Abstract:

Objective　The purpose of this study was to compare the compressive strength of phosphate-bonded invest- ments.Methods　The three sorts of investmentswere mixed accordingtomanufacturer′s recommendation before poured in the mol- ds. After heated up to 900℃, every sample was mounted on a universal experimental machine to test its compressive strength in ambient.Results　Significant differences were found between the four groups(P<0·01).Conclusion　From the data above it is concluded that the compressive strength of X-20 Chrome Investment mixed with the special liquid was the highest.

Key words: investment materials, compressive strength, phosphate