BIOLOX delta Ceramic Design Rationale

Hip Product Group

Culmination of over 30 years of ceramics research

BIOLOX® delta represents the most recent advance in the evolution of alumina ceramic for orthopedic applications—providing the well-known advantages of previous generation alumina ceramics along with innovative toughening mechanisms. (Table 1)

Combines strength and toughness

As a composite of alumina and zirconia, BIOLOX delta combines the excellent hardness and wear properties of alumina with the superior fracture toughness properties associated with zirconia. [1,2]

Table 1: Improvements over 3 generations of alumina ceramics [3]
  BIOLOX BIOLOX forte BIOLOX delta
Year introduced 1974 1995 2004
4-point bending strength
(MPa)
500 (45) 631 (38) 1384 (67)
Fracture toughness K10
(MPam1/2)
3.0 (0.45) 3.2 (0.4) 6.5 (0.3)
Hardness HV1
(GPa)
20 20 19


Optimized composition and microstructure

Material scientists optimized the chemical composition and microstructure (Figure 1) to design a material with excellent wear and mechanical properties. [1,2]

Figure 1: SEM of BIOLOX delta microstructure

BIOLOX delta microstructure

Toughening Mechanisms

The toughness of a material refers to its ability to resist the propagation of cracks. BIOLOX delta utilizes two strategies to improve toughness [2]:

  • Crack deflection: The elongated platelet grains deflect and halt microcracks.
  • Transformation toughening: Zirconia nanoparticles increase slightly in volume when triggered by nearby microcrack, providing an obstacle to crack propagation.

† BIOLOX delta is a registered trademark of Cerasiv GmbH Innovatives Keramick-Engineering and CeramTec AG Innovative Ceramic Engineering.

  1. Masson B. Emergence of the alumina matrix composite in total hip arthroplasty. International Orthopaedics 2009; 33(2): 359-363.
  2. Kuntz M, Shneider N, Heros R. Controlled Zirconia Phase Transformation in BIOLOX® delta — a Feature of Safety. In Bioceramics and Alternative Bearings in Joint Arthroplasty. 10th BIOLOX Symposium Proceedings. (eds. D’Antonio JA, Dietrich M) Steinkopff Verlag, Darmstadt, 2005; 79-83.
  3. CermTec AG. BIOLOX delta nanocomposite for arthroplasty The fourth generation of Ceramics: Scientific information and performance data. [Brochure] Retrieved from mt_biolox_delta_en.pdf.