Effect of B Refinement on Structure and Fracture Morphology of Al-7 wt.% Si Alloy

2014 ◽  
Vol 590 ◽  
pp. 181-186
Author(s):  
Xiao Song Li ◽  
An Hui Cai ◽  
Ji Jie Zeng

Using optical microscope, electronic tensile testing machine, scanning electron microscopy methods, such as detailed treatment of the B hypoeutectic Al-Si alloy microstructure, mechanical properties and fracture morphology were studied. The results showed that after treatment by the B refinement, α-Al dendrite phase was refined, resulting in mechanical properties of Al-Si alloy significantly improved. Which, B content 0.036wt.%, the alloy the best, the σb, δ, respectively, than the non-thinning increased 67.8% and 15.2%. From the fracture surface, the fracture morphology of the specimen showed a quasi-cleavage fracture. Which, B content 0.036wt.% at the time of fracture is more deep dimples, and a good plastic toughness.

2017 ◽  
Vol 380 ◽  
pp. 198-211 ◽  
Author(s):  
A. Al Sumait ◽  
C. Delgado ◽  
F. Aldhabib ◽  
X. Sun ◽  
F. Alzubi ◽  
...  

The objective of the study was to optimize the strength and ductility values of the 4330M steel. Optimization was conducted through different types of heat treatments. Tensile testing, hardness testing, optical microscopy, and Scanning Electron Microscopy (SEM) were used to evaluate the mechanical properties and microstructure of the as-received and the heat treated samples. The alloy was provided from two vendors; vendor H and vendor S. Results showed that by increasing the tempering temperatures, strength values decreases, while ductility values remain unchanged. Vendor H samples had higher strength values and much finer grain structure which was revealed only at 5000x magnification.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 568
Author(s):  
Xinwei She ◽  
Xianquan Jiang ◽  
Bao Qi ◽  
Kang Chen

The effect of Er on microstructure and mechanical properties of the 5052 aluminum alloy with a big width-to-thickness ratio was investigated by a metallurgical microscope, scanning electron microscope and tensile testing machine. The results showed that the precipitates were slightly refined after Er addition and Al3Fe was transformed into Al6Fe and AlEr with/without a small amount of Fe or Si. The effect of Er on grain refinement was related to its content. When Er content was lower or higher than 0.4%, the grain would coarsen. Homogenization could refine the grain by controlling Er content and distribution in the Al matrix. Long time homogenization at high temperature would significantly reduce the strength of the 5052 aluminum alloy and 5052 aluminum alloys with low Er content, but help to improve the plasticity of those with high Er content. The ultimate tensile strength, yield strength and elongation of the as-cast 5052 aluminum alloy were 197 MPa, 117 MPa and 22.5% respectively. The strength was the highest, when Er content was 0.4 wt. % and the elongation was the best at 0.1 wt. % Er content.


2018 ◽  
Vol 202 ◽  
pp. 01001
Author(s):  
R. Ahmad ◽  
A.M.M. Elaswad ◽  
M. Z. Hamzah ◽  
N. R. Shahizan

The thermal parameters of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr cast alloy with 0.25 wt.% of erbium (Er) were evaluated by the computer-aided cooling curve thermal analysis(CA CCTA), whereas the microstructure analysis was investigated by the optical microscope and scanning electron microscopy. Results from the cooling curve and microstructure analysis showed that Er altered the grain size of the alloys. In addition, the grain size was reduced by approximately 19.6% with the addition of Er. Scanning electron microscopy results showed that Er formed an Mg-Zn-Nd-Er phase which distributed along the grain boundaries. Furthermore, the mechanical properties were investigated by hardness and tensile tests with Er addition. The addition of 0.25 wt.% of Er significantly improved the ultimate tensile strength and yield strength. In addition, the hardness value of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr increased by 13.9% with Er addition.


2007 ◽  
Vol 334-335 ◽  
pp. 749-752 ◽  
Author(s):  
Subrata Ghose ◽  
K.A. Watson ◽  
D.M. Delozier ◽  
D.C. Working ◽  
John W. Connell ◽  
...  

In efforts to improve the thermal conductivity (TC) of Ultem™ 1000, it was compounded with three carbon based nano-fillers. Multiwalled carbon nanotubes (MWCNT), vapor grown carbon nanofibers (CNF) and expanded graphite (EG) were investigated. Ribbons were extruded to form samples in which the nano-fillers were aligned. Samples were fabricated by compression molding where the nano-fillers were randomly oriented. The thermal properties were evaluated by DSC and TGA, and the mechanical properties of the aligned samples were determined by tensile testing. The degree of dispersion and alignment of the nanoparticles were investigated with high-resolution scanning electron microscopy. The thermal conductivity was measured in two directions using the Nanoflash technique.


