Mechanical properties of hot pressed CoCrMo alloy compacts for biomedical applications. (15th October 2015)

• Record Type: Journal Article
• Authors: Henriques, B.; Bagheri, A.; Gasik, M.; Souza, J.C.M.; Carvalho, O.; Silva, F.S.; Nascimento, R.M.
• Is Part Of: Materials & design. Volume 83(2016:Jul.)
• Page Start: 829
• Page End: 834
• Publication Date: 2015-10-15
• Subjects: CoCrMo alloy -- Hot pressing -- Mechanical properties -- Biomedical applications; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2015.06.069
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: CoCrMo hot pressing conditions were evaluated and the influence on mechanical properties were determined. At 900 °C compacts showed high porosity, low mechanical strength, low hardness and low Young's modulus. At 1000 °C and 1100 °C compacts showed similar mechanical strength, porosity and Young's moduli. Higher hardness values were registered for 1000 °C compacts when compared to those hot pressed at 1100 °C. The 900 °C compacts exhibited brittle behavior while 1000 °C and 1100 °C compacts exhibited ductile behavior. Abstract: This study aimed at investigating the influence of the processing conditions on the mechanical properties of hot pressed compacts of a CoCrMo biomedical alloy. Several hot pressed CoCrMo compacts were processed in vacuum (10 −2 mbar), at a pressure of 60 MPa with different temperatures (900 °C, 1000 °C and 1100 °C) and different times (10 min, 30 min and 60 min). Compacts were examined by SEM/EDS. The transverse rupture strength, Young's Moduli and hardness were determined. The fracture surface of compacts were also examined. The compacts hot pressed at 900 °C exhibited lower TRS than those processed at 1000 °C and 1100 °C, which showed similar strength values, regardless the sintering time. The 900 °C compacts showed also lower YM and higher porosity. Lower hardness values were registered for 900 °C compacts while 1000 °C compacts exhibited the highest values. The fracture surface analyses revealed fragile fracture for 900 °C compacts (10 min and 30 min) and 1000 °C (10 min). The remaining compacts exhibited ductile fracture. A full characterization of the mechanical properties of hot pressed CoCrMo compacts has been made and the selection of the processing parameters according to the desired mechanical properties is now possible.