Effect of carbon nanotube on the mechanical properties of short carbon fiber reinforced polyether-ether-ketone

Abstract

Additive manufacturing provides a quick and cost-effective way for the fabrication of complex composite structures. Additively manufactured short carbon fiber reinforced polyether-ether-ketone (SCF/PEEK) is a promising thermoplastic composite material due to its excellent designability, ease of manufacture, and good recyclability. However, the mechanical properties of 3D printed SCF/PEEK are unsatisfactory due to the layer-by-layer forming process. In this study, CNTs were introduced to 3D printed SCF/PEEK, and the influence mechanism of CNTs on the mechanical properties was analyzed and discussed in depth. The results showed that the introduction of CNTs could effectively enhance the tensile modulus of 3D printed SCF/PEEK, whilst it led to a decrease in the tensile strength and interlaminar shear strength of the composites. This was mainly related to the poor dispersion and agglomeration of CNTs. The modulus of 3D printed SCF/PEEK reached about 5.17 GPa, representing a 95.1% increase.

Keywords

3D printing short carbon fiber composite carbon nanotube mechanical property

Introduction

Compared with other materials such as metal alloys, fiber composites have the advantages of lightweight, high strength, fatigue and corrosion resistance. Therefore, fiber composites are widely used in fields such as aerospace, rail transit, marine vessels, biomedicine, and new energy.^1–3 Compared with thermoset matrix composites, thermoplastic matrix composites that possess recyclability and high-impact strength have gained increasing attention. Among them, polyether-ether-ketone (PEEK) is a high-performance thermoplastic special engineering plastic with low density, high strength, high wear resistance, excellent thermal stability, high load-bearing capacity, and good processing performance, and is one of the best matrix materials for high-temperature wear resistance.^4,5 However, the mechanical properties of pure PEEK do not meet the requirements of harsh environments.⁶ To improve the mechanical properties of polymer materials, fibers are widely used as reinforcement materials because of their excellent mechanical properties, high thermal and electrical conductivity, excellent corrosion resistance, low thermal expansion coefficient, and low density.⁷ Carbon fiber (CF) has been reported to be the most common and effective type of reinforcement to enhance the mechanical properties of PEEK.⁴ Short carbon fiber (SCF) reinforced PEEK (SCF/PEEK) composites have garnered significant attention due to their ease of manufacture, ability to be processed into complex geometric shapes, cost-effectiveness, and excellent mechanical properties.⁸

However, the weak interfacial bonding of SCF/PEEK composites limits their further development.⁹ The main methods used in current research to improve the interfacial bonding between CF and PEEK are chemical and physical modifications.¹⁰ Chemical modification involves adding reactive functional groups or substances with reactive functional groups, employing methods such as chemical grafting, coating treatment, or chemical activation.^11–13 However, due to the structural properties of PEEK macromolecular chains, establishing robust chemical interactions between PEEK and CF still is challenging. Furthermore, the processing temperature of the composites can disrupt the modified chemical bonds.¹⁴ Therefore, the most effective approach for improving the interfacial bonding of CF/PEEK composites is through physical modification.

When added to composites, nanoparticles cannot only improve the interfacial mechanical interlocking but also enhance the chemical interactions at the interface. In this way, the mechanical properties of the composites can be effectively strengthened.^15–17 Carbon nanotubes (CNTs) have a high specific surface area and aspect ratio, as well as excellent mechanical, electrical, and thermal properties. Thus, CNTs are widely used for improving the mechanical properties of composites.^18–20 For example, Shen et al.²¹ investigated the incorporation of CNTs into polyamide-6 (PA6) to produce glass fiber reinforced laminates. The result showed incorporation of 2 wt% CNT in CNT/PA6/GF laminates improved the flexural stress of the laminates by up to 36%. Painkal et al.²² fabricated the introduction of CNTs into polyaryletherketone (PAEK) film through melting techniques and investigated performance improvement in CNTs reinforced PAEK-CF composites. The research indicated when CNTs were added, the ILSS increased by 21%. Yao et al.²³ prepared a hierarchical structure of CNTs grown on CF by a chemical vapor deposition (CVD) method. The results showed the interlaminar shear strength (ILSS) and interfacial shear strength (IFSS) of its composites were 19.50% and 62.32% higher than that of the CF/epoxy composites without CNTs grown, respectively. Su et al.¹¹ sprayed CNTs onto a CF/PEEK prepreg and prepared laminated plates through the hot pressing molding process. The introduction of 0.5 wt% CNTs increased the interlaminar shear strength (ILSS) of the CF/PEEK composites by 35.8%. Ma et al.⁶ obtained PEEK nanocomposites by melt blending PEEK/CNTs/MMT particles with PEEK powder and injection molding. The results showed that when 0.5 wt% CNTs were added, the storage modulus increased by 48.1% compared to pure PEEK. The improved mechanical strength of these composite materials was widely applied in aerospace, marine vessels and rail transportation et al.

