- Volume 45,Issue 1,2015 Table of Contents
>综述
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2015, 45(1).
Abstract:
Thermochromic coating technology is an important technology for spacecraft thermal control subsystem,and it has significant implication for performing multitask and adapting complex thermal environment of futurespacecraft. The paper analyzes demands of thermochromic coating technology for spacecraft thermal control subsystem,and it introduces technology principle and study instance in China and broad for thermochromic coating. Subsequentlydevelopment trend for thermochromic coating technology is summarized, and further directions are proposed. >计算材料学
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2015, 45(1).
Abstract:
The running conditions of the space-borne Stirling convertor is rigorous,such as high temperature andpressure from inner working fluid. To ensure long longevity and high efficiency heat transfer of the heater head, thematerials,structure and so on are need to be analyzed and optimized. In this paper, the structure design principle,analysis,demands for the heater head of space-borne Stirling convertor are introduced. The difficulty of the heater headstructure is also analyzed in this paper. The heater head optimistic design combined with stress analysis produced byboth temperature and pressure were carried out with the aid of commercial finite element method,the finial heater headstructure design was completed and fabricated,the hardware was integrated on the Stirling engine,the heater head performanceis satisfied with the experiment demands. -
2015, 45(1).
Abstract:
Through the study on the effect of carbides on properties of hot work die steels by the Thermo-Calcsoftware, the compositions of a new type heat strength and corrosion resistance steel were designed preliminary. Microstructuresand properties were characterized. The matrix structure of this steel was martensite, in which carbidesdispersed. The tensile strength of this steel was as high as 2 067 MPa at room temperature. The hardness was about50HRC, when tempered at 620℃ for 2 hours,corrosion resistance of the steel was good in NaCl. -
2015, 45(1).
Abstract:
Stress is a universal phenomenon in thin film deposition. It has important effect on structure and performanceof thin film. In order to improve optical and mechanical performance of filters, the stress in ZnS/ Ge opticalthin film and stress control technology are studied by theory and experiments. It is found that ion beam bombardmentand vacuum annealing affect the stress in thin film. The stress in ZnS films is compressive stress. Ion beam assisteddeposition makes the stress uniformity in ZnS films. Vacuum annealing makes compressive stress in ZnS films half ofthe value before annealing. Finite element method analysis results of ZnS/ Ge multilayer thin films show the thermalstress has larger value on edge of thin film and substrate. Thin film has larger deformation on edge. The results showthat ZnS/ Ge multilayer thin film filters have less compressive stress by optimum deposition and different stress films.The average stress is 0. 1 MPa respectively. >新材料新工艺
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2015, 45(1).
Abstract:
Support cylinder is the connector of rocket and satellite. It will reduce the vibration response of satellitethrough improving damping performance of the support cylinder. The support cylinder which is made of T700Scarbon fiber reinforced AG80 resin can not meet the damping requirement at room temperature. This paper expoundedtwo methods to increase its damping performance. The first was to select the modified 861340 as the matrix of thecomposite. The result showed that when the content of 861340 was 23%, the damping performance was the best. Thesecond was to use the piecewise layer method which resulted from the technology of Constrained Layer Damping. Twokinds of support cylinder were made as comparative experiments. 1# applied AG80 resin as matrix while 2# appliedmodified 861340 and the piecewise layer method. Compared with 1#, the vibration response of 2# dropped 60. 5% inthe longitudinal vibration experiment. It was 20. 7% lower than 1# in the transversal vibration experiment. -
2015, 45(1).
Abstract:
Shape memory epoxy resin of PU/ TDE-85 was prepared by using tetrahydromethyl-1,3-isobenzofurandione(METHPA) as a curing agent. The characteristics of the blends were investigated by tensile test, SEM,DMA and FTIR. Blends with varying proportions of PU/ TDE-85 were studied for their mechanical properties, thermodynamics,glass-transition temperature and shape memory properties. The test results show that the toughness of epoxyresin was improved by adding PU. And the glass-transition temperature also decreased accordingly. Moreover, thematerial exhibited a good shape memory performance, the shape recovery and the shape fixity of this material can achieve96% and 100%, respectively -
2015, 45(1).
