@inproceedings{64798,
  abstract     = {{Lead-containing piezoelectric ceramics are still the base for today’s ultrasonic transducers used in broad applications. This is partly due to missing powerful lead-free piezoelectric ceramic parts in the commercial market. There has been much research on lead-free materials but developing them into marketable parts seems to be an ongoing process. The actual exemption of ROHS has expired, but as the new exemption has already been requested, ceramic suppliers keep on selling lead containing products. Nevertheless, these should be replaced by lead-free alternatives for environmental and health issues. 
This contribution focuses on exploring the technological readiness level of lead-free hard piezoceramics for prestressed ultrasonic transducers. A small series of bolted Langevin transducers was set up with standard PZT material and three commercial lead-free variants. Results of the building process from individual ring ceramic characteristics to transducer load tests are presented. The main finding of this study is that the lead-free materials technically can compete with the standard PZT for medium-power applications. Some adaptations in the ultrasonic system must be done: the geometry must be altered to fit resonance frequency, and higher voltages or thinner ceramics are needed to achieve the same vibration level at low load. For reaching same power, the volume of lead-free ceramics must be 1.5 to 3 times larger. As already promoted in literature, mechanical losses at high vibration levels are smaller for the lead-free materials. This might help to argument lead-free piezoelectric materials in some applications.

References
1.	Directive 2011/65/EU of the European Parliament and of the Council of 8 June 2011 on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment. EUR-Lex Document 02011L0065-20240801. Available online: http://data.europa.eu/eli/dir/2011/65/2024-08-01 (accessed on 24 January 2025).
2.	Langevin, P. (1918) Method and Apparatus for Transmitting and Receiving Submarine Elastic Waves Using the Piezoelectric Properties of Quartz. French Patent Office; Patent No. FR505703.
3.	Hemsel, T.; Twiefel, J. (2023) Piezoelectric Ultrasonic Power Transducers. In Encyclopedia of Materials: Electronics; Academic Press: Oxford, UK; pp. 276–285. https://doi.org/10.1016/b978-0-12-819728-8.00047-4.
4.	ATHENA Technologie Beratung GmbH (2025) Description of Ultrasound Generator. Available online: http://shop.myathena.de/epages/12074748.sf/de_DE/?ObjectPath=/Shops/12074748/Products/AM200 (accessed on 13 January 2025).
5.	Littmann, W.; Hemsel, T.; Kauczor, C.; Wallaschek, J.; Sinha, W. (2003) Load-adaptive phase-controller for resonant driven piezoelectric devices. Proc. World Congr. Ultrason. 2003, 48, 547–550.
6.	Scheidemann, C., Bornmann, P., Littmann, W., & Hemsel, T. (2025). Lead-Free Ceramics in Prestressed Ultrasonic Transducers. Actuators, 14(2), 55. https://doi.org/10.3390/act14020055
}},
  author       = {{Scheidemann, Claus and Bornmann, Peter and Littmann, Walter and Hemsel, Tobias}},
  keywords     = {{lead free piezoelectric ceramics, bolted Langevin transducer, medium power ultrasound.}},
  location     = {{Vilnius, Lithuania}},
  title        = {{{Bolted Langevin transducers with leadfree piezoelectric ceramics}}},
  year         = {{2025}},
}

@article{53621,
  abstract     = {{<jats:p>The coupling of structural transitions to heat capacity changes leads to destabilization of macromolecules at both, elevated and lowered temperatures. DNA origami not only exhibit this property but also provide...</jats:p>}},
  author       = {{Dornbusch, Daniel and Hanke, Marcel and Tomm, Emilia and Kielar, Charlotte and Grundmeier, Guido and Keller, Adrian and Fahmy, Karim}},
  issn         = {{1359-7345}},
  journal      = {{Chemical Communications}},
  keywords     = {{Materials Chemistry, Metals and Alloys, Surfaces, Coatings and Films, General Chemistry, Ceramics and Composites, Electronic, Optical and Magnetic Materials, Catalysis}},
  publisher    = {{Royal Society of Chemistry (RSC)}},
  title        = {{{Cold denaturation of DNA origami nanostructures}}},
  doi          = {{10.1039/d3cc05985e}},
  year         = {{2024}},
}