3D printing, also known as additive manufacturing (AM), enables the fabrication of complex 3D parts based on 3D computer-aided design (CAD) data.²⁴ Compared with traditional manufacturing techniques such as compression molding, extrusion molding resin transfer molding et al, which require specific molds or tools that are costly and inflexible, 3D printing could fabricate near-net-shape complex parts without expensive molds and tools in short periods, and also offers the advantages of high raw material utilization and significant forming flexibility.^25,26 However, a key challenge is the relatively inferior mechanical properties of the printed composites compared to those fabricated by traditional methods.²⁷ Therefore, CNTs were introduced to SCF/PEEK during the additive manufacturing process and their effects on the morphological and mechanical properties were investigated. The influence mechanism of CNTs on the mechanical properties was analyzed and discussed in depth.

Experiment

Experimental materials

TNMC3 carbon nanotubes (CNTs) with an outer diameter of 10–20 nm were purchased from Chengdu Organic Chemistry Co. Ltd. of the Chinese Academy of Sciences. Toho HTS40 short carbon fibers (SCF) with a length of 75–150 μm were purchased by Nanjing Weida Composites Co. Ltd. The 310G polyether-ether-ketone (PEEK) was purchased from Jilin Zhongyan Polymer Co. Ltd, and the particle size of PEEK pellets is around 3 mm.

Preparation of C/S/P mixed granular materials

The melt granulation process was employed to prepare the C/S/P mixed granular materials, ensuring the even mixing of CNTs, SCF, and PEEK raw materials. CNTs, SCF and PEEK were dried in an oven at 150°C for 4 h, which could prevent moisture in the raw materials from generating pore defects during granulation. Subsequently, different materials were weighted by an electronic balance, where SCF was 100 g, PEEK was 900, 895, 890, 870, and 855 g, and the weight of corresponding CNTs was 0, 5, 10, 30, and 45 g, respectively. The materials were thoroughly mixed using mechanical agitation to prepare 0, 0.5 wt%, 1.0 wt%, 3.0 wt%, and 4.5 wt% CNTs content of the mixture. The mixed materials were immediately added to the feed inlet of the twin-screw extruder of the granulator (FLD-25B, China). The heating zone of the twin-screw extruder should maintain at approximately 344°C to melt resin and avoid the thermal decomposition of the resin, which may damage the performance of samples at higher temperatures. Collaborative control of feeding, extrusion, and conveyor belt speeds facilitated the extrusion of a filamentous mixture with a suitable diameter. After air cooling the filaments, appropriate cutting speeds were applied to obtain mixed granular materials with suitable lengths (∼3 mm) (Figure 1(a)). Finally, the obtained mixed granular materials were dried and stored at room temperature. The mixed composites were named as C/S/P and SCF/PEEK composites without CNT were named as S/P. (Table 1).

Table 1.

Nomenclature of different content of CNTs introduced into SCF and PEEK.

Name	PEEK/wt%	SCF/wt%	CNTs/wt%
S/P	90.0	10	0
0.5 C/S/P	89.5	10	0.5
1.0 C/S/P	89.0	10	1.0
3.0 C/S/P	87.0	10	3.0
4.5 C/S/P	85.5	10	4.5

Preparation of C/S/P filaments

To prepare composites using the additive manufacturing process, the mixed granular materials needed further processing to obtain composite filaments. The C/S/P granular materials were introduced into the feed inlet of the filament machine (TDS-20, China), which was heated to around 344°C. Maintaining the correct melting temperature was crucial. If the temperature was too low, the composite was hard to be extruded, and too high, degradation of the composite might occur. According to the content of CNTs, appropriate extrusion speed and pulling speed were applied to produce filaments with a specific diameter. The diameter of this filament was 1.75 ± 0.1 mm, which met the additive manufacturing process requirements (Figure 1(b)).

