Influence of Si Content on Microstructure and Erosion Properties of Al-Based Alloy

2014 ◽  
Vol 960-961 ◽  
pp. 109-112
Author(s):  
Xiao Ming Wang ◽  
Sheng Zhu ◽  
Jian Zhong Cui ◽  
Qing Chang ◽  
Qing Feng Zhu
Keyword(s):  
Magnesium Alloy ◽  
Chemical Elements ◽  
Eutectic Silicon ◽  
Testing Machine ◽  
Theoretical Principle ◽  
Primary Crystal ◽  
Silicon Phase ◽  
Crystal Silicon ◽  
Erosion Properties ◽  
Si Content

In order to develop new protective materials for magnesium alloy, Al-based alloys with different Si-content were fabricated by copper mold casting. Microstructure, erosion properties of the ingot samples were characterized or tested by using spectrum analysis, optical imcroscope, salt testing machine etc, respectively. The results indicated that the microstructure of Al-1.9Si-1.32Mg-0.40Mn was mostly dendritic crystal. That of Al-13Si consisted of α-Al, flaky eutectic silicon and primary crystal silicon. That of Al-18Si-0.01%P was consistent of a large proporation of primary crystal silicon phase, a part of eutectic silicon phase and a little of α-Al phase. With Si-content increasing, anti-corrosion properties of Al-based alloy gradually improved, which could provide theoretical principle to determine chemical elements of protective materials for magnesium alloy.

Effect on P-Element Modification on Microstructure of Al-Based Alloy

2014 ◽  
Vol 556-562 ◽  
pp. 620-623
Author(s):  
Xiao Ming Wang ◽  
Sheng Zhu ◽  
Jian Zhong Cui ◽  
Qing Chang ◽  
Qing Feng Zhu
Keyword(s):  
Magnesium Alloy ◽  
Optical Microscopy ◽  
P Element ◽  
Primary Crystal ◽  
Casting Method ◽  
Silicon Phase ◽  
Crystal Silicon ◽  
High Silica ◽  
Dc Casting ◽  
Processing Control

To develop high wear-resistant protective materials for magnesium alloy, high-silica Al-based alloy modified via P-element was fabricated by DC casting method. Microstructure of ingot samples was observed by using optical microscopy (OM), etc. The results demonstrated that Al-Si-0.01%P alloy with unique microstructure and without defects such as voids and rarefaction might be generated by processing control. Owing to modification by Al-P interalloy, primary crystal silicon phase in hypereutectic Al-Si alloy were refined effectively. Its size in Al-18Si-0.01%P alloy decreased from 50μm to 20μm, and distributed uniquely than that in Al-18Si alloy. Al-P acted as heterogeneous core of primary crystal silicon phase, which was the main mechanism for Al-P interalloy to modify primary crystal silicon in Al-Si alloy.

Influences of Complex Modification of RE and P on the Wear Resistance of Hypereutectic Al-24Si Alloy

2011 ◽  
Vol 284-286 ◽  
pp. 1647-1650
Author(s):  
Niu Can Liu ◽  
Jun Qing Li ◽  
Hai Dong Li
Keyword(s):  
Weight Loss ◽  
Wear Resistance ◽  
Wear Mechanism ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Primary Crystal ◽  
Crystal Silicon ◽  
Unmodified Alloy ◽  
Improve Wear Resistance ◽  
Silicon Particles

The influences of RE and P complex modifications on microstructures and wear-resistance of hypereutectic Al-24Si alloy were studied. The results show that the complex modifications of P and RE make the coarse block primary crystal silicon refined and their edges and angles are passivated, the large needle-like network eutectic silicon be modified to the fine lamella or particle ones. The optimum modification effect occurs with 0.10%P and 0.9%RE. The complex modification of P and RE can also obviously improve wear resistance of hypereutectic Al-24Si alloy. When the tested alloys modified with 0.10%P and 0.9%RE, the optimal wear resistance of modified alloys is obtained. The weight loss is decreased to 3.9mg from 5.4mg of the unmodified alloy, decreased by 27.8%. The abrasive wear caused by the breaking of Si phase is dominant wear mechanism of the alloy. It can be attributed to the refinement of primary silicon and eutectic silicon particles and the increase of strength and ductibility of alloys caused by the complex modification of P and RE.