Abstract:
Toughening of a diglycidyl ether of bisphenol-A(E-51)-based epoxy resin and TDE-85 with liquidcarboxyl-terminated butadiene acrylonitrile(CTBN) copolymer has been investigated in this research. Shape memoryepoxy resin of CTBN/ EP was prepared by using tetrahydromethyl-1,3-isobenzofurandione(METHPA) as a curing agent.The characteristics of the blends were investigated by tensile test, SEM, DMA and FTIR. Blends with varyingproportions of CTBN/ EP were studied for their mechanical properties, thermodynamics ,glass-transition temperatureand shape memory properties. The test results show that the toughness of epoxy resin was improved by adding CTBN.And the glass-transition temperature also decreased accordingly. Moreover, the material exhibited a good shape memoryperformance, the shape recovery and the shape fixity of this material can achieve 100% and 97%, respectively. -
2015, 45(1).
Abstract:
In this report, details on the toughening of epoxy matrix composites by the polysulfone was describedto be adapted to great-distortion conditions. The mechanics capabilities thermal performance and micro-morphologywere investigated by kinds of analysis method. The results showed the composite material offered good compabilities,such as flexural strength of 1 206. 3 MPa, interlayer shear strength of 111. 5 MPa,interlaminar fracture toughness of 1108. 9 J/ m2, as well as, the materal worked well at 130℃. The curling test is succusful with the curvature radius lessthan 20 cm, proving the great performance. -
2015, 45(1).
Abstract:
To investigate the influence of thermal environment in orbit on the adhesive properties of J-47Cstructural adhesive, Tg and weight-loss temperatures of J-47C were acquired by DMA and TGA. Tensile lap-shearstrength of the adhesive at different temperatures, before and after thermal shock, and after vacuum thermal cycle environmenttest was measured. The results show that the tensile-strength was of slightly changes after these environmenttests. The J-47C structural adhesive can achieve the requirements of the special temperature environments announcedby the usage of spacecrafts. -
2015, 45(1).
Abstract:
Based on the arts and crafts principles of electronic parts, the solidification processes of MD-130 adhesivewere systematically investigated and the space adaptability was valued. Results showed the optimal solidificationparameters are on 150℃ for 60 minutes, which showed up to 18 MPa in shear strength. Thermal shock and lowdensity particle radiation led to better solidification and mechanical performance. However, overdosed radiation triggeredthe degradation, which made the mechanical strength reduced. After the environment experiments, MD-130adhesive indicated good properties, which can meet the designing requirements. -
2015, 45(1).
Abstract:
A two-component epoxy adhesive KH-A has been developed,to satisfy the needs for parts adhesion ofthe solar array drive assembly(SADA) of satellite under the adverse space environment. The Tg of the cured KH-A isas high as 143℃. The lap shear strength for carbon steel joints bonded with KH-A adhesive is 23. 0 MPa at 25℃ and20. 9 MPa at 125℃. In addition,the cured epoxy exhibits good γ-ray radiation resistance. After a radiation dose of 1×108 rad in γ-ray environments,the electrical breakdown strength of cured KH-A is 25. 2 kV/ mm,which is even higherthan that of the samples before radiation(20. 1 kV/ mm). At last,the cured KH-A possesses low outgassing propertiesin vacuum with the total mass loss(TML) value of 0. 97% and collected volatile condensable materials(CVCM) valueof 0. 01%. Properties of adhesives KH-A can satisfy the application requirement of products. -
2015, 45(1).