Characterization of mechanical properties of C/S/P filaments

To research the influence of the CNTs introduction on the mechanical properties of filaments, the tensile test was carried out. According to the standard of ASTM D4018-11 the tensile samples were prepared with a length of 250 mm, and its two ends were fixed by strengthening plates. Finally, the 2 mm/min of tensile speed was applied to measure with the universal testing machine (CMT10 L, China). Meanwhile, the extensometer was used to record axial deformation.

Morphological analysis of C/S/P filaments

To observe the dispersion and distribution of CNTs in SCF/PEEK composite, the fracture surface micromorphology of the filament was observed using a dual beam scanning electron microscope (SEM, TESCAN LYRA3 GM, Czech Republic). The cross-section of the filament was exposed on the sample holder and coated with a layer of gold for analysis.

Additive manufacturing process to prepare test samples

To explore the influence of the addition of CNTs on the mechanical properties of SCF/PEEK composites in the additive manufacturing process, test samples were prepared using a composite 3D printer (MAGIC-HT-PRO, IEMAI). The C/S/P filament was fed into the 3D printing nozzle and melted. The printing parameter settings included the printing speed (30 mm/s), the printing direction (0°), the nozzle temperature (440°C), the baseplate temperature (120°C), the printing layer thickness (0.2 mm) and the chamber temperature (90°C) (Figure 1(c)).

Characterization of mechanical properties of C/S/P composites

The mechanical properties of C/S/P composites were analyzed to evaluate the effect of the addition of CNTs on the mechanical properties of S/P composites. Tensile testing of the samples was carried out using a universal testing machine (INSTRON 3343, USA). According to the ISO 527-2 test standard, IBA dumbbell-type samples with a clamping distance of 60 mm and a gauge length of 25 mm were prepared, and the test speed was 1 mm/min. Furthermore, extensometers were attached to both ends of the sample to measure axial deformation during the tensile test.

Interlaminar shear strength (ILSS) tests were performed based on ASTM D2344. The test samples measured 40 × 12 × 6 mm, with a span-to-thickness ratio of 4:1, a span length of 24 mm, an indenter diameter of 3 mm, and a loading speed of 1.0 mm/min.

Sample morphology and porosity characterization

The influence mechanism of CNTs on the mechanical properties of SCF/PEEK composites was investigated by observing the micromorphology of the tensile fracture surface. The fracture surface of the tensile fracture sample was exposed on the sample holder and sprayed with gold. The micromorphology of the tensile fracture surfaces was observed using a dual beam SEM (TESCAN LYRA3 GM, Czech Republic).

The porosity of the sample revealed internal defects within the printed sample. The density of tensile and interlaminar shear samples was measured using a solid density meter (JHY-300, China). The equation for calculating the porosity of the samples is expressed as follows:

P = \frac{ρ_{1} - ρ_{2}}{ρ_{1}} \times 100 %

where P is the porosity of the sample (%), ρ₁ is the theoretical density of the sample (g/cm³), and ρ₂ is the actual density of the sample (g/cm³). Among them, the calculation formula of ρ₁ was shown:

ρ_{1} = ρ_{c} V_{c} + ρ_{s} V_{s} + ρ_{p} V_{p}

V_{n} = \frac{\frac{m_{n}}{ρ_{n}}}{\frac{m_{c}}{ρ_{c}} + \frac{m_{s}}{ρ_{s}} + \frac{m_{p}}{ρ_{p}}}

where ρ_c (2.1 g/cm³),V_c and m_c indicate the density, volume fraction and mass fraction of the CNTs of C/S/P composites, respectively; ρ_s (1.77 g/cm³),V_s and m_s are the density, volume fraction, and mass fraction of the SCF of C/S/P composites, respectively; ρ_p (1.3 g/cm³),V_p and m_p respent the density, volume fraction and mass fraction of the PEEK of C/S/P composites, respectively. Among, n is the ingredient of C/S/P composites.

Crysitilization behavior of C/S/P composites

As a linear semi-crystalline thermoplastic, the mechanical strength of PEEK mainly originated from the crystal phase.²⁸ Therefore, exploring the crystallinization properties of PEEK of C/S/P composites is significant. Differential scanning calorimetry (DSC) measurements were performed with a differential scanning calorimeter (TA, DSC250, USA). The samples were heated from 30 to 500°C at a heating rate of 25°C/min under nitrogen atmosphere. The scan rate of 25°C/min was chosen to avoid recrystallization on heating and maintain enough accuracy.²⁹ The crystallinity was calculated according to the equation as follows:

