摘要:In this paper,the effect of various factors of technology on the ductile iron investment casting in sodium silicate ceramic shell have been discussed. Such as raw materials choice, shell making technology, temperature field in shell mould, etc. Study has proved that ceramic shell making by Al-Si system refractory materials with main crystal of Mollite or Kaolinite will be the ideal choice for investment casting ductile iron.
摘要:The performance of the cast Aluminium Graphite composites have been investigated. The composites are prepared by directly adding graphite particles to the molten base alloy-Al-4.5Cu-Si-Mg. The effects of the size, distribution and content of graphite particle upon mechanical properties and wear resistance are studied. The composites is also made of squeeze and gravity casting, it is found that the properties of sgueeze casting is superior to those of gravity casting. The cast aluminium graphite composites have excellent wear resistance and can be used as a good piston and bearing materials.
摘要:In this paper, based on the viewpoint of unification ofcrystallization of Al-Si alloys, change of growth morphology and crystal-lographic structure of Si after Na modification, and modification mechanism, and guided by basic theory, investigation works on the crystallization and modification of Al-Si alloys were reviewed comprehensively. Then a comparatively reasonable Na modification mechanism was proposed.
摘要:This paper preliminary approach the possibility of primary melting technique for high silicon Al-Si alloy used in piston of motor engine under industrial production condition. The experimental results have shown that the alloy of qualified chemical composition can be obtained in this way introduced furthermore, after suitable modification, satisfying metallographic structure and mechanical properties can be received.
摘要:The underside shrinkage in ZA-27 alloy sand mold castings has been studied. The experimental results show that the content of aluminum in the top of the casting is much more than in the bottom and it is such a macrosegregation of aluminum during solidification that leads to the formation of the underside shrinkage. The mathods for control and prevention of this kind of defect are also given in this paper.