Abstract:
We investigated the thermal radiation properties of one type of thermal control coatings with stainlesssteel as substrate under thermal cycles. The rapid thermal cycles ranged from -196℃ to 900℃. Solar absorptance,hemispheric emittance and SEM were measured for analyzing the thermal radiation properties of the coatings. The resultsshow that solar absorptance of the thermal control coating had little change under thermal cycles, while the cycleshad obvious effect on hemispheric emittance of the coatings, which increased from 0. 57 to 0. 72, and finally the hemisphericemittance was steady at 0. 75. According to SEM, the surface of the coating was better crystallized under thermalcycles, and the grain size on the surface of the coating was bigger. The difference of microstructures on the surfacesof coatings leads to the changes of thermal radiation properties. -
2015, 45(1).
Abstract:
In this study,PI/ MoS2 lubrication coating was deposited on titanium alloy. This coating was exposedto a highly aggressive humidity durability test, test conditions were 70℃,98% relative humidity for 27 days. Theeffects of hygrothermal on the chemical structure of the binder were studied by ATR-FTIR and FTIR. And the changesof surface chemical components were investigated by XPS. The friction and wear behaviors of the coatings after hygrothermaltest were studied by ball-on-disc tribometer. Pull off adhesive tester was used to evaluate the adhesionstrength of the coating. The results indicated that the treatment caused the PI resin at the surface of the coating to becorroded, part of the resin in the coating hydrolyzed and the MoS2 at the surface to be oxidized. The wear life decreased13% in vacuum and 16% at atmophere environment. The friction coefficient increased more greatly in the atmosphericenvironment. Adhesion of the films decreased slightly. -
2015, 45(1).
Abstract:
To solve the ceramic substrate metal film-integrated component of laser micro-machining accuracyproblems,under atmospheric environment,nanosecond pulsed laser effects,of the Cu ( Ni80Cr20 ) -Al2O3 compositebody were studied experimentally of film/ substrate on interface separation mechanism. The results show that: when laserablation Cu, laser spot effected region can be completely gasified to give a more smooth image,but when ablationthe Ni80Cr20,laser spot effected region first nitride,the nitride layer is then peeled off leading edge of the rough ablationpattern. Gaussian distribution of the energy of the laser spot,making Ni80Cr20unevenly nitrided,is the main reasonaffecting the precision of the ablation. Laser wavefront diffraction transform technology is employed, making the spotfrom the Gaussian distribution of energy into energy distribution is flattened. When the laser energy is greater than 5． 4mJ,the Ni80Cr20 layer thickness 4 μm uniform nitrided,then peeled,realized Ni80Cr20 -Al2O3 assembly precision,withoutdamage to the substrate ablation. -
2015, 45(1).
Abstract:
Tungsten doped hydrogenated diamond-like carbon films ( W -C: H) were deposited on 40Cr,9Cr18, GCr15, TC4 and LY12 substrates with the unbalanced magnetron sputtering method. The surface morphology,microstructure, microhardness, adhesion, and tribological properties of the films were characterized by scanning electronmicroscope(SEM), Raman spectroscope, nano-hardness/ scratch tester, and ball-on-disk tribo-meter respectively.The effect of different substrate materials on tribological properties of the deposited films were studied under dryfriction and PEPE grease lubrication conditions. Films quality testing results shows the films with 1 μm thickness havetypical diamond-like structures and exhibit high hardness 11. 56 GPa, elastic modulus 128. 34 GPa, and good adhension645 mN. Tribological test results show that the friction coefficient and wear rate of the films deposited on severalmetal substrates are significant different in dry sliding, and the substrate effect is smaller under grease lubrication.Compared with the friction results in dry sliding,the wear under grease lubrication can reduce 60% to 75%. The WC:H films deposited on 9Cr18 and 40Cr substrates provide the minimum wear rate of 1. 71×10-7 mm3 / (N·m) and 4.55×10-8 mm3 / (N·m) in dry sliding and grease lubrication respectively. -
2015, 45(1).
