High-End Ther­mo­graphy for Optimal Control of Laser Applic­a­tions

Laser applications are of vital importance in today's industry, science and medicine, because the properties of laser radiation result in numerous different applications.

InfraTec thermography for Laser usage, picture credit: © iStock.com / kynny

Among other things, laser radiation is used in metrology for high-precision non-contact measurement of distances, material thicknesses or surface profiles. Furthermore, they also perform well in spectroscopy, for example in the analysis of chemical compounds. Medical technology takes advantage of the benefits of laser radiation and uses it in areas such as ophthalmology or in the removal of tumours. We also get in contact with laser technology in numerous everyday devices: when scanning bar codes at the counter, at the laser printer in the office or in speed measurement in road traffic.

Lasers in Industry

Due to their numerous positive characteristics, lasers have been used in industry for many years, mainly in material processing. In production engineering for example, they replace other tools and enable the precise processing of a wide range of materials. Lasers perform processes such as cutting, welding and ablating metal, plastic or glass as well as various composite materials and are also used in additive manufacturing. They support the application of protective coatings and carry out heat treatments for hardening, drying and softening. The advantages are clear: lasers themselves are not subject to wear and tear, they do not need to be replaced and can be flexibly adjusted to allow accurate and gentle processing of different materials.

Among numerous industrial lasers, there are those that involve the application of thermal energy for material processing. This is where permanent monitoring and control of the heat development play an important role in order to process materials in accordance with their properties and thus comply with quality and safety standards.

Event On Demand

Optimising Additive Manufacturing Technologies Using Thermography

  • Additive manufacturing: definition, benefits, types, presence and future

  • Fields of application for thermography in additive manufacturing

  • Challenges in additive manufacturing of metals

  • Use of thermography to improve manufacturing technologies

  • Technical requirements for IR cameras in additive manufacturing

Request Recording

InfraTec Webinar: Optimising Additive Manufacturing Technologies Using Thermography - Picture credits: © iStock.com / nordroden

High-end Ther­mo­graphy for Heat-Gener­ating Laser Applic­a­tions in Material Processing

Thermography enables the non-contact visualisation and analysis of the heat flow in the respective measurement and test objects or components. The temperature measurement on their surface allows the energy input of the laser to be controlled and thus ensures that the object to be processed is heated optimally.

Advantages of Process Control with Thermography:
  • Non-contact and non-reactive temperature measurement

  • Mapping of heat flows in components to gain a complete understanding of the process

  • Control of precisely adjusted energy input and reduction of thermal load, due to high measurement accuracy

  • Exact calculation of the final energy input by laser into the component due to complete geometrical and temporal recording of temperature distributions in highly dynamic processes

  • Optimum positioning of non-visible lasers (UV laser, IR laser)

  • Reliable monitoring of heating and cooling processes of materials

Results:
  • Early detection of errors in production, active avoidance of rejects and minimisation of returns

  • Optimisation of process and cycle times as well as pre- and post-processing

  • Non-destructive testing of laser welded joints

  • Direct laser control based on the observed object temperature in real time

  • Derivation of correlations between process parameters and (melting) temperatures

WELD-CHECK by InfraTec

Infrared cameras for the investigation of laser applications have to meet very specific requirements. This applies for example with regard to the temporal resolution: it is characteristic for working with a laser to have short laser action times, where heat input takes place within fractions of a second. This requires measurements with high image frequencies in full and partial images. Especially in micro material processing with pulsed laser light, the demands on thermography systems – such as the ImageIR® 8300 hs – are very high because the processes run at high speed.

The thermal and geometric resolution of infrared cameras is equally important. Depending on the process and material, lasers can be used to generate very large and small temperature differences, which must be monitored precisely and continuously. Here InfraTec offers different functions of the cameras, such as HighSense-modeHDR-function, binning mode and geometric resolutions in the HD range.

Often it is necessary to monitor very precisely – even on fine structures or locally – which input of thermal energy is induced and what the processing temperatures of all materials involved in the process are. Consequently, the combination of geometric and thermal resolution of the camera determines the success of the respective application.

