Influence of Annealing on Microstructure and Mechanical Properties of Isotactic Polypropylene with β-Phase Nucleating Agent

2009 ◽  
Vol 42 (17) ◽  
pp. 6647-6655 ◽  
Author(s):  
Hongwei Bai ◽  
Yong Wang ◽  
Zhijie Zhang ◽  
Liang Han ◽  
Yanli Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Isotactic Polypropylene ◽  
Nucleating Agent ◽  
Β Phase ◽  
Microstructure And Mechanical Properties

Unusual Tuning of Mechanical Properties of Isotactic Polypropylene Using Counteraction of Shear Flow and β-Nucleating Agent on β-Form Nucleation

2009 ◽  
Vol 42 (12) ◽  
pp. 4343-4348 ◽  
Author(s):  
Yan-Hui Chen ◽  
Gan-Ji Zhong ◽  
Yan Wang ◽  
Zhong-Ming Li ◽  
Liangbin Li
Keyword(s):  
Mechanical Properties ◽  
Shear Flow ◽  
Isotactic Polypropylene ◽  
Nucleating Agent

scholarly journals Tailoring Microstructure and Mechanical Properties of Additively-Manufactured Ti6Al4V Using Post Processing

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 658
Author(s):  
Yaron Itay Ganor ◽  
Eitan Tiferet ◽  
Sven C. Vogel ◽  
Donald W. Brown ◽  
Michael Chonin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Fatigue Resistance ◽  
Electron Beam Melting ◽  
High Reliability ◽  
National Laboratory ◽  
Post Processing ◽  
Proof Stress ◽  
Β Phase ◽  
Microstructure And Mechanical Properties

Additively-manufactured Ti-6Al-4V (Ti64) exhibits high strength but in some cases inferior elongation to those of conventionally manufactured materials. Post-processing of additively manufactured Ti64 components is investigated to modify the mechanical properties for specific applications while still utilizing the benefits of the additive manufacturing process. The mechanical properties and fatigue resistance of Ti64 samples made by electron beam melting were tested in the as-built state. Several heat treatments (up to 1000 °C) were performed to study their effect on the microstructure and mechanical properties. Phase content during heating was tested with high reliability by neutron diffraction at Los Alamos National Laboratory. Two different hot isostatic pressings (HIP) cycles were tested, one at low temperature (780 °C), the other is at the standard temperature (920 °C). The results show that lowering the HIP holding temperature retains the fine microstructure (~1% β phase) and the 0.2% proof stress of the as-built samples (1038 MPa), but gives rise to higher elongation (~14%) and better fatigue life. The material subjected to a higher HIP temperature had a coarser microstructure, more residual β phase (~2% difference), displayed slightly lower Vickers hardness (~15 HV10N), 0.2% proof stress (~60 MPa) and ultimate stresses (~40 MPa) than the material HIP’ed at 780 °C, but had superior elongation (~6%) and fatigue resistance. Heat treatment at 1000 °C entirely altered the microstructure (~7% β phase), yield elongation of 13.7% but decrease the 0.2% proof-stress to 927 MPa. The results of the HIP at 780 °C imply it would be beneficial to lower the standard ASTM HIP temperature for Ti6Al4V additively manufactured by electron beam melting.

scholarly journals Evolution in Microstructure and Mechanical Properties of Inconel 783 Alloy Bolts after Long Term High-Temperature Aging at 700 °C

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1440 ◽  
Author(s):  
Peng Duan ◽  
Zongde Liu ◽  
Shuchao Gu ◽  
Song Wang
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Aging Time ◽  
Aging Temperature ◽  
Testing Machine ◽  
Impact Testing ◽  
Rapid Decline ◽  
Β Phase ◽  
Microstructure And Mechanical Properties ◽  
Orientation Distributions

This paper described systematically the changes in microstructure and mechanical properties of Inconel 783 alloy after a considerably long time (equivalently 55,000 h, about 76.4 months) of thermal exposure. Based on the Inconel 783 alloy bolts of an intermediate pressure main stop valve used in a 1000 MW ultra-supercritical unit, the evolution of microstructures and mechanical properties were studied after 700 °C aging temperature with different aging times (1000 h, 3000 h and 20,000 h, corresponding to about 1.4 months, 4.2 months and 27.8 months, respectively), using an optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffractometer (XRD), a universal tensile testing machine and impact testing machine. The results indicated that the bolts aged for 1000 h in two temperatures, showing the second needle β phase, of which the quantity and size obviously increased with aging time. Meanwhile, the characteristics in quantity and shape of the primary β phase changed obviously with the aging time, which transformed to strip the Ni5Al3 and Laves-Nb-rich brittle phase in the matrix after aging for 20,000 h. The size of the γ’ phase grew bigger with aging time, and orientation distributions have been observed obviously at 3000 h aging in 700 °C. Compared with the 650 °C aging temperature, the coarsening of γ’ precipitates and second needle β, the orientation distributions of γ’ were more obvious at the 700 °C aging temperature with aging time, which resulted in the rapid decline in yield strength and tensile strength and obvious increase in the brittleness for Inconel 783 alloy bolts.