X_{c} = \frac{| {∆ H}_{m} | - | {∆ H}_{c c} |}{w_{p} | {∆ H}_{f} |}

where X_c represents the crystallinity of PEEK, ΔH_m is enthalpy of melting, ΔH_cc denotes enthalpy of cold crystallization, ΔH_f is enthalpy of melting of 100% crystalline of PEEK, the value of which is 130 J/g, and w_p is the weight fraction of PEEK.²⁸

Results and discussion

Figure 2 shows the variation in tensile properties of SCF/PEEK filaments with varying CNT content. It can be seen that the tensile modulus and strength of pure SCF/PEEK is 4.86 ± 0.27 GPa and 87.10 ± 3.22 MPa, respectively. The tensile modulus of the C/S/P filaments increases with increasing CNT content, evidencing a reinforcing effect on SCF/PEEK due to the addition of CNTs. The highest tensile modulus increased to 5.59 ± 0.12 GPa (4.5 C/S/P filament), representing an improvement of 15.0%. However, the trend in tensile strength differs, showing an initial decrease followed by an increase trend. 1.0 C/S/P filament possessed the lowest tensile strength of 68.61 ± 7.65 MPa, representing a 21.2% decrease compared to S/P filament. This suggests that in addition to the strengthening effect, the introduction of CNT must have resulted in other effects, which will be further elaborated upon in the subsequent sections.

Figure 3 shows the micromorphology of the C/S/P composite filaments. In this study, numerous pore defects were generated in all filaments. In addition, the pore size was significantly larger than the SCF diameter, indicating that air retention occurred during the composite filament preparation by melt blending and melt drawing.³⁰ Moreover, the introduction of CNTs did not reduce the generation of pore defects in the composite filaments. Compared to the uniform distribution of pores in the S/P composite filaments, the pores in the C/S/P composite filaments were mainly concentrated in a certain part of the filaments. This may result in stress concentration and premature failure of C/S/P composites (Figure 3(a)). Further observation of the interfacial bonding between SCF and PEEK revealed that SCF was not encapsulated by PEEK in all composite filaments, indicating that the addition of CNTs in the SCF/PEEK composite filaments did not improve the interfacial adhesion between SCF and PEEK (Figure 3(b)). Furthermore, the PEEK matrix exhibited granular nanostructures in the SCF/PEEK composite filaments. However, after the CNTs were added to the composite filaments, tubular nanostructure can be observed which represented agglomeration of CNTs. This may cause the weakened mechanical properties (Figure 3(c)).

To further enhance the mechanical properties of SCF/PEEK composites and expand their application areas, different content CNTs were added to the SCF/PEEK composites. Figure 4 shows the effect of different content CNTs on the tensile properties of the SCF/PEEK composites. The stress–strain curves demonstrated that the tensile modulus of the SCF/PEEK composites increased with an increasing CNT content (Figure 4(a)). Compared with the tensile modulus of S/P composite without CNTs (2.65 ± 0.17 GPa), the tensile modulus of 4.5 C/S/P composite (5.17 ± 1.05 GPa) increased by 95.1% when the CNT content was 4.5 wt% (Figure 4(b)), indicating that the rigid filler of CNTs played a key role in enhancing the mechanical properties of the SCF/PEEK composites. The addition of rigid nano-fillers increased the deformation resistance of the composites at the onset of tensile testing. However, the tensile strength of the composites showed a trend of initial decrease and then increase as the content of CNTs increased, which is inconsistent with the results of the tensile modulus. When the CNT content was 1.0 wt%, the tensile strength of C/S/P was the lowest (62.32 ± 1.81 MPa), which was 15.9% lower than that of S/P (74.14 ± 2.90 MPa). As the CNT content continued to increase, the tensile strength of the C/S/P composites showed a further upward trend. The tensile strength of 4.5 C/S/P reached 73.76 ± 5.23 MPa, which was close to that of the control S/P. The reasons for the trend of decreasing and then increasing tensile strength with increasing CNT content were analyzed as follows. Limited by the mixing method and process of CNTs, the addition of CNTs into the SCF/PEEK composites may cause defects such as agglomeration and uneven distribution. These defects not only affected the reinforcement effect of CNTs on composites but also led to the generation of additional defects, such as pores, during the printing of composite materials. These defects became stress concentration points during tensile testing, leading to the premature failure of the samples and a subsequent reduction in tensile strength. However, the tensile modulus trend and stress–strain curves revealed that the addition of CNTs did have a reinforcing effect on the mechanical properties of the SCF/PEEK composites. Consequently, the fracture tensile strength of the C/S/P samples with varying CNT contents resulted from the interplay between the strengthening of mechanical properties and the stress concentration caused by the introduced defects. To validate this explanation, we conducted further experiments, the results of which are discussed in the following section.

