Strengthening of a Pd-free high gold dental alloy for porcelain bonding by a pre-firing heat treatment.
OBJECTIVE
The purpose of the present investigation was to report a Pd-free high gold alloy for porcelain bonding based on the ternary system of Au-Pt-Zn with a nominal composition of 86Au-11Pt-1.5Zn-0.5In-0.7Rh-0.2Fe-0.1Ir (wt.%). Emphasis was put on the effect of a pre-firing heat treatment on the mechanical properties of the alloy.


METHODS
The strengthening effect of the pre-firing heat treatment was investigated by means of hardness measurement, tensile testing, X-ray diffraction, optical microscopy and scanning electron microscopy.


RESULTS
Experimental results showed that both the hardness and tensile strength of the alloy can be significantly improved after heat treatment at the temperature of 980 degrees C for 15 min. The strengthening could be attributed to homogenization of microstructure and alloying elements and precipitation of new fine particles.


CONCLUSIONS
The cast framework of the present new Pd-free alloy could be heat treated before actual firing, and this would improve the processing properties of the alloy during firing.
Liu
W B
WB
School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, PR China.
Wang
J N
JN
D003722:Dental Alloys / Q000737:chemistry*; D001840:Dental Bonding; D003735:Dental Casting Technique; D003776:Dental Porcelain / Q000737:chemistry*; D004577:Electron Probe Microanalysis; D006047:Gold Alloys / Q000737:chemistry*; D006244:Hardness; D006358:Hot Temperature; D006801:Humans; D007204:Indium / Q000737:chemistry; D007495:Iridium / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D008422:Materials Testing; D008853:Microscopy; D008855:Microscopy, Electron, Scanning; D010165:Palladium; D010984:Platinum / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry; D013314:Stress, Mechanical; D013718:Tensile Strength; D013997:Time Factors; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry
D003722:Dental Alloys; D006047:Gold Alloys; D007204:Indium; D003776:Dental Porcelain; D007495:Iridium; D010984:Platinum; D010165:Palladium; D012238:Rhodium; D007501:Iron; D015032:Zinc