最新刊期
卷 30 ， 期 3 ， 2010
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- 摘要：Interfacial reactive layers between Ti-47Al-2Cr-2Nb-xTiB2 alloys and Al2O3 ceramic molds were fabricated.With the help of SEM（scanning electron microscope）,EDS（energy dispersive spectrum）,XRD（X-ray diffraction）and micro-hardness measurements,interfacial reactive behaviors between three kinds of TiAl based alloys and Al2O3 ceramic molds were analyzed comparatively.The results reveal that the interfacial reaction of TiAl alloy melt with Al2O3 ceramic molds can be effectively relieved by adding TiB2.The interfacial reactive mechanism was characterized by an imbalanced diffusive chemical reaction,and the corresponding reaction model is established.关键词：TiAl Based Alloy;TiB2;Investment Casting;Interfacial Reaction
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发布时间：2023-12-18 - 摘要：Deformation behavior of carbon nano-tubes reinforced magnesium matrix composites was simulated by a simplified model based on the FEM（finite element method）to understand the strain and stress distribution in the matrix and reinforcement as well as effects of interface on mechanical properties of the composites,and stress transferring and fracture mechanism of carbon nao-tubes with the magnesium matrix alloy were expounded.The results reveal that the whole carbon nano-tube exhibits homogeneous stress distribution,however,the stress aggregation occurs in interface at axial direction to some extent.Remarkable stress aggregation can be observed in the contacted location of two-end face of matrix with carbon nao-tubes,where stress distribution exhibits flamboyance,decreasing from the center to the outer,while the stress distribution in the other location of the matrix alloy is very homogeneous.The fracture of the composites begins at the interface,and the fracture mechanism is characterized by interfacial debonding,which is accordant with the experimental ones.关键词：Carbon Nano-tubes;Magnesium Matrix Composites;Finite Element Method
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发布时间：2023-12-18 - 摘要：There exists coarse skeleton-like Ni2Si phase and serious dendrite segregation in as-cast microstructure of Cu-3Si-2Ni alloy,which greatly deteriorates the formation behavior of the ingot.Homogenizing annealing treatment was conducted to improve the formation ability of the alloy at 850950℃ for 28 h.The results indicate that plasticity of the alloy is significantly improved as a result of the elimination of major dendrite segregation in the as-cast alloy after homogenizing annealing at 900℃ for 4 h.Meanwhile,fracture mechanism of the alloy is characterized by from quasi-cleavage fracture combining with partial shearing fracture at as-cast state into micro-hole concentrating ductile fracture at homogenizing annealing state.关键词：Copper Alloy;Homogenizing Annealing;Microstructure and Properties;Fracture
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发布时间：2023-12-18 - 摘要：TiB2 particle reinforced aluminum matrix composites were synthesized by in-situ reaction,and the formation mechanism of reinforcement in the composites was analyzed by XRD（X-ray diffraction）,and three key factors influencing solidification process were analyzed by measuring solidified dynamic curves of the composites,meanwhile,tensile behavior of the composites was observed by the SEM（scanning electron microscope）.The chemical reactive formula is described as 3TiO2 +10Al+3B2O3→5Al2O3 +3TiB2 with molar ratio of 1 of TiO2 via B2O3.The solidification process is mainly controlled by distribution of particles in the matrix,molar ratio of TiO2 via B2O3 and reactive temperature.The strengthening mechanism is characterized by dispersed enhancing from TiB2 particle and fine-grain enhancing resulting form TiB2 as nuclei substrate.Fracture mechanism of the composites is characterized by micro-hole concentrating toughening failure from TiB2 particle pulled out.关键词：In-situ Synthesis;Aluminum Matrix Composites;Fabrication Process;Solidified Dynamic Curves;Tensile Behavior
