In the fields of aerospace, energy and chemical engineering, due to the harsh use environment (such as high temperature, high pressure, corrosion), such as aircraft engines, they are currently developing in the direction of high thrust, low energy consumption, and long service life, thus placing higher requirements on material performance. In addition to considering the high-temperature mechanical properties of the material, the creep of the material also needs to be considered. Creep refers to the phenomenon that the strain of the material increases with time under a certain temperature and a small constant stress. In other words, the better the creep resistance, the smaller the deformation under a certain stress, and the product will not crack due to deformation, so the service life is longer.

Creep performance test

PEEK (polyetheretherketone) is a semi-crystalline thermoplastic special engineering plastic with excellent mechanical properties, corrosion resistance, wear resistance, creep resistance and other characteristics. Pure PEEK still maintains sufficient mechanical properties at 160 ℃ for a long time. After fiber modification, the use temperature can reach 260 ℃. In this paper, the ISO 899-1 test standard is used to conduct tensile creep test on it. The test is 5 hours, and the results are shown in the figure below.

Figure 1 Creep curve of materials

First, the creep of materials usually goes through three stages (as shown in Figure 1): Stage I: unstable stage; Stage II: stable stage; Stage III: accelerated and destructive stage. Therefore, the working section of the material cannot exceed the stable stage. In other words, the longer the stable stage, the longer the service life of the material.

Figure 2 PEEK 5600G room temperature tensile creep under different stresses

Secondly, from Figure 2 we can find that the strain gradually increases with the increase of stress, while the deformation of pure PEEK even under a stress of 60 MPa hardly increases during the test time, indicating that it has good creep resistance.

In addition to stress, temperature also affects the creep properties of the material. The higher the test temperature, the more obvious the creep.

The company is a professional production service provider that can provide innovative PEEK material applications from polymerization, molding to finished products. The company is committed to the research of the basic properties of PEEK materials, and has established long-term cooperation mechanisms with universities such as Jilin University, Donghua University, and Changzhou University. It has successively obtained qualifications such as “National High-tech Enterprise”, “Changzhou Special Engineering Plastics Engineering Technology Research Center”, and “Jiangsu Postgraduate Workstation”, and has contributed its own strength to the domestic PEEK industry.