The mechanical properties of composites depend not only on the matrix and reinforcing phases but also on the interfacial strength of the composite.³¹ The interfacial strength between SCF and PEEK was evaluated using the ILSS test. Figure 5 demonstrates the effect of different content of CNTs on the SCF/PEEK interface strength. The ILSS results were similar to the tensile strength results, showing a tendency to decrease and then increase with increasing CNT content. The lowest ILSS of C/S/P was obtained at a CNT content of 1.0 wt% with a value of 5.66 ± 0.54 MPa, and was reduced by 36 ± 0.39% compared to pure S/P. This result may be related to the CNT agglomeration and increased defects at the interface.³² Similarly, the interfacial bonding strength of C/S/P composites was enhanced by a further increase in the CNT content. This may indicate that when the CNT content further increased, the agglomeration of nano-fillers was no longer the main factor affecting the strength of the interlaminar interface.

To further explore the influence mechanism of CNTs on the mechanical properties of the SCF/PEEK composites in the additive manufacturing process, the fracture morphology of the composites after tensile testing was investigated using SEM. Figure 6 shows the morphology of the fracture surface of the samples after tensile fracture. The introduction of CNTs exacerbated the delamination between the printed layers (Figure 6(a)), which may have led to the reduction in the tensile strength of the C/S/P composites. The fracture surfaces of all composites exhibited varying degrees of short fiber pullout. The size of the holes left after fiber pullout was close to the fiber diameter.¹⁷ Furthermore, the surface of the fibers pulled out was not surrounded or bound by PEEK resin (Figure 6(b)). Therefore, the addition of CNTs to the SCF/PEEK composites did not enhance interfacial adhesion. This may be related to the weak van der Waals forces between CNTs and SCF and PEEK.^33,34 Meanwhile, when CNTs were added to the SCF/PEEK composites, the internal defects, such as pores, increased in samples, which may be the reason why the tensile strength of C/S/P was lower than that of the control S/P (Figure 6(b) and Figure 7(a)).³⁵ When the CNT content was 0.5 and 1.0 wt%, and the pore size was 16.4 ± 8.0 μm and 21.1 ± 10.4, respectively, the pore size inside the C/S/P composites enlarged with the increase in CNT content. This was relevant to the CNT agglomeration which exacerbated pore formation in the composites during the printing process.³⁶ However, when the nano-filler content was further increased, the pore defects inside the composites did not show further aggravation. Instead, the pore size of the 4.5 C/S/P composites (18.7 ± 7.4) was smaller than that of the 3.0 C/S/P composites (21.7 ± 9.4) (Figure 6(b)). The occurrence of this phenomenon remained unclear. Figure 6(c) shows that even when the CNT content was lower (0.5 wt%), CNTs agglomerated inside the composites. A previous study¹⁴ reported that the agglomeration of nano-fillers exacerbated the internal defects in composites, causing stress concentration, macro-cracks, and ultimately composites failure. Therefore, compared with S/P composites, the main reasons for the decrease in the tensile strength of C/S/P composites could be the agglomeration of CNTs, the increase in pore defects, and the decrease in interlaminar adhesion.

The porosity of the samples is shown in Figure 7(b). The porosity of S/P composites was lower than that of the C/S/P composites. In addition, the porosity of the C/S/P samples reached the maximum value when the CNT content was 1.0%, which corresponded to the results of tensile and interlaminar shear strengths of 1.0 C/S/P. However, when the content of CNTs was further increased, the porosity of the C/S/P composites exhibited a decreasing trend, whereas the porosity was still higher than that of the S/P composites. Therefore, we speculated that the increase in tensile and interlaminar shear strengths of 3.0 C/S/P and 4.5 C/S/P compared to 1.0 C/S/P may be attributed to a decrease in porosity in the composites.