Abstract:
Ti53311S alloy was successfully joined by TLP bonding with Cu filler metal. The interfacial microstructurewas characterized by SEM and EDS. Effects of TLP bonding temperature and holding time on the joint microstructureand mechanical properties were investigated in details. The results showed that the typical interfacial microstructurewas Ti53311S/ β-Ti/ Ti,Cu(Sn) intermetallic compound/ β-Ti/ Ti53311S. The mutual diffusion degree betweenbase metal and Cu interlayer increased with the rise of TLP bonding temperature and increase of holding time,which caused the increase of the joint width and reduction of compound in the joint. The degree of diffusion affectedthe strength of the bonding greatly. The tensile strength of joints increased at first gradually and then tended to be stableat room temperature. The highest tensile strength, which was achieved at the bonding temperature of 980℃ holdingfor 20 min, was 899 MPa. -
2015, 45(1).
Abstract:
The influence of pin length on the mechanical properties of dissimilar Al5754/ Al6111 friction stirspot welds has been investigated. The mechanical properties show no obvious changes when the pin length increasesfrom 1. 6 mm to 2. 0 mm. However, the mechanical properties of spot welds improve a lot when the pin length increasesto 2. 2 mm, which is the basically caused by highly serrated hOOK profiles. >计算材料学
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2015, 45(1).
Abstract:
Joining samples of carbon/ carbon composites (C/ C composites) and Ni based high temperature alloy(GH600) were fabricated by vacuum brazing with the powder of BNi68CrWB as the interlayer material. The mechanicalproperties and microstructure of the joints between C/ C composite and GH600 were investigated by scanning electronmicroscopes and universal material testing machines. The results show that the joining of C/ C composites to Nibased high temperature alloy is successfully achieved by vacuum brazing process. The fracture of the joint occurs inthe C/ C composites. The shear strength at high temperature of the brazed joints rapidly decreases above 700 ℃. >新材料新工艺
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2015, 45(1).
Abstract:
In this experiment selected SnPb, InPb and InPbAg three solders were selected to solder the AuNi9brush wires which serve in the spacecraft control system. The mechanical properties, the fracture morphology, microstructuresand the composition of compound phases of soldered joints were compared, thus exploring the impact of theimproved solder on the formation of the compound layer in soldered joints. The results show that there generate the obviouscompounds in AuNi9 soldered joints near the gold alloy side using SnPb solder, mainly including AuSn4, Au-Ni2 Sn4 and Ni3Sn4 compound phases. InPb solder can significantly reduce the joints brittleness, and there generate nointermetallic compounds in the joint region. While the InPbAg solder can not only protect the silver layer of copperwires, but also could produce the tiny strengthening phase, i. e. , Ag2In in the joint to enhance the joint shearstrength. >测试分析
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2015, 45(1).
Abstract:
A screw failure was found when the line joints were taken apart. This paper records the results ofmacroscopic observation, the microscopic observation and measurement, the observation of the screw, and the materialtests of the failure part, such as hardness test and metallographic analysis. The results indicated a seizure of thethreads on the line joints which originated in an adhesive wear, the type of which causes most severe damage. Combinedwith the assembly mechanism of the screw thread connection, it is concluded that using the same material is theinternal cause of the adhesive wear of the line joint. Too little interspaces between the joint which leading the screwthread of the joint broken during installation and the remainders accumulate made the nut deflexion is the main causeof the adhesive wear of the line joint. -
2015, 45(1).
Abstract:
A gear of an aerial system broke during the unfolding test. A series of test results show that the metallurgicalstructure, the chemical composition, and the mechanical properties of the material all meet the demands of relatedstandards. Via scanning electron microscope, the micro appearance of the fracture has been observed. Evidentfatigue strips were found in the crack characters. Combined with test process of the aerial system, it is concluded thatthe failure mechanism is that the fatigue broken of individual teeth caused the plastic overload fracture of other teethand finally lead to the failure of the whole link connection. >工程实践
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2015, 45(1).
Abstract:
A film substrate appear abnormal phenomenon of transparent material precipitation in the sinteringprocess, seriously affecting the strength of bonding. Through visual inspection, SEM analysis and spectrum analysis,the main components of transparent material precipitated was determined as glass. After analysis, the thickness of theprinting exceeded is the main reason for the abnormal substrate sintering, However, decrease the thickness of theprinting will affect product performance
