On the characteristics of acetylene-oxygen flames used in dental casting

In a specially designed casting and gas measuring equipment the melting process used in dentistry for Co-Cr alloys using the acetylene-oxygen flame as heating source were investigated. The influence of different gas mixtures in the flame and different crucible temperatures on: 1. The temperature increase in the alloy. 2. The melting time of the alloy. 3. The temperature in the alloy when all the metal has melted and forms the spherical shape--the Bull's eye stage. 4. The melting time when different amounts of alloy were used in the melt. 5. The temperature increase and melting time when flux are used. 6. Different distances between the torch and the alloy. were studied. The results showed that the melting process is mainly governed by the heating effect and the chemical character of the parts of the flame used and also on the initial temperature of the crucible.