Transmission electron microscopic investigation of a Pd–Ag–In–Sn dental alloy

• Published in: Biomaterials 2003-05, Vol.24 (10), p.1705-1712
• Main Authors: Guo, W.H, Brantley, W.A, Clark, W.A.T, Monaghan, P, Mills, M.J
• Format: Article
• Language: English
• Subjects: Dental Alloys - chemistry; Dental Restoration, Permanent; Discontinuous precipitation; Eutectic; Hot Temperature; Humans; In Vitro Techniques; Indium - chemistry; Materials Testing; Metal Ceramic Alloys - chemistry; Microscopy, Electron; Microstructure; Palladium - chemistry; Pd–Ag dental alloy; Silver - chemistry; Surface Properties; Tin - chemistry; Transmission electron microscopy
• ISSN: 0142-9612; 1878-5905
• DOI: 10.1016/S0142-9612(02)00564-1

With the price volatility of palladium, there has been renewed interest in palladium–silver alloys for metal-ceramic restorations in dentistry. The microstructures of a popular Pd–Ag dental alloy were investigated in the as-cast and simulated porcelain-firing heat-treated conditions, using transmission electron microscopy. In the as-cast condition, the microstructure was strongly influenced by microsegregation, and contained the face-centered cubic Pd solid solution matrix, a eutectic structure with lattice parameters that varied for the two phases, and a face-centered tetragonal (fct) precipitate. After heat treatment, the lattice parameters for the two phases in the eutectic structure were uniform, and discontinuous precipitates with {0 1 1} matrix habit planes and dislocations appeared in the matrix. An unusual nanostructured constituent was found in the fct set of eutectic lamellae in the heat-treated alloys.