Effect of Si Content on Microstructure and Properties of 60Si2CrVA Spring Steel

2014 ◽  
Vol 968 ◽  
pp. 63-66 ◽  
Author(s):  
Fei Zhao ◽  
Zhan Ling Zhang ◽  
Jun Shuai Li ◽  
Cui Ye ◽  
Ni Li
Keyword(s):  
Mechanical Properties ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Testing Machine ◽  
Spring Steel ◽  
Impact Testing ◽  
X Ray ◽  
Comprehensive Properties ◽  
Spring Steels ◽  
Si Content

The microstructure and mechanical properties of the four spring steels with different Si content treated by Q-I-Q-T process were studied by metallographic microscope, MTS, impact testing machine and X-ray stress analyzer. The results show that the tensile strength and yield strength is first increased and then decreased with the increase of Si content, the volume fraction of retained austenite and elongation are fist decreased and then increased when the Si content is less than 2.1%, and the microstructure become finer and homogeneous. When Si content reaches 2.1%, the comprehensive properties of 60Si2CrVA spring steel is the best.

Mechanical Properties Comparison of Different La Content in AZ91

2014 ◽  
Vol 620 ◽  
pp. 67-72 ◽  
Author(s):  
Yan Yan Zhang ◽  
Chun Xia He ◽  
Hang Song Yang ◽  
Jian Xiu Liu
Keyword(s):  
Magnesium Alloy ◽  
Mechanical Performance ◽  
Testing Machine ◽  
Powder Metallurgy Method ◽  
Az91 Magnesium Alloy ◽  
Compression Performance ◽  
Hardness Tester ◽  
Mechanics Performance ◽  
Tension And Compression ◽  
Az91 Magnesium

In order to improve the comprehensive mechanics performance of AZ91 magnesium alloy which is used as car's material, the La element was added in AZ91 magnesium alloy and specimens was prepared by powder metallurgy method. The influence of La on microstructure, hardness and compression performance of AZ91 a magnesium alloy specimen was studied using metallographic electronic microscope, hardness tester, universal tension and compression testing machine. The experimental results show that when amount of La's addition is 1.2%, its mechanical performance is best, hardness is 67.1 HV, compressive strength is 115.8 MPa, increased respectively by 20.0% and 29.5% compared the AZ91 magnesium alloy substrate, and the grain refinement effect of AZ91 magnesium alloy is the best at this time.

Study on the Modification Effect of Al-Sr Master Alloy on A356 Aluminum Alloy

2020 ◽  
Vol 998 ◽  
pp. 3-8
Author(s):  
Gui Qing Chen ◽  
Gao Sheng Fu ◽  
Kai Huai Yang ◽  
Chao Sheng Lin
Keyword(s):  
Aluminum Alloy ◽  
Master Alloy ◽  
Eutectic Silicon ◽  
A356 Alloy ◽  
Short Fiber ◽  
Tensile Fracture ◽  
A356 Aluminum Alloy ◽  
Silicon Phase ◽  
A356 Aluminum ◽  
Modification Treatment

A356 aluminum alloy was modified by Al-Sr master alloy, and the eutectic silicon phase was changed from long needle to short fiber. Compared with the untreated, the secondary dendrite spacing decreased by 14.37 %, the tensile strength increased by 13.0 MPa, and the elongation increased by 29.51 %. After modification treatment, more developed secondary dendrites and block inclusions can be seen in the tensile fracture of A356 alloy, which is not conducive to the plasticity and fatigue resistance of the alloy.