@article{43095,
  author       = {{Lenz, Peter and Mahnken, Rolf}},
  issn         = {{0263-8223}},
  journal      = {{Composite Structures}},
  keywords     = {{Civil and Structural Engineering, Ceramics and Composites}},
  publisher    = {{Elsevier BV}},
  title        = {{{Non-local integral-type damage combined to mean-field homogenization methods for composites and its parallel implementation}}},
  doi          = {{10.1016/j.compstruct.2023.116911}},
  year         = {{2023}},
}

@article{44078,
  author       = {{Andreiev, Anatolii and Hoyer, Kay-Peter and Hengsbach, Florian and Haase, Michael and Tasche, Lennart and Duschik, Kristina and Schaper, Mirko}},
  issn         = {{0924-0136}},
  journal      = {{Journal of Materials Processing Technology}},
  keywords     = {{Industrial and Manufacturing Engineering, Metals and Alloys, Computer Science Applications, Modeling and Simulation, Ceramics and Composites}},
  publisher    = {{Elsevier BV}},
  title        = {{{Powder bed fusion of soft-magnetic iron-based alloys with high silicon content}}},
  doi          = {{10.1016/j.jmatprotec.2023.117991}},
  volume       = {{317}},
  year         = {{2023}},
}

@article{64044,
  abstract     = {{Abstract Polymer-derived silicon oxycarbide ceramics (SiCO) have been considered as potential anode materials for lithium- and sodium-ion batteries. To understand their electrochemical storage behavior, detailed insights into structural sites present in SiCO are required. In this work, the study of local structures in SiCO ceramics containing different amounts of carbon is presented. 13C and 29Si solid-state MAS?NMR spectroscopy combined with DFT calculations, atomistic modeling, and EPR investigations, suggest significant changes in the local structures of SiCO ceramics even by small changes in the material composition. The provided findings on SiCO structures will contribute to the research field of polymer-derived ceramics, especially to understand electrochemical storage processes of alkali metal/ions such as Na/Na+ inside such networks in the future.}},
  author       = {{Šić, Edina and Rohrer, Jochen and Ricohermoso, Emmanuel and Albe, Karsten and Ionescu, Emmanuel and Riedel, Ralf and Breitzke, Hergen and Gutmann, Torsten and Buntkowsky, Gerd}},
  issn         = {{1864-5631}},
  journal      = {{Chemsuschem}},
  keywords     = {{NMR spectroscopy, Ceramics, defects, density functional calculations, EPR spectroscopy}},
  pages        = {{e202202241}},
  publisher    = {{John Wiley & Sons, Ltd}},
  title        = {{{SiCO Ceramics as Storage Materials for Alkali Metals/Ions: Insights on Structure Moieties from Solid-State NMR and DFT Calculations}}},
  doi          = {{10.1002/cssc.202202241}},
  volume       = {{16}},
  year         = {{2023}},
}

@article{30922,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>Pure iron is very attractive as a biodegradable implant material due to its high biocompatibility. In combination with additive manufacturing, which facilitates great flexibility of the implant design, it is possible to selectively adjust the microstructure of the material in the process, thereby control the corrosion and fatigue behavior. In the present study, conventional hot-rolled (HR) pure iron is compared to pure iron manufactured by electron beam melting (EBM). The microstructure, the corrosion behavior and the fatigue properties were studied comprehensively. The investigated sample conditions showed significant differences in the microstructures that led to changes in corrosion and fatigue properties. The EBM iron showed significantly lower fatigue strength compared to the HR iron. These different fatigue responses were observed under purely mechanical loading as well as with superimposed corrosion influence and are summarized in a model that describes the underlying failure mechanisms.</jats:p>}},
  author       = {{Wackenrohr, Steffen and Torrent, Christof Johannes Jaime and Herbst, Sebastian and Nürnberger, Florian and Krooss, Philipp and Ebbert, Christoph and Voigt, Markus and Grundmeier, Guido and Niendorf, Thomas and Maier, Hans Jürgen}},
  issn         = {{2397-2106}},
  journal      = {{npj Materials Degradation}},
  keywords     = {{Materials Chemistry, Materials Science (miscellaneous), Chemistry (miscellaneous), Ceramics and Composites}},
  number       = {{1}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Corrosion fatigue behavior of electron beam melted iron in simulated body fluid}}},
  doi          = {{10.1038/s41529-022-00226-4}},
  volume       = {{6}},
  year         = {{2022}},
}

