Effect of sintering parameters on physical and mechanical properties of powder injection moulded stainless steel-hydroxyapatite composite

PLoS One. 2018 Oct 25;13(10):e0206247. doi: 10.1371/journal.pone.0206247. eCollection 2018.

Abstract

The combination of metallic bio-inert material, stainless-steel 316L (SS316L) and a bio-active material, hydroxyapatite (HA) can produce a composite which has superior properties for orthopaedic applications. The main objective of this study is to investigate the effects of sintering temperature and holding time on the physical and mechanical properties of the sintered part. 50wt.% SS316L and 50wt.% HA were mixed with a binder system of palm stearin (PS) and polyethylene (PE) at 61 vol.% powder loading. Rheological properties show a pseudo-plastic behaviour of the feedstock, where viscosity decreases with increasing shear rate. The feedstock was injection moulded into a tensile bar shape while thermal debinding was carried out at 320°C and 500°C. The brown parts were sintered at 1000, 1100, 1200 and 1300°C, with three different sintering times of 1, 3 and 5 hours in the furnace. It was found that the highest sintered density measured was 95.61% of the theoretical density. In addition, the highest hardness and Young's modulus measured were 150.45 HV and 52.61 GPa respectively, which are higher than those of human bone. The lowest percentage of carbon content was 0.022wt.% given by the sample sintered at 1300°C for 1 hour. Therefore, SS316L/HA composite with good mechanical and physical properties was successfully produced through the PIM process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Coated Materials, Biocompatible / chemical synthesis*
  • Coated Materials, Biocompatible / chemistry*
  • Durapatite / chemistry*
  • Elastic Modulus
  • Electroplating / methods
  • Hardness
  • Humans
  • Injections
  • Materials Testing*
  • Mechanical Phenomena
  • Metallurgy / methods
  • Physical Phenomena
  • Powders / chemistry
  • Stainless Steel / chemistry*
  • Surface Properties
  • Temperature

Substances

  • Coated Materials, Biocompatible
  • Powders
  • Stainless Steel
  • Durapatite

Grants and funding

This work was supported by Trans-disciplinary Research Grant Scheme from Ministry of Higher Education of Malaysia (MoHE). Project code: TRGS/2/2014/UKM/02/4/1. Fund received by Assoc. Prof. Ir. Dr. Abu Bakar Sulong, and Dana Impak Perdana from Universiti Kebangsaan Malaysia. Project code: DIP/2016/009. Fund received by Prof. Dr. Norhamidi Muhamad. Both funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.