Effects of wire EDM on the microstructure of P/M titanium samples/Utjecaj obrade erozimatom na mikrostrukturu povrsine titanija dobivenu metalurgijom praha

• Published in: Acta stomatologica croatica 2014-12, Vol.48 (4), p.285
• Main Authors: Viskic, Josko, Schauperl, Zdravko, Catic, Amir, Balog, Ma, Krizik, Peter, Grzeta, Biserka, Popovic, Jasminka, Ortolan, Sladana Milardovic, Mehulic, Ketij
• Format: Article
• Language: English
• Subjects: Dental materials; Health aspects; Machining; Measurement; Mechanical properties; Strength (Materials); Titanium
• ISSN: 0001-7019
• DOI: 10.15644/asc48/4/6

Purpose: Commercially pure titanium (CP Ti) has been recognized in dentistry for its biocompatibility, good mechanical properties and corrosion resistance. Conventional manufacturing processes can affect surface quality and result in poor bonding of dental ceramics to CP Ti. This is why powder metallurgy (P/M) and wire electro-discharge machining (WEDM) are being introduced in the manufacturing process. The aim of this study was to evaluate the effect of WEDM on the surface composition and microstructure of P/M CP Ti samples produced for bond strength testing according to ISO 9693. Materials and methods: Eight samples of P/M CP Ti, dimensions according to ISO 9693, were made using WEDM and divided in two groups (untreated and grinded). Microanalyses of chemical composition and microstructure of both groups were made using SEM, EDS and XDR. Results: SEM and EDS analysis of untreated samples showed a thin layer on surfaces with fractures in it. Grinded samples showed homogenous structure with no layer and no fractures. XDR analysis showed high level of oxides on the surface of untreated samples, while after grinding only pure a-phase was found. Conclusion: WEDM is a suitable method of sample production for ISO 9693 if accompanied by grinding with silicon carbide papers P320-P4000. Key words Titanium, WEDM, bond strength, powder metallurgy, Surface Properties Komercijalno cisti titanij (CP Ti) se koristi u dentalnoj medicini zbog biokompatibilnosti, dobrih mehanickih svojstava i otpornosti na koroziju. Konvencionalni proizvodni procesi izrade takvog titanija mogu utjecati na kvalitetu povrsine uzoraka i rezultirati slabim vezanjem CP Ti s dentalnom keramikom. Zato se uvode nove tehnologije proizvodnje titanija, primjerice metalurgija praha i oblikovanje na erozimatu s zicom (WEDM). Svrha ovog istrazivanja jest odrediti utjecaj WEDM-a na povrsinu uzoraka P/M CP Ti proizvedenih za ispitivanje vezne cvrstoce prema normi ISO 9693. Materijali i metode: Osam uzoraka P/M CP Ti dimenzija prema normi ISO 9693 proizvedeno je koristenjem WEDM-a i podijeljeno u dvije grupe--u neobradene i brusene. Povrsine obje grupe uzoraka analizirane su metodama SEM, EDS i XDR. Rezultati: Analize neobradenih uzoraka metodama SEM i EDS pokazuju tanki sloj razlicitog sastava i frakture. Bruseni uzorci imaju homogenu strukturu bez fraktura. Analiza metodom XDR pokazuje visoku koncentraciju titanijevih oksida na povrsini neobradenih uzoraka, a nakon brusenja dobivena je samo cista a-faza.