Most view articles
2017, 47(1):1-4.
DOI: 10.12044/j.issn.1007-2330.2017.01.001
Abstract:
The main lightweight structure materials including lightweight alloy and composite materials for aerospace applications were introduced in the article. The development direction of the lightweight structure materials are analysed briefly combining the application requirements of aerospace.
The main lightweight structure materials including lightweight alloy and composite materials for aerospace applications were introduced in the article. The development direction of the lightweight structure materials are analysed briefly combining the application requirements of aerospace.
2017, 47(3):57-60.
DOI: 10.12044/j.issn.1007-2330.2017.03.013
Abstract:
The cure kinetics of the epoxy resin 607 for an out-of-autoclave(OoA) composite was investigated by differential scanning calorimetry(DSC),and the cure kinetic formula of the resin was established. The prepreg with dry fiber regions remaining and the OoA composites were prepared. The quality and properties of the T800/607 composite were studied. The results indicated that the T800/607 prepreg owed a tack life at room temperature over 30 days and the void content of the OoA composite is far below 1%. The short beam shear strength and flexural strength of the OoA composite are 96.7 and 1480 MPa,respectively, which can be compared with the autoclave cured ones.
The cure kinetics of the epoxy resin 607 for an out-of-autoclave(OoA) composite was investigated by differential scanning calorimetry(DSC),and the cure kinetic formula of the resin was established. The prepreg with dry fiber regions remaining and the OoA composites were prepared. The quality and properties of the T800/607 composite were studied. The results indicated that the T800/607 prepreg owed a tack life at room temperature over 30 days and the void content of the OoA composite is far below 1%. The short beam shear strength and flexural strength of the OoA composite are 96.7 and 1480 MPa,respectively, which can be compared with the autoclave cured ones.
2016, 46(6):68-73, 78.
Abstract:
The pyrolytic process and volatiles of PICA porous phenolics at different stages were investigated by TG-FTIR and PyGC-MS.The results demonstrated that PICA porous phenolics presented two evident weight loss processes.The desorption of small molecules of PICA porous phenolics took place during the first process and H2O,CO2,HOCH2CH2OH are the main volatiles.The molecular chain of porous phenolics broke up and phenols,benzene series,fused ring aromatics evolved during the second process and it is the main stage of thermal degradation. After high-temperature pyrolysis loose and porous char with a certain strength is formed by the combination of porous phenolics matrix with high porosity carbon fiber reinforcement.
The pyrolytic process and volatiles of PICA porous phenolics at different stages were investigated by TG-FTIR and PyGC-MS.The results demonstrated that PICA porous phenolics presented two evident weight loss processes.The desorption of small molecules of PICA porous phenolics took place during the first process and H2O,CO2,HOCH2CH2OH are the main volatiles.The molecular chain of porous phenolics broke up and phenols,benzene series,fused ring aromatics evolved during the second process and it is the main stage of thermal degradation. After high-temperature pyrolysis loose and porous char with a certain strength is formed by the combination of porous phenolics matrix with high porosity carbon fiber reinforcement.
2000(4).
Abstract:
阐述了铝合金在低温下的力学性能随温度的变化规律：在低温下拉伸性能提高、韧性改善、疲劳强度增加，且介质不同铝合金表现出不同的力学性能。并分析了这些力学性能变化规律的机理，同时对在极低温下某些铝合金锯齿变形的现象、特征、形成机理以及对力学性能的影响作了分析说明。
阐述了铝合金在低温下的力学性能随温度的变化规律：在低温下拉伸性能提高、韧性改善、疲劳强度增加，且介质不同铝合金表现出不同的力学性能。并分析了这些力学性能变化规律的机理，同时对在极低温下某些铝合金锯齿变形的现象、特征、形成机理以及对力学性能的影响作了分析说明。
2016, 46(6):1-5.
