T1 Test to check molten metal flow and trial production
Metalmold temperature approximately 95°C
Temperatureduring pouring about 1010°C
Molten metal flow is good
Moltenmetal is filled all the way up to up-hill part for degassing.
Whenthe product was made with a plan with fast molten metal flow supplied toproduct parts, overall run was sufficient.
Themetal mold plan has a large influence on Permanent mold casting.
Adefect was found in trial production caused by shrinkage in the part sandwichedby the core, which is the part that solidifies last.
We believe the defect can be resolved by using adifferent gate thickness and position.
Thevarying components due to Zn depletion in molten metal appeared to causechanges in the flow of molten metal.
T2 Teeter mold test
Result: Good It can be used for Permanent mold casting
Internalshrinkage showed a smooth surface.
Thedeepest part of shrinkage did not contain any rough textured surface stainedred on color check.(It is good)
A planwith consideration of large external overall shrinkage, large sinking at thetip, and shallow internal shrinkage is required.
Metalmold casting conditions may not be suitable.
Atemperature range must be used that is suitable for Permanent mold casting.
T3 Confirmation of mechanical properties
Tensilestrength: 260 N/mm2 Degreeof elongation: 29%
Standards of common brass material and bronze were met sufficiently.
T4 Analysis and confirmation of molten metal components
| Cu | Sn | Pb | Zn | Bi | Others | Cd | ||
|---|---|---|---|---|---|---|---|---|
| 1. | Standard value | 61.2-64.0 | 0.8-2.0 | – | REM | 0.5-2.5 | 0.28-1.55 | |
| 2. | Purchased materials | 63.62 | 1.33 | 0 | 34.48 | 1.54 | 0.66 | 5ppm |
| 3. | Before melting | 63.9 | 1.3 | 0.01 | 32.51 | 1.61 | 0.657 | 5ppm |
| 4. | At the time of test production | 61.6 | 1.26 | 0.01 | 34.47 | 1.42 | 0.669 | 6ppm |
Attentionis required as Zn tends to be depleted and the value of Cu tends to increase.
At thetime of true trial production, Zn is added with consideration of its depletion.
T5 Confirming processability
Theimpression is hard.
Chipsare small.
Processabilityis good.
T6 Evaluation of pressure resistance of trial production
Result
Thistrial product was not perfect, but good results were obtained. Metalmold plan and casting condition have large effects on pressure resistance.
Preliminary trial production
Leakagewas observed in all products in preliminary trial production.Leakagewas observed at the part sandwiched by core sand that solidifies last.Therewas no leakage at the part in direct contact with the metal mold.
True trial production
It canbe improved through thickness settings and the way molten metal flows based onthe metal mold plan.Afterchanging the plan and thickness setting of the product, the results in truetrial production were good.
Results and evaluation
If thecomponents of molten metal are sufficiently managed, metal mold castability byPermanent mold casting is good.
It canbe used for sealed type low-pressure Permanent mold casting.Utilizationin low-pressure Permanent mold casting may be easier than in gravity metal moldcasting method.
However,Permanent mold casting conditions, such as pouring temperature and metal moldtemperature, must be investigated.Massproduction is easily possible in the present state if the Permanent mold castingproduct is small.
Importanceof the Permanent mold casting plan is high, and it is necessary to change the characteristics of the plan from that used for common lead-containing brass.