Thermal Stability of Cryomilled Mg Alloy Powder

2017 ◽  
pp. 225-233
Author(s):  
Dikai Guan ◽  
W. Mark Rainforth ◽  
Joanne Sharp ◽  
Junheng Gao
Keyword(s):  
Thermal Stability ◽  
Alloy Powder ◽  
Mg Alloy ◽  
Thermal Stability Of

Grain Refinement of an Al-Cu-Mg Alloy by Microalloying and Common Thermo-Mechanical Treatment

2007 ◽  
Vol 546-549 ◽  
pp. 917-922
Author(s):  
Bao Lin Wu ◽  
Gui Ying Sha ◽  
Yi Nong Wang ◽  
Yu Dong Zhang ◽  
Claude Esling
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Mechanical Treatment ◽  
Grain Structure ◽  
Mg Alloy ◽  
Ultrafine Grain ◽  
Fine Grain ◽  
Thermo Mechanical Treatment ◽  
Ultrafine Grain Structure ◽  
Thermal Stability Of

Heavy deformation plus micro alloying could be an effective way to obtain ultrafine grain structure of metals. In the present work, an Al-Cu-Mg alloy was microalloyed with Zr to obtain homogeneous precipitates and then heavily deformed by conventional forging at high temperature. The possible refining processing routes were studied and the superplasticity behaviors of the alloy was investigated. Results show that the micro alloyed alloy can be stably refined to 3-5μm under conventional processing routes. The Al-3Zr precipitates act both as additional sites to enhance recrystallization nucleation rate and pins to impede grain growth to increase the thermal stability of the fine grain structure. However, as the Al3Zr precipitates remains along grain boundaries, the superplastic capability of the material is not high. At 430°C with 1×10-4S-1 strain rate, the elongation obtained was 260%.

scholarly journals STUDY OF PROPERTIES OF DIFFUSION-HARDENING COMPOSITE SOLDER GASN-CUSN-MO

2020 ◽  
pp. 722-730
Author(s):  
Владимир Михайлович Скачков ◽  
Лилия Александровна Пасечник ◽  
Сергей Павлович Яценко
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Equilibrium State ◽  
Alloy Powder ◽  
Sharp Increase ◽  
Composite Solder ◽  
Molybdenum Powder ◽  
Inert Component ◽  
Order Of Magnitude ◽  
Thermal Stability Of

В статье обсуждается возможность регулирования свойств диффузионнотвердеющего припоя (ДТП) на основе легкоплавкого сплава галлий-олово и твердой компоненты состоящей из порошка сплава медь-олово посредством введения инертного порошка металлического молибдена и термической обработки. Оценена микротвердость и термическая устойчивость композиционных диффузионнотвердеющих припоев. Показано, что повторная термическая обработка при высоких температурах способствует переходу припоя в равновесное состояние, при этом происходит резкое увеличение твердости, почти на порядок. Подтверждено, что инертные наполнители снижают механическую прочность относительно начального диффузионно-твердеющего припоя, даже те, которые хорошо смачиваются галлием, однако существует некий диапазон, содержащий определенное количество инертного компонента, у порошка молибдена это 15 %, при котором микротвердость композиционного припоя выходит на максимум. The article discusses the possibility of regulating the properties of a diffusion-hardening solder based on a low-melting gallium-tin alloy and a solid component consisting of a copper-tin alloy powder by introducing an inert metal molybdenum powder and heat treatment. The microhardness and thermal stability of composite diffusion-hardening solders were evaluated. It is shown that repeated heat treatment at high temperatures contributes to the transition of the solder to an equilibrium state, with a sharp increase in hardness, almost by an order of magnitude. It is confirmed that inert fillers reduce the mechanical strength relative to the initial diffusion-hardening solder, even those that are well wetted with gallium, but there is a certain range containing a certain amount of the inert component, for molybdenum powder it is 15 %, at which the microhardness of the composite solder reaches the maximum.

scholarly journals STUDY OF THE PROPERTIES OF DIFFUSION-HARDENING COMPOSITE SOLDERS MODIFIED WITH A Ti-Mo POWDER MIXTURE

2021 ◽  
pp. 392-399
Author(s):  
Владимир Михайлович Скачков ◽  
Лилия Александровна Пасечник ◽  
Ирина Сергеевна Медянкина ◽  
Наиль Аделевич Сабирзянов
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Equilibrium State ◽  
Powder Mixture ◽  
Alloy Powder ◽  
Sharp Increase ◽  
Metallic Titanium ◽  
Zinc Alloys ◽  
X Ray ◽  
Thermal Stability Of

