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本文研究了由基体元素W、Ni、Fe、Al和Ti的混合粉末经等静压成型和液相烧结所制的W基高比重合金。Al和Ti的添加导致γ′硬化相在Ni基基体上的沉淀析出,因此,提高了粘结相的强度和该高比重合金的机械性能。用固结的高比重合金制成离子箔进行了透射电镜研究,结果发现一个引人注意的显微组织: γ′相以细长方体显微弥散的形式与γ基体粘结; W-基体界面十分平滑,绝没有堆积或脱节区; 同时,看到硬度值比常规的W-Ni-Fe高比重合金有所增加((?)10%) 精心制做了AFNOR标准拉伸大型试样,并做了显微组织与机械性能相互关联的试验。结果表明,尽管密度不够高(ρ=99%理论ρ),但硬度、极限强度和屈服强度都有显著提高,而延性却没有多少降低。所观察到的孔隙是由于Al和Ti的氧化物(Al_2O_3型)所造成的。烧结后进行的热机械处理——在γ′溶线和γ固相线温度之间——保证了完全的致密化,并提高了机械性能,得到了各项性能的最佳值:拉伸强度达1070牛顿/毫米~2,压缩强度达3850牛顿/毫米~2,而相应的延性为8.5%和56%;屈服强度达920牛顿/毫米~2,硬度达400HV(30kg)。
In this paper, a W-based high specific gravity alloy prepared by isostatic pressing and liquid phase sintering of a mixed powder of matrix elements W, Ni, Fe, Al and Ti was studied. The addition of Al and Ti results in the precipitation of the γ’-hardening phase on the Ni-based substrate, thereby increasing the strength of the binder phase and the mechanical properties of the high specific gravity alloy. Transmission electron microscopy was performed on the ion-foil made of a consolidated high specific gravity alloy. As a result, an attractive microstructure was found: the γ ’phase adhered to the γ matrix in the form of fine dispersion of the slender body; and the interface of the W- At the same time, it is seen that the hardness value has been increased (10%) compared with the conventional W-Ni-Fe high specific gravity alloy (AFNOR standard tensile large sample), and made The microstructure and mechanical properties of interrelated experiments. The results show that although the density is not high enough (ρ = 99% theoretical ρ), the hardness, ultimate strength and yield strength are significantly increased, while the ductility does not decrease much. The observed porosity is due to the oxides of Al and Ti (Al 2 O 3 type). The thermomechanical treatment after sintering - between the gamma prime and gamma solidus temperatures - ensures complete densification and improved mechanical properties, resulting in the best of properties: tensile strength Up to 1070 N / mm2, a compressive strength of 3850 N / mm2, with corresponding ductility of 8.5% and 56%, a yield strength of 920 N / mm2 and a hardness of 400 HV (30 kg).