@article{30911,
  author       = {{Vorderbrüggen, Julian and Köhler, Daniel and Grüber, Bernd and Troschitz, Juliane and Gude, Maik and Meschut, Gerson}},
  issn         = {{0263-8223}},
  journal      = {{Composite Structures}},
  keywords     = {{Civil and Structural Engineering, Ceramics and Composites}},
  publisher    = {{Elsevier BV}},
  title        = {{{Development of a rivet geometry for solid self-piercing riveting of thermally loaded CFRP-metal joints in automotive construction}}},
  doi          = {{10.1016/j.compstruct.2022.115583}},
  volume       = {{291}},
  year         = {{2022}},
}

@article{32330,
  author       = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Hengsbach, Florian and Schaper, Mirko}},
  issn         = {{2238-7854}},
  journal      = {{Journal of Materials Research and Technology}},
  keywords     = {{Metals and Alloys, Surfaces, Coatings and Films, Biomaterials, Ceramics and Composites}},
  pages        = {{2369--2387}},
  publisher    = {{Elsevier BV}},
  title        = {{{Formation of insoluble silver-phases in an iron-manganese matrix for bioresorbable implants using varying laser beam melting strategies}}},
  doi          = {{10.1016/j.jmrt.2022.06.006}},
  volume       = {{19}},
  year         = {{2022}},
}

@article{34256,
  abstract     = {{<jats:p>The 3D shear deformation and failure behaviour of a glass fibre reinforced polypropylene in a shear strain rate range of γ˙=2.2×10−4 to 3.4 1s is investigated. An Iosipescu testing setup on a servo-hydraulic high speed testing unit is used to experimentally characterise the in-plane and out-of-plane behaviour utilising three specimen configurations (12-, 13- and 31-direction). The experimental procedure as well as the testing results are presented and discussed. The measured shear stress–shear strain relations indicate a highly nonlinear behaviour and a distinct rate dependency. Two methods are investigated to derive according material characteristics: a classical engineering approach based on moduli and strengths and a data driven approach based on the curve progression. In all cases a Johnson–Cook based formulation is used to describe rate dependency. The analysis methodologies as well as the derived model parameters are described and discussed in detail. It is shown that a phenomenologically enhanced regression can be used to obtain material characteristics for a generalising constitutive model based on the data driven approach.</jats:p>}},
  author       = {{Gerritzen, Johannes and Hornig, Andreas and Gröger, Benjamin and Gude, Maik}},
  issn         = {{2504-477X}},
  journal      = {{Journal of Composites Science}},
  keywords     = {{Engineering (miscellaneous), Ceramics and Composites}},
  number       = {{10}},
  publisher    = {{MDPI AG}},
  title        = {{{A Data Driven Modelling Approach for the Strain Rate Dependent 3D Shear Deformation and Failure of Thermoplastic Fibre Reinforced Composites: Experimental Characterisation and Deriving Modelling Parameters}}},
  doi          = {{10.3390/jcs6100318}},
  volume       = {{6}},
  year         = {{2022}},
}

@article{33671,
  abstract     = {{<jats:title>Abstract</jats:title>
               <jats:p>We demonstrate the fabrication of micron-wide tungsten silicide superconducting nanowire single-photon detectors on a silicon substrate using laser lithography. We show saturated internal detection efficiencies with wire widths ranging from 0.59 <jats:italic>µ</jats:italic>m to 1.43 <jats:italic>µ</jats:italic>m under illumination at 1550 nm. We demonstrate both straight wires, as well as meandered structures. Single-photon sensitivity is shown in devices up to 4 mm in length. Laser-lithographically written devices allow for fast and easy structuring of large areas while maintaining a saturated internal efficiency for wire widths around 1 <jats:italic>µ</jats:italic>m.</jats:p>}},
  author       = {{Protte, Maximilian and Verma, Varun B and Höpker, Jan Philipp and Mirin, Richard P and Woo Nam, Sae and Bartley, Tim}},
  issn         = {{0953-2048}},
  journal      = {{Superconductor Science and Technology}},
  keywords     = {{Materials Chemistry, Electrical and Electronic Engineering, Metals and Alloys, Condensed Matter Physics, Ceramics and Composites}},
  number       = {{5}},
  publisher    = {{IOP Publishing}},
  title        = {{{Laser-lithographically written micron-wide superconducting nanowire single-photon detectors}}},
  doi          = {{10.1088/1361-6668/ac5338}},
  volume       = {{35}},
  year         = {{2022}},
}

