IADR Abstract Archives
Computer Simulation on Development of High Performance Phosphate-bonded Investment
Methods: Solid densities of as-received powders, set and burnout compacts were measured for four kinds of commercial phosphate-bonded investments (conventional and quick-heating type) using gas pycnometer. Porosities of the set and the burnout compacts were calculated from the measured data. These data were confirmed by theoretical quantitative computation for set and heating reaction of phosphate-bonded investment under the assumption.
Results: The measured data were well agreed with the developed numerical simulation as shown in Table. Effect of liquid/powder ratio on porosity of the investment compacts and rate of dehydration from hardening water-powder mixture were estimated from the simulation. Setting expansion was estimated from theoretical computed porosity and measured porosity for dry setting compacts.
Table Measured solid density and porosity of the compacts after hardened and burnout. Here, values in parentheses are simulated results.
Investment |
W/P |
Dry set compact |
Burnout compact |
||
Density (g/cm3) |
Porosity (%) |
Density (g/cm3) |
Porosity (%) |
||
A |
0.22 |
2.321 |
24.0 (24.9) |
2.681(2.648) |
42.8(41.9) |
B |
0.22 |
2.434 |
27.3(26.4) |
2.810(2.794) |
43.6(42.9) |
C |
0.24 |
2.353 |
32.2(31.2) |
2.599(2.623) |
43.1(45.6) |
D |
0.22 |
2.452 |
31.7(29.7) |
2.750(2.722) |
43.5(43.4) |
Conclusions: The developed simulation procedure for the set and burnout phosphate-bonded investment can be applied to the compositional design of the investment with high performance during its processing.