Laboratory of Vacuum Heat Treatment and Tribology

Head of laboratory: prof.dr. Bojan Podgornik

e-mail: Bojan.podgornik@imt.si

tel.: +386 1 4701-930

mobile: +386 41 793 146

Metallic materials and technology department

Laboratory for Vacuum Heat Treatment and Tribology conducts fundamental and applied research in the fields of vacuum heat treatment, surface engineering, tribology, and integrity of metallic materials. Its research focuses on understanding the relationships between microstructure, heat and surface treatment processes, and the resulting material properties, as well as on developing solutions to improve the reliability, durability, and service life of tools and high-strength components.

Key activities and services:

• development and optimization of vacuum heat treatment and cryogenic treatment processes;
• tribological investigations of friction, wear, and loadbearing capacity of contact surfaces at room and elevated temperatures;
• fracture toughness testing and investigations of mechanical and thermal fatigue;
• measurement and analysis of residual stress fields;
• development and evaluation of thermochemical treatments, coatings, and combined surface engineering systems;
• expert assessments, failure analysis, and R&D support for industry.

About the laboratory

The Laboratory for Vacuum Heat Treatment and Tribology brings together expertise in material processing, surface modification, tribological testing, and structural integrity assessment. Its activities are aimed at tailoring the performance of metallic materials and components through controlled heat and surface treatments, while establishing the relationships between chemical composition, microstructure, processing parameters, and the resulting mechanical, fatigue, and tribological performance.

Research activities include the development and optimization of vacuum heat treatment of tool steels and other high-performance steels, heat treatment of additively manufactured metallic materials, and investigations into the use of deep cryogenic treatment for improved material performance. In the field of surface engineering, studies are focused on chemo-thermical treatments and their combination with functional and wear-resistant coatings to improve the load-bearing capacity, wear resistance, and service life of contact surfaces, tools, and components. A dedicated research area is the development of surface systems with reduced friction or self-lubricating properties for demanding high-temperature forming processes.

A significant part of the laboratory’s activities is devoted to the investigation of friction and wear, load-bearing capacity of contact surfaces, fracture toughness, residual stresses, and resistance to mechanical and thermal fatigue. Through an integrated approach, we evaluate how microstructure, heat and surface treatment, and loading conditions affect damage initiation, degradation, and the service life of materials and components.

Research is carried out within the Metallic Materials and Technology research programme, through fundamental and applied research projects, and in direct cooperation with industrial partners. The laboratory also provides technical and R&D support, particularly to the tooling and metal-processing industries. Support includes the development of new products and processes, optimization of heat and surface treatments, and solving production- and service-related problems.

Research activities and services

The laboratory’s activities primarily include fundamental and applied research, testing, analysis, and expert and R&D support in the fields of heat treatment, tribology, fracture mechanics, fatigue, and surface engineering.

Heat Treatment and Process Development

• development and optimization of vacuum heat treatment processes for tool and other highstrength steels;
• development and optimization of heat treatment processes for additively manufactured metallic materials;
• effect of heat treatment parameters on microstructure and final material properties;
• development of advanced tempering maps, which, in addition to hardness, include the effects of heat treatment parameters on toughness, bending strength, wear resistance, machinability, and resistance to mechanical and thermal fatigue;
• development and effectiveness of deep cryogenic treatments in metallic materials;
• optimization of combined heat and surface treatment processes.

Tribological Testing and Research

• determination of friction and wear under dry and lubricated sliding contact;
• evaluation of wear resistance of contact surfaces, including the effects of heat treatment, thermochemical treatment, surface modification, coatings;
• loadbearing capacity of contact surfaces at room and elevated temperatures;
• tribological behaviour of materials under contact conditions representative of real industrial applications;
• evaluation of materials formability and protective surface systems;
• assessment of cuttingedge stability and resistance;
• analysis of the effects of microstructure, hardness, toughness, and surface properties on friction, wear, and damage mechanisms.

Mechanical Integrity and Fatigue

• fracture toughness measurement of metallic materials;
• investigations of mechanical and thermal fatigue resistance;
• analysis of the effects of microstructure, heat treatment, and surface condition on crack initiation and propagation;
• evaluation of the relationships between hardness, strength, toughness, wear resistance, and material service life.

Residual Stress

• measurement and analysis of residual stress fields;
• assessment of the effects of heat treatment, machining, surface engineering, and service loading on the development and distribution of residual stresses;
• correlation of residual stress states with fatigue resistance, crack initiation, and dimensional stability of components.