Abstract:
The aerodynamic heating environment for spacecrafts currently under development typically possesses the following characteristics:high enthalpy, high heat flux and long heating time. This in turn has lead to the shift of active research work of heat shield materials, e.g., phenolic-resin based composites, towards enhancing properties such as higher ablation resistance, good heat insulation and even lower densities. To overcome the limitation of materials’ intrinsic properties and to improve their performances, both ablative(resin based) and non-ablative(ceramic based) types of heat shield materials can be further optimized by applying functional coating materials on top of the ablation surface. This review has focused on the recent research effort on the coating material for different thermal protection systems and categorized them into two major types:ablative and non-ablative. Having obtained a comprehensive understanding about their pros and cons, a possible solution is proposed at the end of this article for resin-based ablative composites:coatings consist of silicon-based preceramic polymers that can be cured around the same temperature as phenolic resin but ceramized in-situ during flight.
The aerodynamic heating environment for spacecrafts currently under development typically possesses the following characteristics:high enthalpy, high heat flux and long heating time. This in turn has lead to the shift of active research work of heat shield materials, e.g., phenolic-resin based composites, towards enhancing properties such as higher ablation resistance, good heat insulation and even lower densities. To overcome the limitation of materials’ intrinsic properties and to improve their performances, both ablative(resin based) and non-ablative(ceramic based) types of heat shield materials can be further optimized by applying functional coating materials on top of the ablation surface. This review has focused on the recent research effort on the coating material for different thermal protection systems and categorized them into two major types:ablative and non-ablative. Having obtained a comprehensive understanding about their pros and cons, a possible solution is proposed at the end of this article for resin-based ablative composites:coatings consist of silicon-based preceramic polymers that can be cured around the same temperature as phenolic resin but ceramized in-situ during flight.
2017, 47(1):37-41.
DOI: 10.12044/j.issn.1007-2330.2017.01.007
Abstract:
The external and internal hydro-proof test investigation of the cylinder structures are developed in the present paper. The needling C/C composite cylinder sample preparation and the fixture are designed according to the testing condition. The stress distribution information of the structures is obtained during the test process. The 3D hydro-proof FEM simulation model is established to compare with the experiment results. The simulation results are in good agreement with the test results,which indicates the validity and accuracy of the FEM simulation model. The test and simulation conclusions can provide some important guidance for the nozzle carbon/carbon composite with cone structure design, material constitutive model parameter modification and structure safety tolerance prediction.
The external and internal hydro-proof test investigation of the cylinder structures are developed in the present paper. The needling C/C composite cylinder sample preparation and the fixture are designed according to the testing condition. The stress distribution information of the structures is obtained during the test process. The 3D hydro-proof FEM simulation model is established to compare with the experiment results. The simulation results are in good agreement with the test results,which indicates the validity and accuracy of the FEM simulation model. The test and simulation conclusions can provide some important guidance for the nozzle carbon/carbon composite with cone structure design, material constitutive model parameter modification and structure safety tolerance prediction.
2017, 47(1):72-76.
DOI: 10.12044/j.issn.1007-2330.2017.01.015
Abstract:
Based on the electron bean circular weld on 2219 T852 transition ring and T87 shell section used for tank, the normal and low mechanical properties of the electron beam welded joints in the segment level were tested, and the staggered amount,fracture types and microstructure of the welded joints were analyzed. The following conclusions can be drawn.The normal and low strength effect coefficient of the segment level electron beam welded joints on 2219 T852 transition ring and T87 shell section are 0.63, and relative to the normal temperature, the low temperature mechanical properties of welded joints have been improved. The staggered amount is inversely proportional to the mechanical properties of welded joints,and it has the most significant effect to elongation, and low temperature should help to ease the weakening effect of staggered to the mechanical properties of welded joints. Because of the uneven tissue and the discontinuous structure of the electron beam welded joints,especially T852 side heat affected zone with coarse grains,the T852 side heat affected zone and the roots of welded joints are the weak area of the electron beam weld, and welded joint is easy to fracture in the area.