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发布时间：2023-12-18 - 摘要：Effects of introducing ultrasonic temperature on microstructure and properties of Mg-Zn-Er alloy prepared by high intensity ultrasonic melt treatment were analyzed.The results indicate that as-cast microstructure of the alloy is converted from coarse dendrite into uniformly distributed fine spheroidized grain with increasing in introducing ultrasonic temperature in condition of ultrasonic time for 100 s and ultrasonic power of 600W,in which an optimized temperature is 718℃.The grain with desirable size and uniform distribution and roundness in Mg-5Zn-2Er alloy treated by ultrasonic at 718℃ can be observed,and tensile strength and elongation reach 199.6MPa and 11.6% at room temperature,respectively,exhibiting the maximum value,while tensile strength exhibits the minimum values at high temperature.关键词：High-intensity Ultrasonic;Magnesium Alloy;Microstructure;Properties;Ultrasonic Cavitation
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发布时间：2023-12-18 - 摘要：Behaviors of cyclic stress response and cyclic deformation,fatigue life as well as fracture mechanism were identified for as-extruded AZ31 magnesium alloy through total-strain-amplitude controlled fatigue testing and analysis on fracture surface of fatigued specimens.The results indicate that the as-extruded AZ31 alloy exhibits significant cyclic strain hardening and stretch-compression asymmetry in cyclic deformation,and the relationship between elastic strain amplitude,plastic strain amplitude and reversal to failure can be described by the Basquin and Coffin-Manson equations,respectively.In addition,it is found that fatigue cracks are generated and propagated in a transgranular mode.关键词：Magnesium Alloy;Elastic Strain Amplitude;Plastic Strain Amplitude;Fatigue Fracture;Cyclic Stress Response;Cyclic Deformation;Fatigue Life;Fatigue Cracks
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发布时间：2023-12-18 -
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- 摘要：Taking a coupling flange as an example,we described design processes from parts,castings to casting mould on the basis of the Pro/E software.The part modeling should take various processing modelings into account during product design,especially a certain sequence and some kills followed in the parts and three-dimensional modeling process in order to ensure the design of the castings and casting mould smoothly.Processing model should be firstly constructed before modeling the casting mould,in which some technological parameters such as core print and drafting angle are set.Then process model was used to separate the outer mould from the core print,which could decrease the potential errors during individual modeling,improving the precision of the mould and shortening the market period of the product.关键词：Housing Components;Casting Mould;Drafting Angle;Pro/E Software
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发布时间：2023-12-18 - 摘要：Thermal stress which is difficult to measure easily occurs in electro-slag casting steel ingot due to great difference in temperature at different position.Equivalent stress fields in the steel ingot at different slag pool depths were simulated by the ANSYS software,and the quadratic function relation between the maximum equivalent stress and the depth of slag pool was presented.The simulated results are well in agreement with practical ones,showing the availability of the model.关键词：Electro-slag Casting;Equivalent Stress Field;Slag Pool Depth;Numerical Simulation
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发布时间：2023-12-18 - 摘要：The substitution of die casting magnesium alloy for aluminum alloy in wheel products and its measures were analyzed by taking transmission pulley as a sample.Based on the analysis of service life and failure conditions,the structure of magnesium alloy transmission pulley was redesigned by the stress analysis of the original structure and topologic optimization analysis.The results reveal that service stress of the optimized magnesium alloy transmission pulley is decreased from 40.5MPa to 24.7MPa,greatly lower than ultimate fatigue strength.In addition,the absence of die casting defects in the pulley can be observed due to the realization of sequential solidification during filling process.Compared with those of aluminum alloy ones,the weight and cost of magnesium alloy transmission pulley are decreased by 43.8% and by 34.5%,respectively.关键词：Magnesium Alloy;Wheel;Finite Element Analysis;Topologic Optimization
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发布时间：2023-12-18 - 摘要：Commercial aluminum profiles database which include light-loading,middle-loading and heavy loading aluminum profiles with various sectional areas and flat profile as well as universal profiles was developed in the SolidWorks welding plug-in.Through visualizing a practical object,process of establishing the database in the plug-in was described in detail,and application of the database in the welding plug-in was introduced.Through establishing commercial aluminum profiles database,SolidWorks user could shorten designing time and improve efficiency.关键词：Commercial Aluminum Profiles Database;SolidWorks;Welding Plug-in
