Sharing on the fatigue properties of medical implant grade AKSOPEEK® materials

PEEK polyetheretherketone

PEEK (polyetheretherketone) is a member of special engineering plastics. It is widely used in industrial production due to its light weight, high strength, wear resistance, corrosion resistance, high temperature resistance and other characteristics. PEEK and its modified materials are also known as the new generation of ideal orthopedic implant materials after titanium alloys because of its good biocompatibility and elastic modulus similar to that of human bones.



PEEK fatigue properties

When materials, parts and components are subjected to cyclic loading, local damage occurs at one or some points, and cracks are formed after a certain number of cycles, or the cracks are further extended until they are completely broken. Fatigue performance refers to the ability of a material to resist fatigue fatigue [1].

Today, let’s talk about the fatigue properties of PEEK. Using the YY/T 1503 (ASTM F382) test standard, the AKSOPEEK® LCF plate (thickness 4mm) was subjected to bending fatigue testing at a load of 800N, a frequency of 5Hz, and a test number of 1.2 million times. The performance was comparable to that of titanium alloy and better than pure titanium.

In order to further compare the fatigue strength of AKSOPEEK® LCF and titanium alloy, we selected four groups of 2mm thick titanium alloy Ti-6Aal-4V) and AKSOPEEK® LCF splines for fatigue testing under 382N conditions. The four groups of AKSOPEEK® LCF did not fail after 1 million fatigue tests, while the titanium alloy failed due to fatigue at 73,000, 82,000, 79,000, and 92,000 times, respectively.


The AKSOPEEK® Natural intervertebral fusion cage (H: 6.3mm) was subjected to compression fatigue testing using the YY/T 0959 (ASTM F2077) test standard at a load of 2000/4000N, a frequency of 5Hz, and a test number of 5 million times. No failure due to fatigue occurred. Static testing before and after fatigue also showed no strength reduction, and this model of fusion cage only showed compression yield at 12000N.


Deeply engaged in sports medicine

The company has established a special team to cooperate with customers in the medical industry to be responsible for the research and development, production and sales of medical polymer materials and products such as medical PEEK, PPSU, LCF/PEEK thermoplastic composites.

In 2021, in order to meet the development needs of domestic sports medicine, the company actively cooperated with major domestic medical institutions to develop sports medicine molds, with the following advantages:

(1) Many years of experience in PEEK injection molding;

(2) Complete sports medicine development process;

(3) The same brand and model of micro injection molding machines can achieve seamless switching with friendly companies;

(4) The complete after-sales service system is recognized by major domestic medical institutions.


Based on the present, looking to the future. The implantable PEEK project was officially launched in 2021 and is in the second round of inspection. The results of the inspection will be announced around August 2022. In order to better standardize implantable PEEK, a new implantable AKSOPEEK series of grades will be added.

1) AKSOPEEK® Natural: Implantable PEEK pure material;

2) AKSOPEEK® HA: Implantable PEEK material with hydroxyapatite to improve biocompatibility;

3) AKSOPEEK® CF: Implantable PEEK material with chopped carbon fiber;

4) AKSOPEEK® LCF: Implantable PEEK material with continuous carbon fiber;


Note: [1]. Fatigue, Baidu Encyclopedia.