Figure 7(c) presents DSC curves at various CNTs content for C/S/P composites. The endothermic peak for pure SCF/PEEK composite at 345.7°C can be related to the melting temperature (Tm) of PEEK, and the introduction of CNTs does not significantly change Tm and the enthalpy of ΔHm, which is consistent with the observations reported in literature.³⁷ The crystallinity is calculated and tabulated in Table 2. The crystallinity of pure SCF/PEEK is 41.78%, already at a relatively high region, indicating that the addition of SCF already provided effective nucleation sites and facilitated the crystallization of PEEK.³⁷ Moreover, the crystallinity of C/S/P composites moderately increases with the content of CNT increasing (Xc-0.5 C/S/p = 44.10%, Xc-1.0 C/S/p = 46.53%, Xc-3.0 C/S/p = 46.55%, Xc-4.0 C/S/p = 48.71%), indicating the addition of CNTs are beneficial to the crystallization of PEEK,³⁸ in agreement with the trend of tensile modulus of C/S/P composites.

Table 2.

Mechanical properties and porosity of the C/S/P composites.

SampleName	Tensile modulus (GPa)	Tensile strength (MPa)	Interlaminar shear strength (MPa)	Theoretical density (g/cm³)	Porosity of sample (%)	Crystallinity (%)
S/P	2.65 ± 0.11	74.14 ± 2.90	8.88 ± 0.32	1.335	12.66 ± 1.25	41.78
0.5 C/S/P	3.04 ± 0.30	64.64 ± 0.51	6.20 ± 0.65	1.338	16.74 ± 1.89	44.10
1.0 C/S/P	3.73 ± 0.08	62.32 ± 1.81	5.66 ± 0.54	1.341	21.88 ± 3.20	46.53
3.0 C/S/P	3.97 ± 0.06	66.64 ± 1.47	7.89 ± 0.24	1.351	21.32 ± 3.57	46.55
4.5 C/S/P	5.17 ± 1.05	73.76 ± 5.23	8.21 ± 1.16	1.359	17.74 ± 2.12	48.71

In summary, we have observed two effects resulting from the addition of CNTs. Firstly, the addition of CNTs could enhance the mechanical performance of the samples, which can be evident by the results of tensile modulus, and the strengthening effect of CNTs on mechanical properties is positively correlated with its content. The second effect is the introduction of defects caused by CNTs, such as pores and agglomerations. These defects lead to stress concentration areas, consequently reducing the tensile strength. These two effects are interrelated; therefore, the ultimate mechanical performance of the samples is a comprehensive outcome of the interaction between these effects. When the filler content is low, the enhancing effect on mechanical properties is weak whilst defects effect is relatively significant, leading to a noticeable decrease in strength. As the CNTs content increases, despite the continued existence of defects, the significant enhancement in mechanical performance results in an overall improvement in the composite’s properties.

Conclusion

The mechanical properties of 3D printed SCF/PEEK composites with varying content of CNTs were studied. The results showed that the introduction of CNTs could effectively enhance the mechanical properties of SCF/PEEK, as the tensile modulus increased from 2.65 ± 0.17 GPa to 5.17 ± 1.05 GPa, representing a 95.1% increase. However, the tensile strength and interlaminar shear strength showed an initial decreasing and then increasing trend with the increasing CNT content from 0.5 wt% to 4.5 wt%. Morphological and physical analysis were further investigated to reveal the underlying mechanisms. Albeit the CNTs could improve the mechanical properties of the printed SCF/PEEK, agglomerations and defects were also induced with the introduction of CNTs. Therefore, the ultimate mechanical properties of the composites with varying CNT contents resulted from the interplay between the reinforcing effect of the nanoparticles and the stress concentration caused by the introduced defects.

Footnotes

Author contributions

Wenzhe Song: Conceptualization, Formal analysis, Methodology, Writing—original draft, Writing—review and editing. Xuejun Ding: Formal analysis, Methodology. Congzhe Fan: Writing—review and editing. Jinghua Zheng: Writing—review and editing. Jingxuan Wang: Formal analysis, Methodology. Yiwei Chen: Project administration, Writing—Review and Editing. Zhongde Shan: Supervision. Chaozhong Chen and Congfa Zhang: Funding acquisition, Project administration.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Fundamental Research Funds for the Central Universities (NS2021044), the Natural Science Foundation of Jiangsu (BK20210314 & BK20220895 & BK20230888 & BK20243056), the National Natural Science Foundation of China (52205383), the Advanced Civil Aerospace Technology Program (D020303), the Postdoctoral Science Foundation of China (2021M691568 & 2024M754120), State Key Laboratory of Materials Processing and Die & Mould Technology and Shanghai Spaceflight Precision Machinery Institute Technology Innovation Fund.

ORCID iDs

Wenzhe Song

Congze Fan

Data availability statement

The data that support the funding of this study are available from the corresponding author or initial author, upon reasonable request.*

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