The Production and Properties of Electrolytic Zn-Ni Layers Deposited by Pulse Current Method

2010 ◽  
Vol 636-637 ◽  
pp. 1047-1052
Author(s):  
Katarzyna Wykpis ◽  
Antoni Budniok
Keyword(s):  
Corrosion Resistance ◽  
Chemical Composition ◽  
Pulse Current ◽  
Chemical Elements ◽  
Testing Machine ◽  
Intermetallic Phase ◽  
Current Method ◽  
Surface Chemical ◽  
Surface Chemical Composition ◽  
Current Densities

The Zn-Ni layers were obtained by electrolytic method in the conditions of pulse current with symmetric current pause. The austenitic steel (OH18N9) was used as the cathode. The morphology, phase and surface chemical composition of the layers deposited at reduction current densities ic = 5 – 25 mAcm2, were defined. The surface morphology of deposited layers and surface chemical elements distribution were studied using a scanning electron microscope (JEOL JSM-6480). On the basis on this research, the possibility of deposition of Zn-Ni layers contained about 8 – 10 % at. Ni was exhibited. The optimal pulse current condition of Zn-Ni layers deposition were proposed namely ic=20mA•cm2, ton = toff = 2ms. It was stated, that surface chemical composition of Zn-Ni layers is independent on pulse current densities of deposition, whereas development of Zn-Ni surface increases with the increase in the pulse current density of deposition. The corrosion resistance investigations showed that passivation and heat treatment improved the corrosion resistance of Zn-Ni layers in 5% NaCl solution. Higher corrosion resistance of heated Zn-Ni layers is caused by the creation of Ni5Zn21 intermetallic phase. Moreover the heated Zn-Ni layers are characterized by slightly higher corrosion resistance compared with metallic Cd. Microhardness of the layers was investigated by Vickers diamond testing machine.

Research on the Technology for DC CMT Welding of AZ31B Magnesium Alloy

2013 ◽  
Vol 483 ◽  
pp. 18-22
Author(s):  
Rui Ying Zhang ◽  
Yun Yan Hu ◽  
Jun Wang
Keyword(s):  
Magnesium Alloy ◽  
Welding Speed ◽  
Orthogonal Experiment ◽  
Testing Machine ◽  
Weld Zone ◽  
Welding Current ◽  
Alloy Sheet ◽  
Arc Length ◽  
Az31b Magnesium Alloy ◽  
Cmt Welding

Orthogonal experiment method was used on DC CMT welding of AZ31B magnesium alloy sheet. The tensile test was carried out on the CMT5305 microcomputer control universal testing machine .The effect regular of welding current, arc length correction and welding speed on tensile strength and elongation was analyzed and acquired the optimal combination of process parameters. That is, welding current is 62A, arc length correction is +30% and welding speed is 50cm/min. The microhardness test on joints was carried out. Its found that the curve of microhardness is "W" shaped and the micro-hardness of HAZ is minimum and that of weld zone is maximum.

Friction and Wear Properties of Al-Based Hypereutectic Silicon Coatings Fabricated by Supersonic Particles Deposition on ZM5 Magnesium Alloy

2014 ◽  
Vol 952 ◽  
pp. 125-129
Author(s):  
Xiao Jun Shi ◽  
Hai Bo Jiang ◽  
Ju Kun Yao ◽  
Zhi Qian Wang ◽  
Chao Ji Zhou ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Testing Machine ◽  
Three Dimensional ◽  
Micro Hardness ◽  
Wear Properties ◽  
Hardness Tester ◽  
Wear Protection ◽  
Resistant Layer ◽  
Mechanical Bonding ◽  
Abrasion Testing

To improve the anti-wear properties of Mg alloys, Al-13Si, Al-15Si and Al-19Si coatings were prepared by supersonic particles deposition on the surface of ZM5 magnesium alloy. Micro-structure and anti-wear properties of the coatings were examined by digital micro-hardness tester, XRD, friction and abrasion testing machine, three-dimensional microscope and SEM. The results show that the wear-resistant layer and the magnesium substrate can be well integrated as mechanical bonding and the main wear failure mechanism of the three coatings is adhesive wear. Moreover, the micro-hardness of Al-19Si coating is 141.47HV0.05, much higher than Al-13Si coating (134.97HV0.05) and Al-15Si coating (136.02HV0.05). Besides, the anti-wear properties of Al-19Si coating is optimal, superior to Al-15Si coating and Al-13Si coating. All of those indicate that Al-19Si coating can provide the most excellent anti-wear protection for ZM5 magnesium alloy.

