In order to further improve the precision forming efficiency of a sand mold digital patternless casting and reduce the amount of sand mold cutting, a method for near-net forming of the sand mold with digital flexible ...In order to further improve the precision forming efficiency of a sand mold digital patternless casting and reduce the amount of sand mold cutting, a method for near-net forming of the sand mold with digital flexible extrusion technology was put forward. The theory, optimization algorithm and technology for sand mold nearnet forming were studied. Experimental results show that the sand mold forming efficiency can be increased by 34%, and the molding sand can be reduced by 44%. The method for near-net forming of a sand mold with digital flexible extrusion technology can effectively promote the application of digital patternless casting technology in the mass production of castings and thus greatly improves the efficiency and automation of sand mold manufacturing.展开更多
A novel technology of continuous semisolid extrusion Process(CSEP) was adopted to produce AZ31 alloy structural materials.Effects of technological conditions on the microstructures of AZ31 alloy during CSEP were studi...A novel technology of continuous semisolid extrusion Process(CSEP) was adopted to produce AZ31 alloy structural materials.Effects of technological conditions on the microstructures of AZ31 alloy during CSEP were studied.During the casting process,the non-uniform distribution of microstructures was found in the roll-shoe gap.Microstructure evolution from dendrite to rosette or spherical grains was observed during the casting process by CSEP.The results show that high casting temperature and large cooling intensity can cause non-equilibrium solidification region near the roll surface,large roll-shoe gap width and high cooling intensity can lead to the formation of discontinuous solidification microstructure and slip plane near the shoe surface,which will finally cause the failure of the casting process.The proper casting temperature range of 730-750 °C,the roll cooling intensity of 0.4 L/s and the roll-shoe gap width of less than 10 mm are suggested.Under the suggested conditions,the product with diameter of 10 mm of AZ31 alloy with smooth surface and homogeneous striped microstructure is obtained.The average strength of the product after heat treatment reaches 270 MPa,and the elongation is 16%.展开更多
Low aqueous solubility of API is a problem of drug product development.There are several methods to enhance drug solubility.Although drugs can increase solubility using many chemical and physical modifications,the few...Low aqueous solubility of API is a problem of drug product development.There are several methods to enhance drug solubility.Although drugs can increase solubility using many chemical and physical modifications,the few methods are able to enhance drug solubility for industrial scale[1].Hot-melt extrusion is one reliable process for enhancing drug solubility in a large scale production.It has been recognized as a one step process with several advantages.It can not only increase solubility of drug,but can also be used as a process to prepare controlled release dosage forms.Using a biodegradable polymer with hot-melt extrusion,the drug release of up to 1–6 months can be achieved[2].展开更多
With the development and widely used of the compute r technology, the CAD has been more and more used in the process of designing prod uct. The number of the engineering drawings will greatly increase because of the c...With the development and widely used of the compute r technology, the CAD has been more and more used in the process of designing prod uct. The number of the engineering drawings will greatly increase because of the continually appearance of the new products. As a result, it has become a badly needed to be solved problem for us that how to rapidly and efficiently search an d appropriately preserve and manage the drawings. In this paper, a method of bui lding the product drawing management system for extrusion aluminum-type materia ls is discussed. This system is designed for the profile graphic of the aluminou s section material management by using Group Technology (GT) principle. Accordin g to the GT, we developed a classifying-coding system and drawing management sy stem about the extrusion aluminum-type materials through analyzing a large numb er of extrusion aluminum-type materials section drawings. The coding system has realized the flexible coding and hidden coding of the extrusion aluminum-type materials and then enhanced the flexibility and the expansible of the system. By supplying the designer with the human-computer interaction interface the drawi ng management system has been able to resolve many difficult problems such as se arch and manage the existed drawings about the extrusion aluminum-type material s very well. At the same time, it also helps the developing work enhance the abi lity of inheriting by applying this kind of variant method. In a word, with the help of this system we can not only shorten the designing time greatly and reduc e the cost of the product but also research the designing drawings rapidly. In o rder to output the data information related to the part drawing, the system uses the data-exchange standard to which the drawing support-software adapted as d ata-exchange interface. The system is advantageous to building a standard of dr awing design and increasing the efficiency of searching drawing and enhancing th e information management, which have had a base for building the best management system in the future. In addition, the paper has a detailed analysis about the principle of flexible classification code and data structure.展开更多
Based on the general solution to stress equilibrium differential equation and the analytical expressions in mechanical field of superplastic extrusion through cone-shaped die, in this paper the theoretical formulae ha...Based on the general solution to stress equilibrium differential equation and the analytical expressions in mechanical field of superplastic extrusion through cone-shaped die, in this paper the theoretical formulae have been established for the technological processing specifications of non-steady and steady extrusions through cone-shaped die. Experimental results on the typical superplastic alloy Zn-5wt/Al are in good agreement with the theoretical calculations.展开更多
The technological parameters have important effects on molding process of lead-clad glass fiber composite wire. If the extrusion force, temperature and gap size are too large or small, a dead zone will form in the fro...The technological parameters have important effects on molding process of lead-clad glass fiber composite wire. If the extrusion force, temperature and gap size are too large or small, a dead zone will form in the front of the inlet mold orifice, and the continuous clad extrusion and coating speed will be influenced. Under the condition of equal flow, the maximum and minimum theoretical values of the extrusion force, temperature and gap size are studied. The results show that the gap size is a key parameter that affects the continuous clad extrusion and coating speed when the extrusion force and temperature are kept constant. The maximum value (H_ max) of gap size is 0.50mm and the minimum one (H_ min) is 0.12mm. At a gap size of 0.17mm or 0.29mm, the maximum of metal extrusion per unit time and optimal coating speed can be obtained when the extrusion temperature is 300℃ and the extrusion force is 450kN.展开更多
基金financially supported by the National Science Foundation for Distinguished Young Scholars of China(Grant No.51525503)
文摘In order to further improve the precision forming efficiency of a sand mold digital patternless casting and reduce the amount of sand mold cutting, a method for near-net forming of the sand mold with digital flexible extrusion technology was put forward. The theory, optimization algorithm and technology for sand mold nearnet forming were studied. Experimental results show that the sand mold forming efficiency can be increased by 34%, and the molding sand can be reduced by 44%. The method for near-net forming of a sand mold with digital flexible extrusion technology can effectively promote the application of digital patternless casting technology in the mass production of castings and thus greatly improves the efficiency and automation of sand mold manufacturing.
