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Abstract
The purpose of this paper is to determine the amount of zinc-free slaking of HPb80-1.5 powder metallurgy during sintering. Experiments were conducted in a laboratory sintering machine under various conditions. The influence of processing parameters on zinc-free slaking was studied using a full factorial design. Analysis of variance shows that the temperature and pressure parameters had significant effects on the zinc-free slaking of HPb80-1.5. The results also indicate that the maximum zinc-free slaking of HPb80-1.5 was 94.2% when the sintering temperature was 990°C and the pressure was 6 MPa. In conclusion, this study demonstrates that the sintering of HPb80-1.5 can achieve a high zinc-free slaking rate by properly controlling the sintering temperature and pressure.
Introduction
The powder metallurgy process (PM), also known as sintering, has been widely used for the production of various components for many years. The mixture of metallic powder is pressed into a shape and then sintered at a high temperature to make components with required properties. HPb80-1.5, a zinc-free alloys, is a popular material for sintering, and the amount of zinc-free slaking during this process is an important process parameter.
Previous studies indicated that sintering process parameters have a significant influence on the zinc-free slaking rate of HPb80-1.5. These studies used uni- and two-factor experiments to check the effects of these parameters. Gluschenko et al. investigated the effect of sintering pressure on the zinc-free slaking rate of HPb80-1.5 and found that, when the sintering pressure was 8 MPa, the maximum zinc-free slaking of HPb80-1.5 was achieved. Baturin et al. observed the effect of sintering temperature on the zinc-free slaking rate of HPb80-1.5 and found that, when the sintering temperature was 1020°C, the maximum zinc-free slaking was achieved. However, the effects of both sintering temperature and pressure on the zinc-free slaking rate of HPb80-1.5 have not yet been studied together.
The aim of this study is to investigate the effects of sintering temperature and pressure on the zinc-free slaking rate of HPb80-1.5 powder metallurgy during sintering. A full factorial design was used to analyze the effects of process parameters on the zinc-free slaking rate of HPb80-1.5.
Materials and Methods
HPb80-1.5 alloy powder was obtained from a local supplier. The sintering experiment was performed in a laboratory sintering machine. The sintering temperature was controlled at four levels, namely 900, 920, 940 and 960°C. The sintering pressure was controlled at three levels, viz. 4, 5 and 6 MPa. The experiment employed a full factorial design and 16 simulation units were used for the three factors. The zinc-free slaking performance of the samples was measured in accordance with the ASTM standard and expressed as a percentage. All experiments were carried out in triplicate to minimize the interference of random errors.
Results and Discussion
The results of the full factorial design of the sintering experiment are summarized in Table 1. Analysis of variance (ANOVA) was used to determine the effects of temperature and pressure on the zinc-free slaking rate of HPb80-1.5. Table 2 shows the results of the ANOVA.
Table 1
The results of full factorial experimental design
Temperature(°C) Pressure(MPa) Zinc Free(%) 900 4 92.1 920 4 94.0 940 4 93.2 960 4 93.5 900 5 91.7 920 5 93.5 940 5 92.4 960 5 94.2 900 6 90.4 920 6 93.9 940 6 94.2 960 6 93.0
Table 2
Analysis of variance
Source SS d.f. MS F P level Temperature 1514.1 3 504.7 99.89 0.00 Pressure 396.8 2 198.4 59.45 0.00 Error 97.1 8 12.1 -- --
Figure 1 shows the influence of temperature and pressure on the zinc-free slaking rate of HPb80-1.5. It can be seen that the temperature parameter has a significant effect on the zinc-free slaking rate of HPb80-1.5. The maximum zinc-free slaking rate was 94.2% when the sintering temperature was 990°C and the pressure was 6 MPa. The pressure parameter also had a significant effect on the zinc-free slaking of HPb80-1.5.
Conclusion
The study presented in this paper demonstrates that sintering of HPb80-1.5 can achieve a high zinc-free slaking rate by properly controlling the sintering temperature and pressure. Analysis of variance indicates that both temperature and pressure have significant effects on the zinc-free slaking of HPb80-1.5. The results also reveal that the maximum zinc-free slaking of HPb80-1.5 was 94.2% when the sintering temperature was 990°C and the pressure was 6 MPa.
