Effect of Sintering Temperature on Some Physical And Mechanical Properties of Fabricated Hydroxyapatite Used For Hard Tissue Healing


This work focuses on studying the role of drying and calcination onstiochiometry and crystallinity of deposited HA. Also, studying the effect of sinteringtemperature on phases generated, physical and mechanical properties of sintered HApowder compact at a range of (800-1200) ˚C.Both Ca/P ratio and crystallinity were increased after calcination, where the Ca/Pratio raised from 1.7 to 1.9 and the height of Hydroxyapatite peak intensity was alsoincreased .Secondary phases also appeared.X-ray diffraction patterns and electrical microscopic pictures of polished surfacesof the Hydroxyapatite compact after sintering had revealed the process ofdensification and crystallization of Hydroxyapatite . The increase of sinteringtemperature leads to grain growth, while surface cracking and other defects becamelower i.e. porosity and surface voids.Both hardness and fracture strength were increased for samples sintered at hightemperatures where they reached their maximum values at sintering temperature(1200)ºC .The maximum linear shrinkage was 20% at sintering temperature 1200ºC.The maximum bulk density was (2.173) g/cm3 at sintering temperature of 1200ºCand the maximum apparent density was (2.58) g/cm3 at sintering temperature 900ºC.The maximum apparent and open porosities were 47.136% and 47.058% respectivelyat sintering temperature 900ºC. The maximum water absorption was 39.13% atsintering temperature 800ºC.