Based on the electron bean circular weld on 2219 T852 transition ring and T87 shell section used for tank, the normal and low mechanical properties of the electron beam welded joints in the segment level were tested, and the staggered amount,fracture types and microstructure of the welded joints were analyzed. The following conclusions can be drawn.The normal and low strength effect coefficient of the segment level electron beam welded joints on 2219 T852 transition ring and T87 shell section are 0.63, and relative to the normal temperature, the low temperature mechanical properties of welded joints have been improved. The staggered amount is inversely proportional to the mechanical properties of welded joints,and it has the most significant effect to elongation, and low temperature should help to ease the weakening effect of staggered to the mechanical properties of welded joints. Because of the uneven tissue and the discontinuous structure of the electron beam welded joints,especially T852 side heat affected zone with coarse grains,the T852 side heat affected zone and the roots of welded joints are the weak area of the electron beam weld, and welded joint is easy to fracture in the area.
2016, 46(6):26-29, 63.
Abstract:
The mirrors play a key role in the space optical system, and it has been developed to the fourth generation of C/SiC composites. C/SiCcomposites have become very important materials for light-weight mirrors because of the advantage of low density, high stiffness and strength, considerable flexibility in structural design and so on.In this paper, the characteristics of four generation of mirror were contrast, the preparation process and the structure design of C/SiC composites were summarized, the development of the C/SiC mirror at home and abroad is reviewed.
The mirrors play a key role in the space optical system, and it has been developed to the fourth generation of C/SiC composites. C/SiCcomposites have become very important materials for light-weight mirrors because of the advantage of low density, high stiffness and strength, considerable flexibility in structural design and so on.In this paper, the characteristics of four generation of mirror were contrast, the preparation process and the structure design of C/SiC composites were summarized, the development of the C/SiC mirror at home and abroad is reviewed.
2017, 47(1):13-19.
DOI: 10.12044/j.issn.1007-2330.2017.01.003
Abstract:
The status of applications such as HIP technology in the fields of metals, metal matrix composites, inorganic non-metallic materials and polymer materials is discussed, and the simulation technology of the isostatic pressing is reviewed. At the same time, the development trend of composite molding process of the isostatic pressing technology and 3D printing technology is analyzed, and the future of isostatic pressing techniques is prospected.
The status of applications such as HIP technology in the fields of metals, metal matrix composites, inorganic non-metallic materials and polymer materials is discussed, and the simulation technology of the isostatic pressing is reviewed. At the same time, the development trend of composite molding process of the isostatic pressing technology and 3D printing technology is analyzed, and the future of isostatic pressing techniques is prospected.
2016, 46(6):6-10.
Abstract:
Due to its amazing properties, Ti alloys are widely used in aerospace and aerial industry. HIP powder metallurgy process, which is suspected to a proposal approach to solve Ti alloys’ fabrication problem, is investigated throughout the world. In this paper, it’s character, orgination and development is introduced. Meanwhile, the investigation, approvemnet and practical application of the process of Aerospace Research Institute of Materials & Processing Technology is also introduced.
Due to its amazing properties, Ti alloys are widely used in aerospace and aerial industry. HIP powder metallurgy process, which is suspected to a proposal approach to solve Ti alloys’ fabrication problem, is investigated throughout the world. In this paper, it’s character, orgination and development is introduced. Meanwhile, the investigation, approvemnet and practical application of the process of Aerospace Research Institute of Materials & Processing Technology is also introduced.
2017, 47(1):25-28,36.
DOI: 10.12044/j.issn.1007-2330.2017.01.005
Abstract:
Based on the theory of experimental modal analysis, the modal theory and testing system of composite laminates is established. Firstly, composite laminates of 150 mm×80 mm×3.75 mm (length×width×thickness) were built-up. By using DH5922N dynamic data acquisition instrument, the frequency response function and the excitation signal sensed by acceleration sensor and force hammer are obtained. And frequency response function is analysised in the dynamic signal analysis system DHDAS. The first and second natural frequencies were 323.103 Hz and 656.180 Hz respectively, and the shift values of each measurement point corresponding to the frequency were obtained. The experimental results show that the experimental theory and the equipment used in this paper can be used to accurately extract the modal information of composite laminates.