Advant­ages of this Ther­mo­graphy Solu­tions in this Applic­a­tion

Thermography with ImageIR series - HDR feature - Picture credits: © iStock.com / Vershinin M

HDR – Simultaneous Mapping of Wide Temperature Ranges

The High Dynamic Range (HDR) function of the Infrared ImageIR® camera series enables measurement scenarios with extremely different temperatures to be recorded continuously. When recording in HDR mode, multiple thermograms with different integration times and different filters are recorded quickly in succession and compiled into an overall image with a high dynamic range. The measuring range can span up to 1,500 K. Users obtain high-contrast images in a wide temperature range characterized by high measurement accuracy.

InfraTec thermography - High-speed Mode

High-speed Mode – Increase Frame Rate and Sens­it­ivity

Due to the binning technology, infrared cameras have two speed modes – the standard mode and the high-speed mode, in which the frame rate increases more than three times. The field of view remains constant in both modes, so the scene captured by the camera does not change. In high-speed mode, the thermal resolution also increases by a factor of two.

HighSense for thermographic camera series ImageIR®

High­Sense – Always the Optimal Camera Setting

Thanks to HighSense, ImageIR® users have the option of setting up individual measuring ranges based on the factory calibration that best suit the respective task. Depending on the measuring task, the required temperature range can be selected and the optimum integration time for this purpose is calculated – or one decides to proceed in reverse order. Thus, the calibration can be retained even in the case of changed integration times.

Thermografie-Kameraserie ImageIR® mit neuer 10 GigE-Schnittstelle

10 GigE Inter­face for a Strong Increase in Output

The 10 Gigabit Ethernet interface of the high-end camera series ImageIR® opens this extremely fast transmission standard with a NIC specially developed by InfraTec. This works with optical or electrical transceiver modules that are easy to change and are called SFP+.

Integ­rated Trigger / Process Inter­face and Inter­faces – Digit­ally Controlling of a Infrared Camera and External Devices

The internal trigger interface guarantees highly precise, repeatable triggering. Each of the two configurable digital inputs and outputs are used to control the camera or to generate digital control signals for external devices. In this way, for example, the operation of a printed circuit board and the interval of a measurement can be synchronised.

The selection of different camera interfaces allows the processing of analog data, such as the voltage directly through the camera and thus the insertion of this information into the thermal image data. Relevant variables can be included in the evaluations with the software, which makes it easier to draw conclusions about the causes of temperature changes.

InfraTec glossary - Rotating filter- und aperture wheel

Separate Filter & Aper­ture Wheel – Spec­tral Ther­mo­graphy

The combination of a separate filter and aperture wheel, allowing a total of 35 freely selectable combinations, is prerequisite for an universal application in measurement tasks with high object temperatures and in the field of spectral thermography. The neutral density filters used for signal attenuation or the combination of spectral filters and apertures reliably prevent interference effects.

Thermal image during ignition of an airbag  Image Small

Window Mode (Subwin­dowing) – Capture of Rapid Sequences

The thermal imaging camera can be operated in full, half, quarter and sub mode. With the camera control software, it is possible to use the extended subwindowing function. Using click-and-drag, freely definable sections can be set up quickly and conveniently. A defined sub-frame of the detector is picked out to achieve these extremely high refresh rates.

Thermography with ImageIR series - HDR feature - Picture credits: © iStock.com / Vershinin M

HDR – Simultaneous Mapping of Wide Temperature Ranges

The High Dynamic Range (HDR) function of the Infrared ImageIR® camera series enables measurement scenarios with extremely different temperatures to be recorded continuously. When recording in HDR mode, multiple thermograms with different integration times and different filters are recorded quickly in succession and compiled into an overall image with a high dynamic range. The measuring range can span up to 1,500 K. Users obtain high-contrast images in a wide temperature range characterized by high measurement accuracy.