@article{31185,
  author       = {{Ju, Xiaozhe and Mahnken, Rolf and Xu, Yangjian and Liang, Lihua and Cheng, Chun and Zhou, Wangmin}},
  issn         = {{0263-8223}},
  journal      = {{Composite Structures}},
  keywords     = {{Civil and Structural Engineering, Ceramics and Composites}},
  publisher    = {{Elsevier BV}},
  title        = {{{Multiscale analysis of composite structures with goal-oriented mesh adaptivity and reduced order homogenization}}},
  doi          = {{10.1016/j.compstruct.2022.115699}},
  year         = {{2022}},
}

@article{40564,
  abstract     = {{<jats:p>The reported N-doped noble carbonaceous support provides strong stabilization of Mn(<jats:sc>ii</jats:sc>) sub-nanometric active sites as well as a convenient coordination environment to produce CO, HCOOH and CH<jats:sub>3</jats:sub>COOH from electrochemical CO<jats:sub>2</jats:sub> reduction.</jats:p>}},
  author       = {{Kossmann, Janina and Sánchez-Manjavacas, Maria Luz Ortiz and Brandt, Jessica and Heil, Tobias and Lopez Salas, Nieves and Albero, Josep}},
  issn         = {{1359-7345}},
  journal      = {{Chemical Communications}},
  keywords     = {{Materials Chemistry, Metals and Alloys, Surfaces, Coatings and Films, General Chemistry, Ceramics and Composites, Electronic, Optical and Magnetic Materials, Catalysis}},
  number       = {{31}},
  pages        = {{4841--4844}},
  publisher    = {{Royal Society of Chemistry (RSC)}},
  title        = {{{Mn(<scp>ii</scp>) sub-nanometric site stabilization in noble, N-doped carbonaceous materials for electrochemical CO<sub>2</sub> reduction}}},
  doi          = {{10.1039/d2cc00585a}},
  volume       = {{58}},
  year         = {{2022}},
}

@article{33856,
  abstract     = {{<jats:p>Wood–plastic composites (WPC) are enjoying a steady increase in popularity. In addition to the extrusion of decking boards, the material is also used increasingly in injection molding. Depending on the formulation, geometry and process parameters, WPC tends to exhibit irregular filling behavior, similar to the processing of thermosets. In this work, the influence of matrix material and wood fiber content on the flow, mold filling and segregation behavior of WPC is analyzed. For this purpose, investigations were carried out on a flow spiral and a sheet cavity. WPC based on thermoplastic polyurethane (TPU) achieves significantly higher flow path lengths at a wood mass content of 30% than polypropylene (PP)-based WPC. The opposite behavior occurs at higher wood contents due to the different shear thinning behavior. Slightly decreased wood contents could be observed at the beginning of the flow path and greatly increased wood contents at the end of the flow path, compared to the starting material. When using the plate cavity, flow anomalies in the form of free jets occur as a function of the wood content, with TPU exhibiting the more critical behavior. The flow front is frayed, but in contrast to the flow spiral, no significant wood accumulation could be detected due to the shorter flow path lengths.</jats:p>}},
  author       = {{Moritzer, Elmar and Flachmann, Felix and Richters, Maximilian and Neugebauer, Marcel}},
  issn         = {{2504-477X}},
  journal      = {{Journal of Composites Science}},
  keywords     = {{Engineering (miscellaneous), Ceramics and Composites}},
  number       = {{10}},
  publisher    = {{MDPI AG}},
  title        = {{{Analysis of the Segregation Phenomena of Wood Fiber Reinforced Plastics}}},
  doi          = {{10.3390/jcs6100321}},
  volume       = {{6}},
  year         = {{2022}},
}

