摘要:In this paper,the particles of Al-Si alloy with 12.54 percent of silicon were producedby nitrogen atomization.These particles were heated to 700℃ and re-melted.The molten of Al-Sialloy with 13.23 percent of silicon and modified with Sr has been treated with direct current. Theeffect of different processing condition on the morphologies of eutectoid silicon in Al-St alloy wasinvestigated with TEM and SEM.Results show that in samples which were produced using atomized particles or re-melting treatment,the morphologies of eutectoid silicon were spheroidal or ribbon like,while those modified with Sr,the eutectoid silicon presented some curved fibrous shape.After direct current treatment,the morphologies of eutectoid silicon could be changed intospheroidal.Their particle size was within 50-200 urn.
关键词:Al-Si Alloys;Speed Solidification;Direct Current Treatment;Morphologies of Eutectoid Silicon
摘要:As the kind of plaster and the technology of process were fixed,the influence of water(temperature of water,underground water,distill water.magnetizing water)on properties ofplaster mold has been studied.Experimental results show that when temperature of water is raisedthe flowability of plaster slurry is decreased the gelation time is shortened and the strength an4shrinkage increased with distilled water and magnetizing water,the strength and shrinkage are increased obviously.
摘要:The MgO-based ceramic core has been investigeted.The production practice of hollow castings of stainless steels,casting steels and nickel--base alloys has shown that application ofthis MgO-base core is satisfied under air,vacuum and directional solidification condition.
摘要:A new type coating used for Al-Li alloy melting and casting has been studied. Itshowed that the coating exhibited good chemical stability.There was no reaction between the coating and Al-Li alloy melt and the iron crucible and the tools were not corroded by the coating so thatthe composition and impurity of alloys could be controled effectively.In addition,the coating layerwas uniform,tight and easy to be cleaned.
摘要:It is known that thermal analysis method can record the time-temperature curves of aspecimen during solidification. In this paper,according to the thermal analysis curves and manyexperiments data,a compound rule of Na-Mg modification for Al-St Alloy has been obtained, simultaneously mathematical calculating formulas between △T and σb is put forward. Finally calculated numbers had been compared with the experimental results.the facts have proved that thismethod is very useful to production.