InfraTec thermography - High-speed Mode

High-speed Mode – Increase Frame Rate and Sens­it­ivity

Due to the binning technology, infrared cameras have two speed modes – the standard mode and the high-speed mode, in which the frame rate increases more than three times. The field of view remains constant in both modes, so the scene captured by the camera does not change. In high-speed mode, the thermal resolution also increases by a factor of two.

HighSense for thermographic camera series ImageIR®

High­Sense – Always the Optimal Camera Setting

Thanks to HighSense, ImageIR® users have the option of setting up individual measuring ranges based on the factory calibration that best suit the respective task. Depending on the measuring task, the required temperature range can be selected and the optimum integration time for this purpose is calculated – or one decides to proceed in reverse order. Thus, the calibration can be retained even in the case of changed integration times.

Thermografie-Kameraserie ImageIR® mit neuer 10 GigE-Schnittstelle

10 GigE Inter­face for a Strong Increase in Output

The 10 Gigabit Ethernet interface of the high-end camera series ImageIR® opens this extremely fast transmission standard with a NIC specially developed by InfraTec. This works with optical or electrical transceiver modules that are easy to change and are called SFP+.

Integ­rated Trigger / Process Inter­face and Inter­faces – Digit­ally Controlling of a Infrared Camera and External Devices

The internal trigger interface guarantees highly precise, repeatable triggering. Each of the two configurable digital inputs and outputs are used to control the camera or to generate digital control signals for external devices. In this way, for example, the operation of a printed circuit board and the interval of a measurement can be synchronised.

The selection of different camera interfaces allows the processing of analog data, such as the voltage directly through the camera and thus the insertion of this information into the thermal image data. Relevant variables can be included in the evaluations with the software, which makes it easier to draw conclusions about the causes of temperature changes.

InfraTec glossary - Rotating filter- und aperture wheel

Separate Filter & Aper­ture Wheel – Spec­tral Ther­mo­graphy

The combination of a separate filter and aperture wheel, allowing a total of 35 freely selectable combinations, is prerequisite for an universal application in measurement tasks with high object temperatures and in the field of spectral thermography. The neutral density filters used for signal attenuation or the combination of spectral filters and apertures reliably prevent interference effects.

Thermal image during ignition of an airbag  Image Small

Window Mode (Subwin­dowing) – Capture of Rapid Sequences

The thermal imaging camera can be operated in full, half, quarter and sub mode. With the camera control software, it is possible to use the extended subwindowing function. Using click-and-drag, freely definable sections can be set up quickly and conveniently. A defined sub-frame of the detector is picked out to achieve these extremely high refresh rates.

Asso­ci­ated Ther­mo­graphic Auto­ma­tion Solu­tions

Contact to thermography division of InfraTec

Would You Like to Know More?

It is not unusual for tasks to be associated with special requirements. Discuss your specific application needs with our specialists, receive further technical information or learn more about our additional services.

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Infrared Cameras for Laser Material Processing

InfraTec Infrared camera
Zoom Cameras

ImageIR® 6300 Z

Image Format(640 x 512) IR-Pixel
Detector typeXBn

InfraTec Infrared camera
High-end Cameras

ImageIR® 8300 hs

Image Format(640 x 512) IR-Pixel
Detector typeT2SLS or InSb

InfraTec Infrared camera
System Cameras

VarioCAM® HD head 900

Image Format(2,048 x 1,536) IR-Pixel
Detector typeUncooled Microbolometer Focal Plane Array

InfraTec Infrared camera
Compact Cameras

PIR uc 605

Image Format(640 x 480) IR-Pixel
Detector typeUncooled Microbolometer Focal Plane Array

InfraTec Infrared camera
System Cameras

VarioCAM® HDx head S

Image Format(640 x 480) IR-Pixel
Detector typeUncooled Microbolometer Focal Plane Array

InfraTec Infrared camera
System Cameras

VarioCAM® HDx head 600

Image Format(640 x 480) IR-Pixel
Detector typeUncooled Microbolometer Focal Plane Array

InfraTec Infrared camera
System Cameras

VarioCAM® HD head 800

Image Format(1,024 x 768) IR-Pixel
Detector typeUncooled Microbolometer Focal Plane Array

Laser Sintering

In laser sintering – also known as Selective Laser Sintering (SLS) – granulate is heated by supplying thermal energy to temperatures just above the melting point and thus bonded together. This process is not only used for plastics and ceramics, but also for metals. The application for metals is called Direct Metal Laser Sintering (DMLS). Laser sintering – SLS and DMLS – are counted among the industrial 3D printing processes in additive manufacturing.