В статье обсуждается возможность регулирования свойств диффузионнотвердеющего припоя на основе легкоплавких сплавов галлий-олово, галлий-индийолово, галлий-олово-цинк и твердой компоненты состоящей из порошка сплава медь-олово посредством введения смеси инертных порошков металлического титана и молибдена после термической обработки при различных температурах. Оценена микротвердость и термическая устойчивость композиционных диффузионнотвердеющих припоев. Показано, что термическая обработка при более высоких температурах способствует переходу припоя в равновесное состояние, при этом происходит резкое увеличение твердости. Методом рентгенофазового анализа определены образующиеся в результате диффузионного твердения фазы. Показано, что при различных температурах обработки образуются разные фазы - наноразмерные интерметаллические соединения. За счет небольших добавок наполнителей, инертных или слабовзаимодействующих с галлием, но хорошо им смачиваемых, характеристики диффузионно-твердеющего припоя значительно улучшаются. The article discusses the possibility of regulating the properties of diffusion-hardening solder based on low-melted gallium-tin, gallium-indium-tin, gallium-tin-zinc alloys and a solid component consisting of a copper-tin alloy powder by introducing a mixture of inert powders of metallic titanium and molybdenum after the heat treatment at various temperatures. The microhardness and thermal stability of composite diffusion-hardening solders are evaluated. It is shown that the heat treatment at higher temperatures contributes to the transition of the solder to an equilibrium state, while a sharp increase in hardness occurs. The phases formed as a result of diffusion hardening were determined by the method of X-ray phase analysis. It is shown that at different processing temperatures, different phases are formed - nanoscale intermetallic compounds. Due to small additives of fillers that are inert or weakly interacting with gallium, but are well wetted by it, the characteristics of the diffusion-hardening solder are significantly improved.

scholarly journals New Method of Fabrication of Fe80Cr20 Alloy: Effect of its Technique on Crystallite Size and Thermal Stability

2020 ◽  
Vol 1 (1) ◽  
pp. 26-31
Author(s):  
Dafit Feriyanto ◽  
Supaat Zakaria
Keyword(s):  
Thermal Stability ◽  
Mechanical Alloying ◽  
Crystallite Size ◽  
Combination Treatment ◽  
Alloy Powder ◽  
Xrd Analysis ◽  
New Method ◽  
Ultrasonic Technique ◽  
Mechanically Alloyed ◽  
Thermal Stability Of

This paper focuses on the effect of the new method on the crystallite size and thermal stability of Fe80Cr20 alloy powder. Generally, the ball milling sample and ultrasonic technique sample have dissatisfaction result when applied at high temperature. In addition, the combination of both techniques not yet carried out. Therefore, this study aim to investigate an appropriate technique to produce smallest crystallite size in order to improve the thermal stability. The new method of mechanical alloying (mill) and ultrasonic technique (UT) were applied in order to reduce the crystallite size and improve thermal stability. The new method is called as combination treatment. This condition allows the enhancement of thermal stability of Fe80Cr20 alloy powder. In this study, mechanical alloying process was carried out by milling time of 60 hours. Then, the ultrasonic technique was performed at frequency of 35 kHz at 3, 3.5, 4, 4.5, and 5 hours. From XRD analysis, it was found that the broader peaks indicated the smaller crystallite size. It shows that the combination treatment (milled and UT) reduce the crystallite size up to 2.171 nm when mechanically alloyed for 60 hours (milled 60 h) and followed by ultrasonic treatment for 4.5 hours (UT 4.5 h). Smallest crystallite size enhance the thermal stability up to 12.7 mg which shown by TGA analysis during 1100 0C temperature operation. The combination treatment is method which is effective to fabricate Fe80Cr20 alloy powder.

Thermal Stability of Nanocrystallized Surface Layer in Al-Zn-Mg Alloy by Surface Mechanical Attrition Treatment

2007 ◽  
Vol 546-549 ◽  
pp. 1129-1134 ◽  
Author(s):  
Jin Fang Ma ◽  
Lan Qing Hu ◽  
Xu Guang Liu ◽  
Bing She Xu
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Surface Layer ◽  
Boundary Migration ◽  
Mg Alloy ◽  
Surface Mechanical Attrition Treatment ◽  
Mechanical Attrition ◽  
Nanostructured Layer ◽  
Average Grain Size ◽  
Thermal Stability Of

After surface mechanical attrition treatment (SMAT) for Al-Zn-Mg alloy, a gradient structure with average grain size increased from 20nm in surface layer to about 100nm at a depth of 20μm was formed. The thermal stability of surface nanostructured layer in Al-Zn-Mg alloy samples was investigated by vacuum annealing at 100°C, 150°C, 200°C and 250°C for 1h, respectively. The microstructural evolution as well as the microhardness along the depth from top surface layer to matrix of SMATed samples was analyzed. Experimental results showed that the grain size of surface nanocrystallites remains in submicro-scale, ranging from 300nm to 400nm, when annealed at a temperature of 250°C, and the microhardness of surface nanostructured layer was still high compared with that of matrix, indicating satisfying thermal stability of nanocrystallized layer. This might be attributed to the presence of substantive trident grain boundaries and pinning effect of dispersive precipitated phases in nanocrystalline materials, which hindered the grain boundary migration that leading to grain growth.

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