摘要:The bad collapsibility of the shell of calcined alumina used in precies sion casting is studied by microanalysis method.Two mechanisms have been suggested based on the residual strength of shell and the dimensional changes of shell after pouring.Causes of these two kinds of sintering are studied and the opinions are proposed for the improvement of the shell materials used in precision casting at home.
摘要:The solidification processes of platelike precision castings of 2.5mm-thick ZG l Cr18Ni9 and 2.5/3.5mm-thick ZG 1 Cr17Ni4 Cu 3 Nb are numerically calculated by direct finite difference method (DFDM) in this paper. The distribution of temperature fields, maximum temperature gradient and maximum solidification time gradient in the castings are found out. It is considered that th critical temperature gradient values of platelike stainless steel with investment castings are roughly 6C/cm2 and that the possibility of shrinkage porosity in some sections of the castings can also be guessed with the aid of maximum solidification time gradient.
The Zhengzhou Research Institute of Mechanical EngineeringGu Min
Issue 5, Pages: 13-16(1987)
摘要:The effects of iron contents on mechanical properties of ZZnA127Cu2 alloy was investigated in the range of added iron from 0.05% to 0.2% by orthogonal test method.It is shown the effect of its content is unconside-red. So, in general, the limit of iron impurity is relaxed from 0.13% to 0.2%.
摘要:In this paper we introduce the techniq ue of forming plaster which is made by using foaming agent, research the effect of foaming agent on permeability and strength of foaming plaster,and determine reasonable range of foaming agent. At the same time we base on resource of molding material at home make choice of reasonable recipe of foaming plaster, and research the effect of hydrolyziag ethyl silicate on the strength of foaming plaster.
摘要:This poper have studied the exothermic agent for aluminium bronze. Its effect on the Solidification time of feeder heads and shrinkage deepness is investigated
摘要:The article discusses the results of technology and test of aluminium-silicon alloys, by treating with one step. Results have proved alloys which is smelted by The agent have better mechanical properties. And the poro-sity of sand casting specimens conforms to grade 1 of the standard. Harmful substances in. smelting also conform to the state stipulations. It will get obvious economic benefits to use the technology.
摘要:GJB is a new type of modifier which has strong and multiple effects on the iron melt for the centrifugal casting of cylinder sleeves. It has the virtue of its comprehensive abilities of refining, inoculation and alloying, the effect is obvious. As well as its function and mechanism are investigated in this paper.
摘要:<正> SPECIAL CASTING & NON-FERROUS ALLOYS is a scientific and tech-nical bimonthly facing home and abroad, approved by the National ScienceCommittee of People’s Republic of China. The journal is sponsored jointlyby the Wuhan Institute of Mechanical Technology and the Foundry Instituteof the Chinese Mechanical Engineering Society. And it is the only technicaljournal which reports the newest achievements in the fields of specialcasting and non-ferrous alloys in our country.