@article{34097,
  author       = {{Voswinkel, Dietrich and Striewe, Jan Andre and Grydin, Olexandr and Meinderink, Dennis and Grundmeier, Guido and Schaper, Mirko and Tröster, Thomas}},
  issn         = {{0924-3046}},
  journal      = {{Advanced Composite Materials}},
  keywords     = {{Mechanical Engineering, Mechanics of Materials, Ceramics and Composites}},
  pages        = {{1--16}},
  publisher    = {{Informa UK Limited}},
  title        = {{{Co-bonding of carbon fibre-reinforced epoxy and galvanised steel with laser structured interface for automotive applications}}},
  doi          = {{10.1080/09243046.2022.2143746}},
  year         = {{2022}},
}

@article{32332,
  author       = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Hengsbach, Florian and Schaper, Mirko}},
  issn         = {{2238-7854}},
  journal      = {{Journal of Materials Research and Technology}},
  keywords     = {{Metals and Alloys, Surfaces, Coatings and Films, Biomaterials, Ceramics and Composites}},
  pages        = {{2369--2387}},
  publisher    = {{Elsevier BV}},
  title        = {{{Formation of insoluble silver-phases in an iron-manganese matrix for bioresorbable implants using varying laser beam melting strategies}}},
  doi          = {{10.1016/j.jmrt.2022.06.006}},
  volume       = {{19}},
  year         = {{2022}},
}

@article{41498,
  author       = {{Krüger, Jan Tobias and Hoyer, Kay-Peter and Hengsbach, Florian and Schaper, Mirko}},
  issn         = {{2238-7854}},
  journal      = {{Journal of Materials Research and Technology}},
  keywords     = {{Metals and Alloys, Surfaces, Coatings and Films, Biomaterials, Ceramics and Composites}},
  pages        = {{2369--2387}},
  publisher    = {{Elsevier BV}},
  title        = {{{Formation of insoluble silver-phases in an iron-manganese matrix for bioresorbable implants using varying laser beam melting strategies}}},
  doi          = {{10.1016/j.jmrt.2022.06.006}},
  volume       = {{19}},
  year         = {{2022}},
}

@article{31496,
  abstract     = {{<jats:p>Carbon fiber reinforced plastics (CFRPs) gained high interest in industrial applications because of their excellent strength and low specific weight. The stacking sequence of the unidirectional plies forming a CFRP laminate, and their thicknesses, primarily determine the mechanical performance. However, during manufacturing, defects, e.g., pores and residual stresses, are induced, both affecting the mechanical properties. The objective of the present work is to accurately measure residual stresses in CFRPs as well as to investigate the effects of stacking sequence, overall laminate thickness, and the presence of pores on the residual stress state. Residual stresses were measured through the incremental hole-drilling method (HDM). Adequate procedures have been applied to evaluate the residual stresses for orthotropic materials, including calculating the calibration coefficients through finite element analysis (FEA) based on stacking sequence, laminate thickness and mechanical properties. Using optical microscopy (OM) and computed tomography (CT), profound insights into the cross-sectional and three-dimensional microstructure, e.g., location and shape of process-induced pores, were obtained. This microstructural information allowed for a comprehensive understanding of the experimentally determined strain and stress results, particularly at the transition zone between the individual plies. The effect of pores on residual stresses was investigated by considering pores to calculate the calibration coefficients at a depth of 0.06 mm to 0.12 mm in the model and utilizing these results for residual stress evaluation. A maximum difference of 46% in stress between defect-free and porous material sample conditions was observed at a hole depth of 0.65 mm. The significance of employing correctly calculated coefficients for the residual stress evaluation is highlighted by mechanical validation tests.</jats:p>}},
  author       = {{Wu, Tao and Kruse, Roland and Tinkloh, Steffen Rainer and Tröster, Thomas and Zinn, Wolfgang and Lauhoff, Christian and Niendorf, Thomas}},
  issn         = {{2504-477X}},
  journal      = {{Journal of Composites Science}},
  keywords     = {{Engineering (miscellaneous), Ceramics and Composites}},
  number       = {{5}},
  publisher    = {{MDPI AG}},
  title        = {{{Experimental Analysis of Residual Stresses in CFRPs through Hole-Drilling Method: The Role of Stacking Sequence, Thickness, and Defects}}},
  doi          = {{10.3390/jcs6050138}},
  volume       = {{6}},
  year         = {{2022}},
}