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发布时间：2023-12-18 - 摘要：Semi-solid slurry preparation technologies and mechanism of microstructure formation were surveyed.A novel method for semi-solid slurry preparation that is self-inoculation method（SIM）was presented,in which self-inoculator（the same composition to that of the alloy melt）was introduced into the melt,and then the melt was poured into a fluid director for further inoculation.Solid-liquid mixed slurry with non-dendritic primary phase can be obtained by controlling alloy melt temperature and partial under-cooling to create amounts of nuclei,and by nucleating with self-inoculation nuclei to generate nuclei with a small critical radius for grain growth based on local under-cooling,flow scouring which enhanced self-inoculation effects and promoted grain multipilication and inhibited grain growth.AM60 alloy was used to conduct series of experiments.The results reveal that semi-solid slurry with approximately 51μm in average size,uniform and non-dendritic primary phase is observed with 11% self-inoculator addition after the melt is processed by SIM at 650℃.关键词：Semi-solid State;Self-inoculation;Slurry Preparation;AM60 Alloy
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发布时间：2023-12-18 - 摘要：A new technology for metal matrix composites——liquid infiltration-forging densification under pressure was proposed based on the analysis of some traditional methods.And the Al2O3f·SiCp/Al composites were prepared by the methods.Microstructure and performance testing show that interface bonding of the composites exhibits metallurgical bonding with compact structure and excellent properties.The typical parts——loading wheel was produced by the method,realizing the liquid forging integral forming between wear-resistant composites ring and main body.关键词：Local Reinforcement;Metal Matrix Composites;Liquid Forging;Integral Forming
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发布时间：2023-12-18 - 摘要：Aiming at structural features of motorcycle brake clamp body,based on 2D model designed by the Auto CAD,visualization of the model was developed with the help of 3D-MAX software on established 3D model platform by Pro/E software,and flow field and temperature field in the parts during filling process were simulated by the JSCast software.The simulated results are well in agreement with the experimental ones,so potential defects and their position in the parts were predicted by the model,and processing design was examined by the JSCast software with the completion of optimized design.Solidification process was obviously improved as a result of uniform distribution of temperature field in wall thickness by setting core at thick position of the parts,eliminating the hot spot in thick position and improving the quality of the parts.关键词：Squeezing Casting;Filling;Solidification;Visualization;Numerical Simulation
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发布时间：2023-12-18 - 摘要：Injection punch heads as a key assistant part in die casting machine,its service lif directly affected the manufacturing efficiency and cost.A new intermittent cooling method was presented for the injection punch heads made by HT200.Effects of tolerance and cooling time on service life of the injection punch heads were analyzed.The results reveal that service life of the heads is closely related to the tolerance and cooling time.The punch heads exhibits a longer service life with tolerance at 0.080.16 mm.Furthermore,service life of the HT200 punch heads can reach up to 1600 times under the optimized tolerance of 0.080.16 mm and cooling time of 35 s.关键词：Die Casting;Injection Punch Heads;Service Life;Cooling Water;Tolerance