基金Projects(50974038,51034002) supported by the National Natural Science Foundation of ChinaProject (2007AA03Z111) supported by Natural High-tech Research and Development Program of ChinaProjects(N090502003) supported by the Basic Scientific Research Operation of Center University,China
文摘A novel technology of continuous semisolid extrusion Process(CSEP) was adopted to produce AZ31 alloy structural materials.Effects of technological conditions on the microstructures of AZ31 alloy during CSEP were studied.During the casting process,the non-uniform distribution of microstructures was found in the roll-shoe gap.Microstructure evolution from dendrite to rosette or spherical grains was observed during the casting process by CSEP.The results show that high casting temperature and large cooling intensity can cause non-equilibrium solidification region near the roll surface,large roll-shoe gap width and high cooling intensity can lead to the formation of discontinuous solidification microstructure and slip plane near the shoe surface,which will finally cause the failure of the casting process.The proper casting temperature range of 730-750 °C,the roll cooling intensity of 0.4 L/s and the roll-shoe gap width of less than 10 mm are suggested.Under the suggested conditions,the product with diameter of 10 mm of AZ31 alloy with smooth surface and homogeneous striped microstructure is obtained.The average strength of the product after heat treatment reaches 270 MPa,and the elongation is 16%.
文摘Low aqueous solubility of API is a problem of drug product development.There are several methods to enhance drug solubility.Although drugs can increase solubility using many chemical and physical modifications,the few methods are able to enhance drug solubility for industrial scale[1].Hot-melt extrusion is one reliable process for enhancing drug solubility in a large scale production.It has been recognized as a one step process with several advantages.It can not only increase solubility of drug,but can also be used as a process to prepare controlled release dosage forms.Using a biodegradable polymer with hot-melt extrusion,the drug release of up to 1–6 months can be achieved[2].
文摘With the development and widely used of the compute r technology, the CAD has been more and more used in the process of designing prod uct. The number of the engineering drawings will greatly increase because of the continually appearance of the new products. As a result, it has become a badly needed to be solved problem for us that how to rapidly and efficiently search an d appropriately preserve and manage the drawings. In this paper, a method of bui lding the product drawing management system for extrusion aluminum-type materia ls is discussed. This system is designed for the profile graphic of the aluminou s section material management by using Group Technology (GT) principle. Accordin g to the GT, we developed a classifying-coding system and drawing management sy stem about the extrusion aluminum-type materials through analyzing a large numb er of extrusion aluminum-type materials section drawings. The coding system has realized the flexible coding and hidden coding of the extrusion aluminum-type materials and then enhanced the flexibility and the expansible of the system. By supplying the designer with the human-computer interaction interface the drawi ng management system has been able to resolve many difficult problems such as se arch and manage the existed drawings about the extrusion aluminum-type material s very well. At the same time, it also helps the developing work enhance the abi lity of inheriting by applying this kind of variant method. In a word, with the help of this system we can not only shorten the designing time greatly and reduc e the cost of the product but also research the designing drawings rapidly. In o rder to output the data information related to the part drawing, the system uses the data-exchange standard to which the drawing support-software adapted as d ata-exchange interface. The system is advantageous to building a standard of dr awing design and increasing the efficiency of searching drawing and enhancing th e information management, which have had a base for building the best management system in the future. In addition, the paper has a detailed analysis about the principle of flexible classification code and data structure.
文摘Based on the general solution to stress equilibrium differential equation and the analytical expressions in mechanical field of superplastic extrusion through cone-shaped die, in this paper the theoretical formulae have been established for the technological processing specifications of non-steady and steady extrusions through cone-shaped die. Experimental results on the typical superplastic alloy Zn-5wt/Al are in good agreement with the theoretical calculations.
文摘The technological parameters have important effects on molding process of lead-clad glass fiber composite wire. If the extrusion force, temperature and gap size are too large or small, a dead zone will form in the front of the inlet mold orifice, and the continuous clad extrusion and coating speed will be influenced. Under the condition of equal flow, the maximum and minimum theoretical values of the extrusion force, temperature and gap size are studied. The results show that the gap size is a key parameter that affects the continuous clad extrusion and coating speed when the extrusion force and temperature are kept constant. The maximum value (H_ max) of gap size is 0.50mm and the minimum one (H_ min) is 0.12mm. At a gap size of 0.17mm or 0.29mm, the maximum of metal extrusion per unit time and optimal coating speed can be obtained when the extrusion temperature is 300℃ and the extrusion force is 450kN.
