Polytetrafluoroethylene (PTFE) is a polymeric material with excellent self-lubricating properties. In this study, in order to improve the wear resistance of PTFE, the PTFE matrix was filled with soft-phase polyetheretherketone (PEEK) particles and hard-phase nano-ZrO₂ particles in varying volume ratios. A linear reciprocating friction tester was used to test the tribological properties of the PTFE composites. Optical microscopy (OM) and scanning electron microscopy (SEM) were utilized to observe the formation and evolution of the transfer film on the surface of the counterpart metal during the friction process. Molecular dynamics simulation software (Materials Studio MS) was used to simulate and analyze the frictional behavior between the molecular structures of PTFE composites and the counterpart iron atoms on a microscopic scale. The results showed that the uniformity and firmness of the transfer film had an important influence on the wear resistance of the material. PEEK and ZrO₂ nanoparticles were able to improve the firmness and formation rate of the transfer film, respectively, resulting in significant improvement in the wear resistance of PTFE (volume wear rate reduced from 7.7 × 10⁻⁴ mm³/Nm for pure PTFE to 1.76 × 10⁻⁶ mm³/Nm for nano-ZrO₂/PEEK/PTFE). Molecular dynamics simulations revealed that the poor wear resistance of PTFE was due to significant interlayer slippage within its molecular chains. PEEK molecular chains could effectively adsorb PTFE molecular chains and formed a strong bond. ZrO₂ nanoparticles also contributed to the overall stability of the PTFE matrix. Both soft and hard fillers significantly inhibited interlayer slippage between PTFE molecular chains, enhancing the shear deformation resistance of the material and thus improving the wear resistance of PTFE composites.

The materials tribology community has identified that the transfer film attached to the surface of the counterpart metal during the friction process is not only closely related to the filler modification material but also a key factor affecting the tribological properties of polymer composites; however, there is a lack of feasible methods to quantify the characteristics of the transfer film. In this study, Nano-ZrO₂ and polyetheretherketone (PEEK) were filled into a PTFE matrix in order to enhance the wear resistance of polytetrafluoroethylene (PTFE). The tribological properties of the modified PTFE composites were tested using a linear reciprocating friction and wear tester, and the entire friction experiment was designed in seven separate stages. Morphological features were extracted and analyzed from photographs of the transfer film acquired by optical microscopy at each friction stage using an image processing program. The thickness and roughness of the transfer film sections were measured using a non-contact profilometer. Abrasive debris were collected, and their morphological features were observed with an electron microscope. The results showed that the synergistic addition of soft PEEK and hard Nano-ZrO₂ particles effectively inhibited interlayer slippage between PTFE molecular chains, dramatically reducing the size and yield of abrasive debris, and facilitated the improvement of the thickness and firmness of the transfer film, which significantly enhanced the wear resistance of the PTFE composites (the lowest volumetric wear rate for Nano-ZrO₂/PEEK/PTFE was only 1.76 × 10⁻⁴ mm³/Nm). Quantitative analyses of the morphological characteristics of the transfer films revealed that the coverage and roundness of the transfer films gradually increase with the friction stroke, while the aspect ratio and texture entropy subsequently decrease gradually. The coverage, area, mean, third-order moments, and consistency of the transfer film strongly correlated with the volumetric wear rate (correlation coefficient |r| > 0.9).

In this paper, the tribological properties of polytetrafluoroethylene (PTFE) composites filled with Nano-ZrO₂ and polyetheretherketone (PEEK) particles were tested for sliding friction against a counterpart metal (ASTM 1045 steel) using a linear reciprocating friction and wear experimental machine. Data on tribological performance and optical images of the transfer film were obtained at various friction stages for the material. MATLAB software was employed to develop quantitative analysis procedures for the morphological characteristics of the transfer film. The program enables image enhancement and morphological processing of transfer film images, then identifies, extracts, and quantifies the geometric and textural properties of the transfer film as a foundation for analyzing the variation of the characteristics and their relationship to the tribological properties of the material. The results demonstrated that the geometric, morphological, and textural characteristics of the transfer film were dynamically developing during the friction process, with noticeable differences between various friction stages and a significant impact on the tribological properties of the material. Quantitative analysis revealed a good correlation between the trends of some morphological and textural characteristics (the coverage, area, diameter, roundness, consistency, and texture entropy) of the transfer film and the wear resistance of the PTFE composite. Therefore, these morphological and textural characteristics can thus be used to quantify the transfer film quality and utilized as an indirect indicator of the tribological properties of the material.

Straw checkerboard sand barriers play a critical role in wind erosion control and dune stabilization. However, manual installation remains predominant, leading to low efficiency and inconsistent quality. To address this, a compact integrated machine was developed for straw checkerboard laying and pressing using rice straw. The design emphasizes the coordinated function of the straw distribution and pressing systems. Physical parameters of rice straw—average bundle length (<120 cm), repose angle (20.95°), and elastic modulus (1.65 MPa)—were measured to guide structural design. A 3D model of the machine and a multibody dynamic simulation of the distribution system were conducted to validate the mechanical configuration. Field trials were performed using straw mass per metre and average layer thickness as evaluation metrics. Single- and multi-factor experiments combined with response surface methodology yielded optimal parameters: conveyor shaft speed of 230 r/min, crankshaft speed of 227 r/min, and a third-stage tooth height of 0.03 m. Field tests in desert environments confirmed straw output of 0.2–0.4 kg/m, layer thickness of 2–3 cm, burial depth of 14.3–19.5 cm, and exposed height of 19.8–39.5 cm. Results meet quality specifications for barrier construction, demonstrating the machine’s strong applicability and potential for engineering deployment in desertification control.