Fracture Toughness Measurement of a Micro-Sized Single Crystal Silicon

2005 ◽  
Vol 297-300 ◽  
pp. 292-298 ◽  
Author(s):  
Satoru Koyama ◽  
Kazuki Takashima ◽  
Yakichi Higo
Keyword(s):  
Fracture Toughness ◽  
Single Crystal ◽  
Ion Beam ◽  
Testing Machine ◽  
Single Crystal Silicon ◽  
Mems Devices ◽  
Type Specimens ◽  
Crystal Silicon ◽  
Fracture Toughness Measurement ◽  
Toughness Measurement

Reliability is one of the most critical issues for designing practical MEMS devices. In particular, the fracture toughness of micro-sized MEMS elements is important, as micro/nano-sized flaws can act as a crack initiation sites to cause failure of such devices. Existing MEMS devices commonly use single crystal silicon. Fracture toughness testing upon micro-sized single crystal silicon was therefore carried out to examine whether a fracture toughness measurement technique, based upon the ASTM standard, is applicable to 1/1000th sized silicon specimens. Notched cantilever beam type specimens were prepared by focused ion beam machining. Two specimens types with different notch orientations were prepared. The notch plane/direction were (100)/[010], and (110)/[ ＿ ,110], respectively. Fracture toughness tests were carried out using a mechanical testing machine for micro-sized specimens. Fracture has been seen to occur in a brittle manner in both orientations. The provisional fracture toughness values (KQ) are 1.05MPam1/2 and 0.96MPam1/2, respectively. These values meet the micro-yielding criteria for plane strain fracture toughness values (KIC). Fracture toughness values for the orientations tested are of the same order as values in the literature. The results obtained in this investigation indicate that the fracture toughness measurement method used is applicable for micro-sized components of single crystal silicon in MEMS devices.

Effect of LaCl3 on the Structure and Properties of Magnesium Alloys

2005 ◽  
Vol 488-489 ◽  
pp. 111-114 ◽  
Author(s):  
Guo Hua Wu ◽  
Hong Tao Guo ◽  
Xiao Qing Zeng ◽  
Wen Jiang Ding
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Testing Machine ◽  
Mg Alloy ◽  
Image Analyzer ◽  
Universal Material Testing Machine ◽  
Alloy Properties ◽  
Re Elements ◽  
Mg Melt

By use of the Zwick electronic universal material testing machine, X-ray diffractometer, SEM, EDX, image analyzer and corrosion test, the effects of LaCl3 on the mechanical properties, structure, fractography and corrosion behavior of magnesium alloy have been studied. The results show that minute nodular Al10La2Mn7 phases can be formed in Mg melts after fluxes containing LaCl3 are added to Mg melt. The Al10La2Mn7 phases can act as the nucleating site of γ phases, and the γ phases can be refined. With the flux containing 5% LaCl3, the σb and δ of the Mg alloy can be improved from 161MPa and 2.1% to 203MPa and 4.0% by 26% and 100%, respectively. The corrosion rate of magnesium alloys can decrease from 1.10 mg/(cm2.d) to 0.17 mg/(cm2.d) by 84% with the use of flux containing 5% LaCl3. Rare earth (RE) elements are often added to the magnesium alloy to improve the alloy structure and the room or elevated temperature mechanical properties. But up to present, the RE elements added to Mg melt is often in the form of pure RE alloy or RE master alloy [1]. Because RE is the oxidizable material, this kind of adding process often leads to low RE utilization ratio and high use-cost. Besides, this process can easily induce segregation of RE and the appeared coarse RE phases will lower the Mg alloy mechanical properties. By far, there is few research reports about RE contained compound added to Mg alloy melt. In this paper, the effects of Lanthanum chloride (LaCl3) on the structure and mechanical properties of Mg alloy are studied for the first time. The aim is to explore a new way to improve the Mg alloy properties.

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