Regardless of the treated material, temperature is one of the factors on which the quality of the process and thus of the final product depends to a large extent.

The granulate to be processed is applied to a building platform, the so-called powder bed surface, and preheated to a temperature below the melting point. With laser sintering of plastics, this is about 170 °C. The energy of the laser melts the individual powder particles. If this happens within the specified temperature window, the neighbouring particles subsequently bond together. The procedure is repeated layer by layer until the component is finally complete, as it has previously been stored in the laser control as a digital three-dimensional model.

Infrared cameras can be integrated directly into a laser sintering machine. With their help, users can take various measurements. Mostly relevant are the detection of the temperature distribution of the powder bed surface and the measurement of the melting temperature. Both can be realised while the laser is working - a so-called in-situ measurement. The use of laser protection windows blocks the radiation in the laser wavelength range and thus prevents the infrared camera from being damaged by the laser. At the same time these windows have a very high transmission in the wavelength range of the camera.

Another application of infrared thermography in laser sintering is the thermal analysis of the cooling of the sintered area. Areas of surface which have not been heated sufficiently or homogeneously will later show unwanted component properties which may lie outside of tolerances. This can be effectively counteracted by thermographic process control. In addition, the function and homogeneity of the radiant heaters integrated in a laser machine can be monitored with an infrared camera.

InfraTec Thermography for Laser Sintering - Picture Credits: © AdobeStock-nordroden
Laser Sintering of metal object

Laser Cutting

Cutting with a laser cutting machine is considered a low-distortion and elegant cutting method. It can be operated with high precision so that very narrow kerf widths are produced. Numerous materials can be processed without burrs, often saving complex rework. In laser cutting, also known as laser beam cutting, thermal energy is introduced into a workpiece.

InfraTec Thermography Laser Cutting - ©AdobeStock motorradcbr

A distinction is made between three different processes:

  • Melting of the cutting gap during laser beam fusion cutting,

  • Heating, melting and subsequent spontaneous combustion of the material during laser beam flame cutting or

  • Evaporation of the material during laser beam sublimation cutting.

In each type of laser cutting, the exact heat input and the heat distribution on the component surface are important factors. The workpiece is thermally affected and experiences a change in its microstructure near the cutting edge. The critical temperature for such a change in microstructure can be precisely monitored with an infrared camera.

Laser Welding

A thermography-based process control with the support of an infrared camera also proves to be beneficial for users in laser welding, for example when materials such as carbon fibre reinforced composites (CFRP) are involved. This is because the melting temperature of the carbon fibres is far higher than that of plastic matrices contained in CFRP. If heating and melting is to succeed in producing a solid joining compound, the melting and component temperature must be measured precisely with a locally high-resolution infrared camera. On this basis, reliable statements about the realised quality of the weld seam can then be made. An active-thermographic test of the weld seam afterwards is a complementary possibility to check non-destructively the achieved homogeneity of the component at the seam.

Laser welding at Laser Zentrum Hannover e.V. - Picture credits: © iStock.com / emituu

Ther­mo­graphy in CFRP Processing

Many new systems operate at very high laser intensity levels and consequently require close control of thermal processes. This is achieved by the use of infrared thermography which is both contact-less and provides imagery.

WELD-CHECK by InfraTec
Non-destructive Testing

Welding Inspec­tion – WELD-CHECK

Using pulse thermography, WELD-CHECK enables you a quantitative assessment of the inspected welds.

Active Thermography - Picture Credits: © Rainer / Fotolia.com

Active Ther­mo­graphy

Make use of active thermography for non-destructive and contact-free material testing, for both automated inline and offline solutions.