Based on the theory of experimental modal analysis, the modal theory and testing system of composite laminates is established. Firstly, composite laminates of 150 mm×80 mm×3.75 mm (length×width×thickness) were built-up. By using DH5922N dynamic data acquisition instrument, the frequency response function and the excitation signal sensed by acceleration sensor and force hammer are obtained. And frequency response function is analysised in the dynamic signal analysis system DHDAS. The first and second natural frequencies were 323.103 Hz and 656.180 Hz respectively, and the shift values of each measurement point corresponding to the frequency were obtained. The experimental results show that the experimental theory and the equipment used in this paper can be used to accurately extract the modal information of composite laminates.
2017, 47(1):77-80.
DOI: 10.12044/j.issn.1007-2330.2017.01.016
Abstract:
The quality of spot welded joints was evaluated by the scanning acoustic microscope (SAM). The change characteristics of gray level of C-scan image were analyzed. The feasibility of evaluating the quality of spot welded joints and measuring the nugget diameter by using the change of the gray level was provided. And we analyzed the spot welded joints of 1.0 mm stainless steel under different welding parameters. The calculated values of nugget diameter are compared with the measured values by macrophotograph of samples. The results show that this method is available for measuring nugget diameter of the spot welded joints, and can avoid the influence of artificial factors and reduce production costs. The accuracy of testing result was verified by contrasting the metallographs of actual spot welded joints cross section.
The quality of spot welded joints was evaluated by the scanning acoustic microscope (SAM). The change characteristics of gray level of C-scan image were analyzed. The feasibility of evaluating the quality of spot welded joints and measuring the nugget diameter by using the change of the gray level was provided. And we analyzed the spot welded joints of 1.0 mm stainless steel under different welding parameters. The calculated values of nugget diameter are compared with the measured values by macrophotograph of samples. The results show that this method is available for measuring nugget diameter of the spot welded joints, and can avoid the influence of artificial factors and reduce production costs. The accuracy of testing result was verified by contrasting the metallographs of actual spot welded joints cross section.
2017, 47(1):67-71.
DOI: 10.12044/j.issn.1007-2330.2017.01.014
Abstract:
The blade in the installation of test failed in the operating process,fault location is located in the root of blade.Through observation,testing and analysis of fault component,the reason blade produced by low cycle fatigue fracture is identified due to improper control of production process.The blade root curing is incomplete in local area,which causes the strength and stiffness of very low. Fiber beam between curing not completely of resin cannot will load effective of passed to near of fiber beam, so dang by fatigue load role in structure stress concentrated regional first occurred layered cracking, and extended until eventually lost stability fracture.The direction for improvement is pointed out.
The blade in the installation of test failed in the operating process,fault location is located in the root of blade.Through observation,testing and analysis of fault component,the reason blade produced by low cycle fatigue fracture is identified due to improper control of production process.The blade root curing is incomplete in local area,which causes the strength and stiffness of very low. Fiber beam between curing not completely of resin cannot will load effective of passed to near of fiber beam, so dang by fatigue load role in structure stress concentrated regional first occurred layered cracking, and extended until eventually lost stability fracture.The direction for improvement is pointed out.
2017, 47(3):6-9.
DOI: 10.12044/j.issn.1007-2330.2017.03.002
Abstract:
The aging of non-metallic materials and products was one of the determining factors of the weapons' lifetime.The existing accelerated aging test standards of non-metallic materials are introduced in this article,and the similarities and differences between these test standards are analyzed.The conceptions of the development trends of accelerated aging tests are also proposed.
The aging of non-metallic materials and products was one of the determining factors of the weapons' lifetime.The existing accelerated aging test standards of non-metallic materials are introduced in this article,and the similarities and differences between these test standards are analyzed.The conceptions of the development trends of accelerated aging tests are also proposed.
2017, 47(1):59-61.
DOI: 10.12044/j.issn.1007-2330.2017.01.012
Abstract:
In order to obtain the tightening characteristics of C/C composite material bolt, the tightening torque characteristics of C/C composite material bolt with different structures were studied in this paper. The research can include the variation trend of the torque coefficient K of the bolts in different combinations of gasket material, single nuts and double nuts, scribbling with adhesives and non-scribbling with adhesives. The ultimate torsional resistance of C/C composite material bolt was studied. The results show that the torque coefficient K of the bolts is different from that of the metal bolts. The scribbling with adhesives can obviously improve the clamping force.
