Daoren GONG
,
Zhongmin YANG
,
Qiang SHEN
,
Lianmeng ZHANG
材料科学技术（英文）
Mo is difficult to sinter densely at a relatively low temperature due to its high melting point. In the present paper, by adding different weight contents of Ni and Cu additives, Mo alloys have been densified at 1473 K for an hour by hot-pressing method, and the optimum contents of Cu and Ni additives have been acquired: when the contents of Ni and Cu are 3 and 2 wt pct respectively, the relative density of the sample reaches the maximum value. It was found that when the Ni-Cu solid solution was added into Mo alloys, the achieved density is higher than the case of Ni and Cu additives. The experimental results indicate that, Ni and Cu play different roles in the process of sintering, the Ni-Cu solid solution has the same function as Ni and Cu additives in the course of sintering Mo alloys, It shows more activating sintering feature for Mo than the Ni and Cu additives.
关键词:
Mo alloys
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null
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Zhongmin YANG
,
Lianmeng ZHANG
,
Qiang SHEN
材料科学技术（英文）
A sedimentation method is proposed to fabricate functionally graded materials (FGMs) with the continuous and smooth variations of composition. The relations between the compositional distribution of deposited body and the powder characteristics of raw materials as well as settling parameters are derived. Subsequently, the mathematical model of forming FGM based on the co-sedimentation has been established. At last, numerical simulations are conducted to explore the effects of the particle sizes of raw materials and suspension height on the compositional distribution of final products.
关键词:
Calculation
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Chuanbin WANG
,
Qiang SHEN
,
Lianmeng ZHANG
材料科学技术（英文）
In this study, Cu was added as the third additive to lower the sintering temperature of W-Ni-Fe alloy. By adding 2 wt pct Cu, a dense 93W-3.5Ni-1.5Fe-2.0Cu tungsten alloy was obtained by hot-pressing at a low temperature of 1573 K which is a process of liquid-phase sintering. As a result, the morphology of W-Ni-Fe alloy changed obviously after the addition of Cu and the alloy had higher relative density and rupture strength. The mechanism of the densification of W-Ni-Fe-Cu alloy at the low temperature was then mainly investigated. It was found that, part sintering activators Ni and Fe could exist in liquid form at 1573 K due to the addition of Cu, which made it easy for Ni and Fe to dissolve W and thus the full densification of W-Ni-Fe-Cu alloy at the low temperature was realized.
关键词:
W-Ni-Fe alloy
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null
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