@article{32814,
  author       = {{Wu, T. and Degener, S. and Tinkloh, Steffen Rainer and Liehr, A. and Zinn, W. and Nobre, J.P. and Tröster, Thomas and Niendorf, T.}},
  issn         = {{0263-8223}},
  journal      = {{Composite Structures}},
  keywords     = {{Civil and Structural Engineering, Ceramics and Composites}},
  publisher    = {{Elsevier BV}},
  title        = {{{Characterization of residual stresses in fiber metal laminate interfaces - A combined approach applying hole-drilling method and energy-dispersive X-ray diffraction}}},
  doi          = {{10.1016/j.compstruct.2022.116071}},
  year         = {{2022}},
}

@article{30510,
  abstract     = {{The corrosion behavior of a hybrid material consisting of intrinsically bonded carbon fiber-reinforced epoxy resin with laser-structured EN AW 6082 metal was investigated. Particular attention was paid to the effects of the laser-structuring, surface topography and the contacting. Pristine and hybridized specimens were corroded in aqueous NaCl electrolyte (0.1 mol/l) using a potentiodynamic polarization technique and subsequently analyzed using computed tomography, scanning electron-, light- and laser scanning microscopy. The results show that the corrosive reaction arises mainly from the aluminum component. Surface pretreatment of the aluminum resulted in increasing corrosion rates, but showed no influence on the hybrids corrosion properties. Optical micrographs suggest that the epoxy resin acts as a sealant preventing galvanic corrosion between the aluminum and carbon fibers by hindering the diffusion of the electrolyte into the joints. While corrosion effects were observed locally at the aluminum surface, they were, contrary to expectations, not enhanced on the hybrid interfaces.}},
  author       = {{Delp, Alexander and Freund, Jonathan and Wu, Shuang and Scholz, Ronja and Löbbecke, Miriam and Haubrich, Jan and Tröster, Thomas and Walther, Frank}},
  issn         = {{0263-8223}},
  journal      = {{Composite Structures}},
  keywords     = {{Civil and Structural Engineering, Ceramics and Composites}},
  publisher    = {{Elsevier BV}},
  title        = {{{Influence of laser-generated surface micro-structuring on the intrinsically bonded hybrid system CFRP-EN AW 6082-T6 on its corrosion properties}}},
  doi          = {{10.1016/j.compstruct.2022.115238}},
  volume       = {{285}},
  year         = {{2022}},
}

@article{30924,
  abstract     = {{<jats:p>Wood fiber reinforcement of plastics is almost limited to polypropylene, polyethylene, polyvinyl chloride and polystyrene. Wood fiber reinforcement of thermoplastic polyurethanes (TPU) is a new research field and paltry studied scientifically. Wood fiber reinforcement can carry out synergistic effects between sustainability, material or product price reduction, improved mechanical properties at high elongation, and brilliant appearance and haptics. In order to evaluate to what extent the improvement of mechanical properties depend on material-specific parameters (fiber type, fiber content) and on process-specific parameters (holding pressure, temperature control and injection speed), differently filled compounds were injection molded according to a partial factorial test plan and subjected to characterizing test procedures (tensile test, Shore hardness and notched impact test). Tensile strength showed significant dependence on barrel temperature, fiber type and interaction between holding pressure and barrel temperature in the region of interest. Young’s modulus can be influenced by fiber content but not by fiber type. Notched impact strength showed a significant influence of cylinder temperature, fiber content, fiber type and the interaction between cylinder temperature and fiber content in the region of interest. Shore hardness is related to fiber content and the interaction between mold temperature and injection flow rate. Our results show not only that wood-filled TPU can be processed very well by injection molding, but also that the mechanical properties depend significantly on temperature control in the injection-molding process. Moreover, considering the significant reinforcing effect of the wood fibers, a good fiber-matrix adhesion can be assumed.</jats:p>}},
  author       = {{Moritzer, Elmar and Richters, Maximilian}},
  issn         = {{2504-477X}},
  journal      = {{Journal of Composites Science}},
  keywords     = {{Engineering (miscellaneous), Ceramics and Composites}},
  number       = {{12}},
  publisher    = {{MDPI AG}},
  title        = {{{Injection Molding of Wood-Filled Thermoplastic Polyurethane}}},
  doi          = {{10.3390/jcs5120316}},
  volume       = {{5}},
  year         = {{2021}},
}