In order to obtain the tightening characteristics of C/C composite material bolt, the tightening torque characteristics of C/C composite material bolt with different structures were studied in this paper. The research can include the variation trend of the torque coefficient K of the bolts in different combinations of gasket material, single nuts and double nuts, scribbling with adhesives and non-scribbling with adhesives. The ultimate torsional resistance of C/C composite material bolt was studied. The results show that the torque coefficient K of the bolts is different from that of the metal bolts. The scribbling with adhesives can obviously improve the clamping force.
16 Research Status of Thermal Protection System and Thermal Protection Materials for Aerospace Vehicles
2018, 48(4):9-15.
DOI: 10.12044/j.issn.1007-2330.2018.04.002
Abstract:
With the development of space technology, the aircraft flight speed is much higher and the service environment is even worse. The effective thermal protection system is one of the key systems to ensure the safety of aircraft flight. In this paper, the application status of passive thermal protection system, active thermal protection system and semi-passive thermal protection system on the aerospace vehicles are reviewed. And the application and development of five kinds of thermal protection material in the aerospace field, including metal matrix composites, carbon based materials, ceramic matrix composites, resin matrix composites and aerogel materials are mainly introduced. Finally the future developments of the thermal protection for aerospace vehicles are prospected.
With the development of space technology, the aircraft flight speed is much higher and the service environment is even worse. The effective thermal protection system is one of the key systems to ensure the safety of aircraft flight. In this paper, the application status of passive thermal protection system, active thermal protection system and semi-passive thermal protection system on the aerospace vehicles are reviewed. And the application and development of five kinds of thermal protection material in the aerospace field, including metal matrix composites, carbon based materials, ceramic matrix composites, resin matrix composites and aerogel materials are mainly introduced. Finally the future developments of the thermal protection for aerospace vehicles are prospected.
2017, 47(1):55-58.
DOI: 10.12044/j.issn.1007-2330.2017.01.011
Abstract:
Based on modern filament winding technology, processing property and puzzles are analyzed for the microwave absorbing composites cylinders. For winding layer including absorbers, a technique is adopted, which prepreg is prepared using double rolls for the same slot and double lines sandwich core, and absorbing composites cylinders are manufactured through wet filament winding. The results show the winding rules and the processing parameters can meet cylinders manufacture. The content of absorbers dispersed in the different prepreg well-proportioned can be controlled,and the microwave absorbing performance is excellent.
Based on modern filament winding technology, processing property and puzzles are analyzed for the microwave absorbing composites cylinders. For winding layer including absorbers, a technique is adopted, which prepreg is prepared using double rolls for the same slot and double lines sandwich core, and absorbing composites cylinders are manufactured through wet filament winding. The results show the winding rules and the processing parameters can meet cylinders manufacture. The content of absorbers dispersed in the different prepreg well-proportioned can be controlled,and the microwave absorbing performance is excellent.
2017, 47(2):1-4,13.
DOI: 10.12044/j.issn.1007-2330.2017.02.001
Abstract:
The progress of materials and processings for ablative polymer composite is introduced in this paper. The materials include ablation-resistant matrix resins and reinforcement, the processings include die moldings, tape wraps, layups and resin transfer moldings (RTM).
The progress of materials and processings for ablative polymer composite is introduced in this paper. The materials include ablation-resistant matrix resins and reinforcement, the processings include die moldings, tape wraps, layups and resin transfer moldings (RTM).
19 Ｃｏｍｐａｒａｔｉｖｅ Ｓｔｕｄｙ ｏｎ Ｐｒｏｐｅｒｔｉｅｓ ｏｆ Ｔｈｒｅｅ Ｔ７００ Ｇｒａｄｅ ＣａｒｂｏｎＦｉｂｅｒｓ ａｎｄ Ｔｈｅｉｒ Ｅｐｏｘｙ Ｍａｔｒｉｘ Ｃｏｍｐｏｓｉｔｅｓ
2016, 46(4).