Expert Assessments and Industrial R&D Support

• expert assessments in the fields of heat treatment, tribology, and surface engineering;
• damage and failure analysis of tools and machine components;
• characterization of materials, microstructure, and relevant mechanical and tribological properties;
• solving technological and productionrelated problems;
• optimization of material selection, heat and surface treatment processes, and operating conditions;
• support in the development of new materials, products, and technological processes,
• improving the reliability and service life of industrial components.

Key equipment

• IPSEN VTTC324R horizontal vacuum furnace for heat treatment and sintering

Chamber dimensions: 600 × 900 × 400 mm, maximum load capacity: 400 kg, temperature range: 350–1250 °C, vacuum level: 10⁻⁵ mbar, maximum gas quenching pressure: 5 bar (N₂)

• TAV H2S high-pressure laboratory horizontal vacuum heat treatment furnace

Chamber dimensions: 200 x 300 x 200 mm, max. load capacity: 40 kg, max. operating temperature: 1270°C, vacuum level: 10^-2 mbar, max. gas quenching pressure: 20 bar (N₂), 10 bar (Ar)

• Metaplas plasma nitriding furnace

maks. temperature: 900°C, suitable for nitriding of Al-, Fe- and Ti-Alloys, chamber dimensions: f700x1000 mm, active screen, pulsed plasma operation, Processes: nitriding, nitrocarburizing and oxy-nitriding

• Chamber for deep cryogenic treatment

chamber dimensions: 450x600x500, min. temperature -196°C, Modes: conventional & cycling  

• MTS3000 RESTAN residual stress measurement system

Hole-drilling method (ASTM E837), Depth profiles (up to 2 mm), suitable for on-site/in-situ measurements

• Experimental thermal fatigue test rig

Induction heating, internal water cooling, N₂ protective atmosphere

• LoadScanner ULS4 simulation test rig for load-bearing capacity and galling resistance of contact surfaces

temperature range: 20 – 650°C, dry and lubricated contact, applied load range: 50-5000 N, sliding speed range: 0.001 – 1 m/s

• HTR2 reciprocating sliding tribometer

testing at room temperature, dry and lubricated contact conditions, contact geometry: point, line and area contact, max. load: 1000 N, frequency range: 0,01 – 50 Hz, stroke length range: 1-100 mm

Projects and References

Projects:

1. ARRS-SLO L2-7599 – Applied project; New generation of nano-particles modified creep resistant steels (SIJ Metal Ravne; 2016-2019)
2. RRI-TRL3-6 program MARTINA; MAteRials and Technologies for New Applications; WP Development of new high-strength steels; (2016-2019)
3. M-ERA.Net – HEAMODEL; High entropy alloys with predictable mechanical properties by computational modelling (2017-2020)
4. ARRS-SLO J2-9211 – Basic project; Improving properties of metallic materials through deep cryogenic treatment (2018-2021)
5. COMET – Austrian Research Program; Self-lubricating claddings for high temperature forming of lightweight alloys (2021-2022)
6. Norway Grants - Climate Change Mitigation and Adaptation – CIRCI; Circular Industry – The Application of Circular Economy Principles in Industry Processes (2022-2024)
7. NewSkin Open Innovation Test Bed - Demo-case collaboration; Nano-laser surface modification of CrVN coatings for high-temperature forming applications (2023-2024),
8. ARIS-CEA NC-24004 - Basic project; Understanding H-embrittlement mechanisms in additive manufactured stainless steels (2024-2025) 

Expert Assessments and Industrial Collaboration:

• Armas (Slovenia): Fracture analysis of steels for defenceindustry applications
• DeMartin (Switzerland): Tribological investigation of modified Cr and hybrid DLC coatings
• Hidria Rotomatika (Slovenia): Engineering of active components of fineblanking and stamping tools
• Hilti (Liechtenstein): Tribological characterization of coatings and lubricants for handtool components and anchor bolts
• Impol (Slovenia): Measurement uncertainty assessment; tribological testing of lubricants for foil rolling; analysis of wear mechanisms and damage evolution in blanking tools
• KOVIS (Slovenia): Thermalfatigue resistance of steel castings
• MARSi (Slovenia): Effect of heat treatment on the properties of additively manufactured maraging steel
• Pankl (Austria): Loadbearing capacity of DLC coatings for motorsport applications
• Precision Resources Slovenia: Heat treatment and cryogenic treatment of fineblanking tools
• SIJ Metal Ravne (Slovenia): Development of advanced tempering diagrams for tool steels
• Štore Steel (Slovenia): Development and testing of highstrength spring steels
• UNIOR (Slovenia): Optimization of vacuum heat treatment and surface modification of forging dies

Team

prof.dr. Bojan Podgornik (Head)

dr. Marko Sedlaček

dr. Venu Yarasu

Matevž Mali (young researcher)

Branko Zvonar