Constant current plus pulse current electrical sintering was introduced into the sintering of a ball-milled nanocry stal line Fe-2Cu-2Ni-lMo-0.8C mixed powder. Effect of pulse current charging time on the properties o...
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Constant current plus pulse current electrical sintering was introduced into the sintering of a ball-milled nanocry stal line Fe-2Cu-2Ni-lMo-0.8C mixed powder. Effect of pulse current charging time on the properties of sintered products was studied. Constant electric current sintering was also used for comparison. A nanostructured iron-based material was obtained within 4 minutes of sintering. It has a density of 7.7 g/cm3 (relative density of 98.7 %) with an average grain size (iron-matrix) of 58 nm and carbide particle size of less than 100 nm, a hardness of HRC 64 and transverse rupture strength of 2004 MPa. When only pulsed electric current sintering was used with a sintering time of 5 min, a fine grained iron-base material with density of 7.74 g/cm 3 (relative density of 99.2%), a hardness of HRC 65 and transverse rupture strength of 2045 MPa was obtained.
Powder metallurgy process is a net-shape manufacturing technique that can eliminate or reduce machining *** is economical and environmental friendly since no scrap is being produced and no high energy consuming proces...
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Powder metallurgy process is a net-shape manufacturing technique that can eliminate or reduce machining *** is economical and environmental friendly since no scrap is being produced and no high energy consuming process such as melting is ***,conventional powder metallurgy is not capable of producing complex ***,a recently developed binder-treated warm compaction technique can overcome this problem by increasing the flowability of the mixed *** this study,by using commercially available water-atomized iron powder,cross-shaped part was prepared by warm compaction of a binder-treated iron-base powder at approximately 80°C and then sintered at 1120°***,mechanical property and shape consistency of the prepared part were *** showed that parts with high density and high green strength can be obtained without significant shrinkage or *** present paper demonstrated that the binder-treated warm compaction process can expand the capability of powder metallurgy techniques to produce complex parts.
Many disadvantages exist in the traditional die design method which belongs to serial pattern. It is well known that heat treatment is highly important to the dies. A new idea of concurrent design for heat treatment p...
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Many disadvantages exist in the traditional die design method which belongs to serial pattern. It is well known that heat treatment is highly important to the dies. A new idea of concurrent design for heat treatment process of die and mould was developed in order to overcome the existent shortcomings of heat treatment process. Heat treatment CAD/CAE was integrated with concurrent circumstance and the relevant model was built. These investigations can remarkably improve efficiency, reduce cost and ensure quality of R and D for products.
Effects of rare earth (RE) additions on microstructure and mechanical properties of the wrought AZ31 magnesium alloy were investigated. The results show that, by adding 0.3%, 0.6% and 1.0% RE elements, the as-cast mic...
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Effects of rare earth (RE) additions on microstructure and mechanical properties of the wrought AZ31 magnesium alloy were investigated. The results show that, by adding 0.3%, 0.6% and 1.0% RE elements, the as-cast microstructure can be refined, and the as-cast alloys′ elongation and tensile strength can be improved. After extrusion, the alloy with 0.3% and 0.6% RE additions obtain a finer microstructure and the best mechanical properties, but the alloy with 1.0% RE addition has the coarse Al-RE compound particles in grain boundaries which decreased elongation and tensile properties. Usually, Rare earth (RE) elements were used to improve the creep properties of aluminium-containing magnesium pressure die cast alloys at elevated temperatures. In this paper, it is also found that the high temperature strength of extruded materials can be increased by RE elements additions.
This paper gave a brief discussion on the characteristics of Mg alloys and gave a brief review in the Mg alloys researches, with emphasis on the research progress and fabrication technology. Several vital directions f...
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This paper gave a brief discussion on the characteristics of Mg alloys and gave a brief review in the Mg alloys researches, with emphasis on the research progress and fabrication technology. Several vital directions for the future development were pointed out.
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