Abstract:
Ｔｈｅ ｔｅｎｓｉｌｅ ｐｒｏｐｅｒｔｉｅｓꎬ ｓｕｒｆａｃｅ ｍｏｒｐｈｏｌｏｇｙꎬ ｌａｍｉｎａｔｅ ｍｅｃｈａｎｉｃａｌ ｐｒｏｐｅｒｔｉｅｓ ａｎｄ ＡＧＳ ｃｙｌｉｎｄｅｒ ａｘｉａｌ
ｃｏｍｐｒｅｓｓｉｏｎ ｓｔａｂｉｌｉｔｙ ｏｆ ＭＴ７００ ｃａｒｂｏｎ ｆｉｂｅｒ ｈａｖｅ ｂｅｅｎ ｓｔｕｄｉｅｄ ｇｒａｄｕａｌｌｙꎬ ｃｏｍｐａｒｅｄ ｗｉｔｈ Ｔ７００－Ａ ａｎｄ Ｔ７００－Ｂ ｃａｒｂｏｎ
ｆｉｂｅｒｓ. Ｔｈｅ ｔｅｎｓｉｌｅ ｓｔｒｅｎｇｔｈ ｏｆ ＭＴ７００ ｈａｓ ｃａｔｃｈ ｕｐ ｗｉｔｈ Ｔ７００－Ａ ａｎｄ Ｔ７００－Ｂ. Ｔｈｅ ｈｏｍｏｇｅｎｅｏｕｓ ｇｒｏｏｖｅ ｏｎ ｆｉｂｅｒ ｓｕｒ￣
ｆａｃｅ ｃｏｕｌｄ ｅｆｆｅｃｔｉｖｅｌｙ ｉｍｐｒｏｖｅ ｉｔｓ ｉｎｔｅｒｆａｃｉａｌ ｐｒｏｐｅｒｔｙ ａｎｄ ｔｅｎｓｉｌｅ￣ｃｏｍｐｒｅｓｓ ｃｏｍｐａｔｉｂｉｌｉｔｙ. Ｔｈｅｒｅｆｏｒｅꎬ ｔｈｅ ｃｏｍｐｒｅｓｓｉｖｅ
ｓｔｒｅｎｇｔｈꎬ ｉｎｔｅｒｌａｍｉｎａｒ ｓｈｅａｒ ｓｔｒｅｎｇｔｈ ａｎｄ ｆｌｅｘｕｒａｌ ｓｔｒｅｎｇｔｈ ｆｏｒ ＭＴ７００/６０３ ａｒｅ ｓｕｐｅｒｉｏｒ ｔｏ Ｔ７００－Ａ/６０３ ａｎｄ Ｔ７００－Ｂ/
６０３. Ｔｈｅ ｍａｘｉｍｕｍ ｆａｉｌｕｒｅ ｌｏａｄ ａｎｄ ａｘｉａｌ ｃｏｍｐｒｅｓｓｉｏｎ ｍｏｄｕｌｕｓ ｏｆ ＭＴ７００/６０３ ＡＧＳ ｃｙｌｉｎｄｅｒ ａｒｅ ａｓ ｈｉｇｈ ａｓ ８７０ ｋＮ
ａｎｄ １０８.２ ＧＰａꎬ ｒｅｓｐｅｃｔｉｖｅｌｙꎬ ｗｈｉｃｈ ｈａｖｅ ｉｎｃｒｅａｓｅｄ ｂｙ １１.５％ ａｎｄ ３３.１％ ｃｏｍｐａｒｅｄ ｔｏ Ｔ７００－Ｂ/６０３. Ｔｈｅ ｒｅｓｕｌｔｓ
ｄｅｍｏｎｓｔｒａｔｅｄ ｔｈａｔ ＭＴ７００ ｃａｒｂｏｎ ｆｉｂｅｒ ｉｓ ｓｕｉｔａｂｌｅ ｆｏｒ ｐｒｅｐａｒｉｎｇ ｌｏａｄ￣ｃａｒｒｙｉｎｇ ｃｏｍｐｏｎｅｎｔ ｉｎ ａｅｒｏｓｐａｃｅ ｓｔｒｕｃｔｕｒａｌ ｃｏｍ￣
ｐｏｓｉｔｅｓ.