2013 ◽  
Vol 834-836 ◽  
pp. 360-363
Author(s):  
X.Z. Wu ◽  
D.H. Xiao ◽  
Z.M. Zhu ◽  
X.X. Li ◽  
K.H. Chen

Effects of minor silver addition on microstructure, mechanical properties and corrosion resistances of Al-8Zn-1.Cu-1.3Mg-0.1Zr alloys were investigated using optical microscope (OM), scanning electron microscopy (SEM), mechanical properties and corrosion testing. The results show that minor silver addition decreases the recrystallization and corrosion resistance of the t77-tempered alloys.Tensile strength of the based alloy was increased by the 0.1 wt% silver addition.


2012 ◽  
Vol 503-504 ◽  
pp. 441-445 ◽  
Author(s):  
Lan Zhan ◽  
Chun Yuan Shi

The tensile and the fatigue tests of three different rolling states of SUS301L stainless steel welded joints were investigated, and their S-N curves were obtained and analyzed. The typical fracture morphology of fatigue specimens were observed by scanning electron microscopy (SEM). The results indicate that the tensile strength and the yield strength of three kinds of SUS301L stainless steel welded joints increase with increasing of rolling degrees, while only the elongation rate decreases with the increasing of rolling degrees; the median fatigue limit of SUS301L-DLT、SUS301L-ST、SUS301L-MT for fatigue life 2×106 cycles are 247.5MPa, 331MPa, 266.7MPa.


2013 ◽  
Vol 423-426 ◽  
pp. 771-774
Author(s):  
Ning Ma ◽  
Huan Tao Wu ◽  
Fu Xing Ye ◽  
Guo Sheng Zhang

In this work, a scrapped cross shaft which was assembled at the differential of ZL50C loader was analyzed by scanning electron microscopy (SEM) to examine the failure mechanism and was remanufactured by HVOF with ~500μm thickness WC-12Co coatings on it. The microstructure, phase compositions and properties of deposited WC-12Co coatings were investigated through optical microscope (OM), SEM, X-ray diffraction (XRD), microhardness tester and tensile testing machine. The results show that the coatings were very dense, and their porosities were lower than 1%. According to the X-ray Diffraction (XRD) analysis, the phase compositions of the sprayed coatings consisted of WC, Co and W2C. The microhardness of the coating was approximated to 1100 HV0.1and the bonding strength was higher than 63.7 MPa. It can be concluded that WC-12Co coating sprayed by HVOF was suitable for the remanufacturing of shaft parts.


2013 ◽  
Vol 662 ◽  
pp. 356-361
Author(s):  
Xing Hai Liu ◽  
Feng Juan Wu ◽  
Hui Bin Wu ◽  
Ji Quan Sun ◽  
Xue Ping Ren

Heat treatment has a signifieant impact on the performance of the GCr15 die steel. Using scanning electron microscopy, optical microscopy, hardness tester and tensile testing machine analyses the influence of double-fined treatment on microstructure and mechanical properties of GCr15 steels. The results show that the double-fined treatment can make the carbids which haven’t insoluted fine to 320nm and the grains fine to No. 10. The dislocated martensite become more after double-fined treatment; at the same time, there are more sheet-retained austernite in lathy martensite and around sheet martensite; broken-orifice changes from definitely cleavage brittleness fracture to definitely cleavage tenacity fracture. By double-fined treatment, die steel can be given the neeessary strength and toughness, and the life can be substantially increased. The superplasticity of GCr15 die steel was improved by double-fined treatment. The optimal temperature range of the elongation is: 680~780°C. Anti-oxidants can improve the elongation of GCr15 steels.


2012 ◽  
Vol 510 ◽  
pp. 762-767 ◽  
Author(s):  
Zhao Zhe Zhang ◽  
Chen Chen ◽  
Long Hua Zhao

The melt grafting of maleic anhydride (MAH) onto poly (3-hydroxybutyrate-co-4-hydrox-ybutyrate)[P(3HB-co-4HB)]/polylactic acid (PLA) blends were carried out via reactive extrusion. The effects of the contents of MAH, initiator (BPO) on the graft ratio were studied. The effects of grafting modification on thermal properties, mechanical properties, fracture morphology and compatibility of P(3HB-co-4HB)/PLA blends were characterized by differential scanning calorimeter (DSC), electronic universal testing machine and scanning electron microscopy (SEM) etc. The results showed that the graft ratio of blends increased to a maximum and then decreased with increasing contents of MAH and BPO; The tensile strength, impact strength of blends were significantly improved, and the graft ratio achieved the maximum value at 1.0phr MAH and 0.3phr BPO; Through analysis from DSC and SEM, it indicated that the compatibility of P(3HB-co-4HB)/PLA blends was improved effectively.


Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.


Sign in / Sign up

Export Citation Format

Share Document