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发布时间：2023-12-18 - 摘要：Microstructure and mechanical properties of AZ91D shock absorption tower and AM60 shock absorption tower produced by vacuum die casting were analyzed comparatively,and effects of heat treatment were examined.Microstructures of both AZ91D and AM60 magnesium alloy parts are composed of α-Mg matrix and β-Mg17Al12 phase,in which β-Mg17Al12 phase disappears after solid solution and it is precipitated as discontinuous phase after aging treatment.Although both AZ91D and AM60 alloy parts can be strengthened by heat treatment,strengthening effect on AZ91D alloy parts are superior to that on AM60 alloy parts.In addition,gas hole in the parts can be effectively eliminated,however,shrinkage defects can not completely eliminated by vacuum die casting.Mechanical properties of the vacuum die casting parts can be greatly improved after heat treatment.关键词：Magnesium Alloy;AZ91D Alloy;AM60 Alloy;Vacuum Die Casting;Heat Treatment
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发布时间：2023-12-18 - 摘要：A typical thin-walled aluminum alloy components was successfully manufactured by investment casting combining with counter gravity casting on the basis of optimizing filling velocity and pouring temperature of the liquid alloy.关键词：Counter Gravity Casting;Investment Casting;Thin-walled Aluminum Alloy Castings
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发布时间：2023-12-18 - 摘要：Lower shelling performance of sol silicate mold shell could directly affect the product efficiency and surface quality of complicated investment castings.Shelling performance can be improved by employing mixed coating in transition layers of mold shell,greatly improving shelling efficiency.High temperature strength of shell mold is slightly affected due to grain precipitation at high temperature and phase transformation at low temperature of molten quartz in the mixed coating,and residual strength can be greatly decreased as a result of volumetric contraction of phase transformation in molten quartz during solidification,which obviously improves shelling performance.The process and other assistant measures improving shelling performance were described.关键词：Shelling Performance;Sol Silicate;Investment Casting
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发布时间：2023-12-18 -
- 摘要：Ultrasonic field was introduced into 7050 aluminum alloy melt in the semi-continuous casting to investigate effects of ultrasonic treatment on the quality of 7050 ingot.The results reveal that quality of 7050 ingot is greatly improved by introducing ultrasonic field,in which grain size is refined and is equiaxed with decreasing in gas hole,leading to increasing in tensile strength and restraining in crack.The experimental results verify that ultrasonic filed can effectively improve the quality of 7050 aluminum alloy ingot,which provides a reference to industrial production of large 7050 aluminum alloy ingot.关键词：7050 Aluminum Alloy;Ultrasonic Field;Degassing;Grain Refinement;Crack
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发布时间：2023-12-18 - 摘要：YZM cylindrical bridge bearing is a new kind of railway bridge cast steel bearing.EPC have many advantages in producing railway bridge cast steel bearing.Key processing parameters and product conditions as well as ways for assuring qualified carbon steel casting by EPC were presented,which could decrease cost by 5%20%.关键词：EPC;Steel Bearing;Cast Steel
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发布时间：2023-12-18 - 摘要：SiC particle reinforced A356 aluminum matrix composites with 15% in mass fraction was prepared by stirring casting,and prepared composites were deformed by hot extrusion process.Microstructure and mechanical properties of the prepared composites were investigated by OM（optical microscope）,SEM（scanning electron microscope）and tensile testing.The results show that,SiC particles are distributed uniformly in the alloy matrix,and there exists the enrichment of Si atoms in the interface of SiC/Al.After hot extrusion deformation,casting defects such as porosity are distinctly decreased,resulting in the great improvement of the composites density,meanwhile,directional distribution of SiC particles along the direction of the metal plastic flowing can be observed with the increase of uniformly dispersed SiC particle.After 535℃/5 h solid solution +180℃ /5 h aging treatment,the mechanical properties of hot extruded composites in which approximately 200 nm precipitates with dispersed distribution are observed can reach 370MPa in tensile strength,225MPa in yield strength and 5.3% in elongation.Fracture mechanism of SiCp/A356 aluminum matrix composites is characterized by plastic fracture of matrix alloy and SiC particle fracture.关键词：Aluminum Matrix Composites;Stirring Casting;Hot Extrusion;Microstructure;Mechanical Properties