Laser welding at Laser Zentrum Hannover e.V. - Picture credits: © iStock.com / emituu

Ther­mo­graphy in CFRP Processing

Many new systems operate at very high laser intensity levels and consequently require close control of thermal processes. This is achieved by the use of infrared thermography which is both contact-less and provides imagery.

WELD-CHECK by InfraTec
Non-destructive Testing

Welding Inspec­tion – WELD-CHECK

Using pulse thermography, WELD-CHECK enables you a quantitative assessment of the inspected welds.

Active Thermography - Picture Credits: © Rainer / Fotolia.com

Active Ther­mo­graphy

Make use of active thermography for non-destructive and contact-free material testing, for both automated inline and offline solutions.

Laser Soldering

InfraTec Laser Soldering - ©InfraTec

Laser soldering is one of the processes that can be used to create substance-to-substance bond connections. The laser melts the solder, which fills the joint gap as additional material and wets and joins the components. With the laser, very specific temperature-time curves can be realised at the soldering points. Users can monitor whether these correspond to the specified process parameters with the aid of an infrared camera.

Accompanying laser soldering by thermographic analyses is relevant for example for the semiconductor, electronics and optoelectronics industries. In the course of miniaturisation, very small electronic components of only a few tenths of a millimetre are processed, as well as highly heat-sensitive parts. Selective soldering methods such as laser soft soldering must meet the requirement to precisely control the heat input and prevent damage to surrounding sensitive components.

In laser capillary gap soldering, high image frequencies of the IR camera are extremely important for reliable temperature measurement and a visual analysis of the process. In this process the liquid solder is drawn into the gap between the two objects by the capillary effect to be joined. At process temperatures of well over 1,000 °C, the laser should temper the joining zone as homogeneously as possible. The thermographic monitoring of the process provides information about the dynamic temperature changes in the gap filling process and the influence that the tempering strategy has on the formation of the temperature zones. Users can reliably derive several reactions from the data obtained:

  • Adjust temperature control strategy

  • Reduce soldering times

  • Optimise railway planning

  • Check optimum heat penetration

  • Reduce thermal stress on surrounding zones

In particular, users with special environments for such processes, like oxygen-reduced chambers, will benefit from InfraTec’s experience with applications that require special provisions such as windows and filters to make sure the imaging process works and the results are reliable. This does not only apply to the protection against splashes from the machining process. The camera's lenses in particular need to be protected from reflected laser radiation. In addition, at processing temperatures of 500 °C to 2,000 °C a filter is usually required for through-glass and high-temperature measurement. Equipped in this way, a thermography system can be used in the immediate vicinity of the laser without concern.

Indus­trial Lasers and Ther­mo­graphic Systems – a Prom­ising Combin­a­tion for the Future

Industrial lasers – just like infrared cameras – are constantly opening up new application fields. Lasers are becoming more powerful and the automation of complete processes is increasingly coming to the fore. At this point, many factors must be coordinated in order to predict process sequences and results and thus to establish fully automated and controlled processes. Thermographic measurement data, automated image evaluation and the analysis of the digital process environment provide support.

InfraTec supports this idea of innovation with the following services:

  • Cooled and uncooled high-end infrared cameras to solve complex tasks

  • Various detector formats with up to (1,920 × 1,536) IR pixels and wide temperature measurement ranges

  • Modular design for optimum adaptation to the measurement and testing situation (OEM solutions)

  • Complete range of interchangeable precision lenses with first-class transmission quality

  • Complete solutions including accessories and software for R&D and process control

  • First-class service for ensuring high system availability

  • Innovative measurement technology

Case Studies about Ther­mo­graphy Laser Applic­a­tions

Asso­ci­ated Indus­tries & Applic­a­tions

additive manufacturing

Additive Manu­fac­turing

By in-line monitoring of thermal process parameters, infrared cameras from InfraTec support the optimisation of additive manufacturing processes.

thermal imaging for automotive applications

Auto­motive Industry

Infrared camera systems help you to secure a high product quality in production and at your suppliers.

All branches and application areas