Effect of AlN on Microstructure and Mechanical Properties of Mg-Al-Zn Alloy

2011 ◽  
Vol 704-705 ◽  
pp. 1095-1099
Author(s):  
Peng Liu ◽  
Hao Ran Geng ◽  
Zhen Qing Wang ◽  
Jian Rong Zhu ◽  
Fu Sen Pan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Tensile Testing ◽  
Cast Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Microstructure And Mechanical Properties ◽  
Zn Alloy

Effects of AlN addition on the microstructure and mechanical properties of as-cast Mg-Al-Zn magnesium alloy were investigated using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and tensile testing. Five different samples were made with different amounts of AlN(0wt%, 0.12wt%, 0.30wt%, 0.48wt%, 0. 60wt%). The results show that the phases of as-cast alloy are composed of α-Mg,β-Mg17Al12. The addition of AlN suppressed the precipitation of the β-phase. And, with the increase of AlN content, the microstructure of β-phase was changed from the reticulum to fine grains. When AlN content was up to 0.48wt% in the alloy, the β-phase became most uniform distribution. After adding 0.3wt% AlN to Al-Mg-Zn alloy, the average alloy grain size reduced from 102μm to 35μm ,the tensile strength of alloy was the highest. The average tensile strength increased from 139MPa to 169.91MPa, the hardness increased from 77.7HB to 98.4HB, but the elongation changes indistinctively. However, when more amount of AlN was added, the average alloy grain size did not reduce sequentially and increased to 50μm by adding 0.6wt% AlN and the β-phase became a little more. Keywords: Al-Mg-Zn alloy; AlN; β-Mg17Al12; Tensile strength

Improved ductility of aged Mg-9Al-1Zn alloy strip by electropulsing treatment

2009 ◽  
Vol 24 (5) ◽  
pp. 1810-1814 ◽  
Author(s):  
Yanbin Jiang ◽  
Guoyi Tang ◽  
Chanhung Shek ◽  
Yaohua Zhu ◽  
Lei Guan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Atomic Diffusion ◽  
Alloy Strip ◽  
Β Phase ◽  
Microstructure And Mechanical Properties ◽  
Elongation To Failure ◽  
Electropulsing Treatment

The effect of electropulsing treatment (EPT) on the microstructure and mechanical properties of aged Mg-9Al-1Zn alloy strip was studied. EPT was found to accelerate tremendously the β phase spheroidization in the aged Mg-9Al-1Zn alloy. This improved microstructure exhibits excellent mechanical properties, that is, increasing elongation to failure significantly without loss of tensile strength. The spheroidization of the β phase during EPT was attributed to the reduction of the nucleation thermodynamic barrier and enhancement of atomic diffusion.

Effect of Heat Treatment on Microstructure and Mechanical Properties of MA2-1 Alloy Sheet

2005 ◽  
Vol 488-489 ◽  
pp. 151-154
Author(s):  
Weichao Zheng ◽  
Xiao Li Sun ◽  
Peijie Li ◽  
Daben Zeng ◽  
L.B. Ber
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
High Purity ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Alloy Sheet ◽  
Β Phase ◽  
Microstructure And Mechanical Properties ◽  
Mg17al12 Phase

Effect of heat treatment on the microstructure and mechanical properties of high purity MA2-1(Mg-5wt.%Al-1wt.%Zn-0.4wt.%Mn) alloy sheet were investigated. X-ray diffraction analysis indicated that the microstructure of high purity MA2-1 alloy sheet annealed consisted of α-Mg solid solution, β (Mg17Al12) phase and Al-Mn phases such as Al6Mn and Al10Mn3. β phase dissolved into α-Mg solid solution during the solution treatment and formed supersaturated α-Mg solid solution. After aging at the temperatures of 423 K, 473 K and 523 K for 12 hours, β phase precipitated from the supersaturated α-Mg solid solution. Optical microscope observation found that the grain size of the MA2-1 alloy sheet became larger after heat treatment. As a result, the mechanical properties of the MA2-1 alloy sheet such as the tensile strength and yield strength declined after the heat treatment.

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