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发布时间：2023-12-18 - 摘要：Effects of holding treatment on microstructure and properties of B4C/Al composites were investigated to decrease Al content and increase ceramic phase content as well as improving properties of B4C/Al composites prepared by pressure-less infiltration method.The results reveal that the prepared composites are composed of Al,B4C and Al3BC phases.With holding treatment,Al and B4C contents are effectively decreased while Al3BC and AlB2 phases are obviously increased in the composites.Hardness,compression strength and bending strength of the composites are greatly improved as a result of obviously decreasing in Al content and greatly increasing in ceramic phase after holding treatment.Desirable microstructure and properties can be observed in the composites with holding at 850℃ for 24 hours.关键词：B4C/Al Composites;Holding Treatment;Microstructure;Properties
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发布时间：2023-12-18 - 摘要：Thixo-compression behavior and microstructure of SiCp/Al alloy matrix composites were investigated with the help of Gleeble-1500 thermal-mechanical simulator under different deformation temperatures and different deformation rates.It is found that,with increasing in strain,compressive stress of the composites is firstly increased rapidly,then decreased rapidly,and at last increased slowly.In addition,with decreasing in deformation temperature or increasing in deformation rates,compressive stress is increased in semi-solid composites.After compressive deformation,more small SiC particles with average size less than 20μm and approximately 55% in volumetric fraction are mainly not distributed in severe deformation zone but in free deformation zone,which shows that high SiC zone can be created from separation of liquid-solid phase by semi-solid thixo-compression,meeting the requirements of electronic package materials.
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发布时间：2023-12-18 - 摘要：Effects of different Al-5Ti-1B master alloy additions on microstructure and mechanical properties of AZ31 magnesium alloy were investigated.It is found that microstructure and mechanical properties of the AZ31 magnesium alloy are greatly improved with Al-5Ti-1B master alloy addition,and desirable microstructure and properties can be observed in the alloy with 0.5% Al-5Ti-1B addition,where the minimum average grain size that is approximately 30% of average grain size of AZ31 alloy is observed and tensile strength and elongation reach up to 184MPa and 8.14%,respectively.Improvement of microstructure and properties of AZ31 magnesium alloy is related with free Ti and TiB2 particles in Al-5Ti-1B master alloy.关键词：AZ31 Magnesium Alloy;Al-5Ti-1B Master Alloy;Mechanical Properties;Microstructure
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发布时间：2023-12-18 - 摘要：Effects of the Mn and Zr elements on microstructure,mechanical properties and wearing resistance of Ti based TMA alloy（Ti-11.3Mo-6Zr-4.3Sn）for orthodontics were investigated by optical microscope（OM）,XRD（X-ray diffraction）,digital micro-hardness tester,abrasive testing machine,SEM（scanning electron microscope）.The results reveal that substitution of element Mn for Mo can not change phase constituent in TMA alloy,however,a little of α’’ phase can be observed after quenching treatment.ω phase can be created in as-cast microstructure of the TMA alloy with increasing in Zr content,which is transformed into β phase after quenching.Hardness of the TMA alloy is increased and elastic modulus is decreased,and wearing mechanism of the TMA alloy is characterized by abrasive wear and coherent wear,and abrasive wear behavior is improved and coherent wear is deteriorated with substitution of Mn for Mo and the increase of Zr content.关键词：Alloying Element;Beta Ti Alloy;Young’s Modulus;Wearing Resistance
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发布时间：2023-12-18 - 摘要：Compound modification of hypereutectic Al-Si alloy was conducted by adding P+RE.The results indicate that P+RE compound modification has excellent effects on both primary Si and eutectic Si phases.Rosette primary Si size is greatly refined with the passivation of edges,and eutectic Si phase is converted from acicular structure into short-rod ones.The modification mechanism of P+RE on hypereutectic Al-Si alloy was described.关键词：Hypereutectic Al-Si Alloy;P+RE Modification;Microstructure;Modification Mechanism
