep and relaxation: UMT-2M can measure: Yield Strength, Ultimate Strength; Young’s Modulus; Elongation at Ultimate Strength; Toughness; Energy at yield point.

Three Point Bending Test: Maximum Flexural Stress; Flexural Stress at Break; Modulus of Elasticity.

Force-time / strain-time curve

Force-strain curve

Hysteretic curves

Stress-strain curve

MICROMECHANICAL TESTS :

Tribological measurements, Micro-Scratch and Microindentation: UMT-2M tester can measure broad range of tribological characteristics using different standard test and methods applied for: (1) Bulk materials (metals, plastics, ceramics, composites, etc.); (2) Coatings (thin and thick; hard and soft). Visualization of the imprints with optical microscope, and PRO500 3D Profilometer.

Ball/Pin-on-Disc Wear Test (Rotary drive)

Ball/Pin-on-Flat Reciprocating Wear Test

Ball/Pin-on-Flat Reciprocating Wear Test for determining the critical

load of a non-conductive coating on a conducting substrate

The device allows the monitoring during testing of the actual dynamic normal load (Fz), friction force (Fx), friction coefficient (COF), and depth of wear. Optionally, it can measure additional parameters of contact acoustic emission and electrical contact resistance.

In this test the load can be constant

or increased linearly with time.

Micro& Nano Scratch Test Micro-Indentation Test

The setup can provide rotational or reciprocating motions. The load is applied to the sample and can be kept constant or linearly increasing. Friction force, normal load, electric contact resistance and acoustic emission are measured and recorded. Scratch depth, with capacitance are also readily available.

Micro-Indentation tests (depth-sensing and traditional) can be performed using either Rockwell or Vickers indenter, with a capacitance sensor.

III. Universal Macro & Micro Mechanical and Tribological Tester with Thermocamera, UMT-2M (Bruker-CETR)