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发布时间：2023-12-18 - 摘要：The homogeneous Al-Pb monotectic alloys were successfully prepared by a sloping plate method in which monotectic alloys were heated over the miscible temperature and then poured on sloping plate by employing the chilling effects resulting in the rapid decrease of temperature of liquid alloy.Meanwhile,solidification process of monotectic alloy was expounded.The results show that chilling effects of sloping plate can make the Stokes velocity and the Migration speed of Pb-rich phase to act each other to cancel out,which plays a significantly positive role in the homogeneous distribution of immiscible Al-Pb in cooling slope.Then the homogeneous and dispersive distribution of the Al-Pb monotectic alloys was obtained by cooling liquid metal in permanent mold at room temperature.关键词：Monotectic Alloys;Al-Pb Alloy;Sloping Plate;Solidification Process
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发布时间：2023-12-18 - 摘要：Effects of Cr on microstructure and precipitation process of Mg-10Zn-2Al-1Cu alloy were investigated by SEM（scanning electron microscope）and XRD（X-ray diffraction）.It is found that Cr can refine the microstructure of the alloy by partly brokening the network structure of β-Mg17Al12 phase,resulting in the dispersed precipitation of ternary τ-Mg32（Al,Zn）49,AlMg4Zn11,CeCuAl3 phases and Al4Cu9 particle and creation of CrSb2 phase.Evolution of microstructure of the alloy during aging deposition is as follows:supersaturated solid solution→segregation of solute atoms→an vermiculate orderly distributed phase→the transition phase→（short）rod-shaped or granular stability.Cr can accelerate atomic segregation and nucleation rate at early aging and increase the stability of precipitates as well as inhibiting the growth of precipitates at latter aging.关键词：Cr;Mg-Zn-Al Alloy;Precipitation;Aging
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发布时间：2023-12-18 - 摘要：Protective effects of FKS mixed cover gas on molten magnesium alloy were investigated systematically.The results illustrate that FKS can act well as protective gas during melting process.Desirable protective effects can be realized in the molten magnesium alloy with 0.006%FKS at 640700 ℃ in condition of airtight furnace body with excellent airtightness.In additim,Better protective results can be obtained with 0.01% FKS concentration in a simulated die casting condition.Formed protective film is mainly composed of MgF2,and the thickness of the film is 3050μm by SEM observation.关键词：Magnesium Alloy;Ignition-proof;FKS
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发布时间：2023-12-18 -
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- 摘要：Aluminum bronze matrix braking pads were fabricated by powder metallurgical sintering methods.Effects of sintering parameters on properties of the materials were investigated.The results reveal that sintering process is a dominant factor influencing the density and properties of materials.The optimized sintering parameters are as follows:sintering temperature of 910960℃,sintering pressure of 3MPa,holding time of 14 h.The repressing and resintering can improve the density and frictional properties.Density and properties of the materials can further be improved by sintering with mould and greatly increasing the pressure after holding temperature.关键词：Brake Pad;Aluminum Bronze;Sintering;Density
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发布时间：2023-12-18 - 摘要：Origination of crack and gas hole in anode mould produced by high pure copper cathode from induction furnace was analyzed,and countermeasures were presented,which provided a reference for the following casting process.关键词：Anode Mould;Crack;Gas Hole
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发布时间：2023-12-18 - 摘要：Effects of B addition on the microstructure and properties of HSn70-1 alloy containing proper Ce were investigated by means of optical microscope（OM）,tensile testing,scanning electron microscope（SEM）,static corrosion testing and X-ray diffraction analysis.The results reveal that mechanical properties and corrosion resistance of HSn70-1 alloy can be improved obviously by adding 0.10%Ce and 0.03%B.Although B addition has little effects on the refinement of HSn70-1 alloy,0.03%B can make second phase uniformly and dispersedly distribute in the alloy.关键词：Ce;B;HSn70-1;Mechanical Properties;Corrosion Resistance
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发布时间：2023-12-18 -
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