Influence of chemical composition on corrosion resistanceof AZ91D magnesium alloy ingots

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭａｇｎｅｓｉｕｍａｌｌｏｙｓｈａｖｅｆｏｕｎｄｍｏｒｅａｎｄｍｏｒｅｕｓ ｅｓｉｎｔｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎａｎｄｔｒａｎｓｐｏｒｔａｔｉｏｎｉｎｄｕｓｔｒｉｅｓｄｕｅｔｏｔｈｅｉｒｅｘｃｅｌｌｅｎｔｐｒｏｐｅｒｔｉｅｓｓｕｃｈａｓｈｉｇｈｓｔｒｅｎｇｔｈｔｏｗｅｉｇｈｔｒａｄｉｏ ,ｇｏｏｄｃｏｎｄｕｃｔｉｖｉｔｙ ,ａｐｐｒｏｐｒｉａｔｅｅｌｅｃ ｔｒｏ ｍａｇｎｅｔｉｃｓｈｉｅｌｄｉｎｇｐｒｏｐｅｒｔｙ .Ｈｏｗｅｖｅｒｔｈｅｉｒｃｏｒ ｒｏｓｉｏｎｂｅｈａｖｉ…     

Tensile and creep properties of Mg-9Al based alloys containing bismuth

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭａｇｎｅｓｉｕｍａｌｌｏｙｓａｒｅｂｅｉｎｇｉｎｃｒｅａｓｉｎｇｌｙｕｓｅｄｉｎａｕｔｏｍｏｂｉｌｅｉｎｄｕｓｔｒｙｉｎｏｒｄｅｒｔｏｄｅｃｒｅａｓｅｍａｓｓｔｈｅｒｅｂｙｒｅｄｕｃｉｎｇｆｕｅｌｃｏｎｓｕｍｐｔｉｏｎａｎｄｐｏｌｌｕｔｉｏｎ[1～ 4 ] .Ｈｏｗ ｅｖｅｒ,ｔｈｅｒｅｄｕｃｔｉｏｎｏｆｙｉｅｌｄｓｔｒｅｎｇｔｈａｎｄｃｒｅｅｐｒｅｓｉｓ ｔａｎｃｅｏｆＭｇ Ａｌａｌｌｏｙａｂｏｖｅ 12 0℃ｌｉｍｉｔｓｔｈｅｉｒａｐｐｌｉｃａ ｔｉｏｎｓｉｎａｕｔｏｍｏｂｉｌｅ…     

Microstructure and properties of AZ80 magnesium alloy prepared by hot extrusion from recycled machined chips

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭａｇｎｅｓｉｕｍａｌｌｏｙｓｈａｖｅｍａｎｙａｄｖａｎｔａｇｅｓｓｕｃｈａｓｌｏｗｄｅｎｓｉｔｙ ,ｈｉｇｈｓｐｅｃｉｆｉｃｓｔｒｅｎｇｔｈ ,ｇｏｏｄｅｌｅｃｔｒｏｍａｇ ｎｅｔｉｃｓｈｉｅｌｄｉｎｇｃｈａｒａｃｔｅｒｉｓｔｉｃｓ ,ｅｘｃｅｌｌｅｎｔｃａｓｔａｂｉｌｉｔｙａｎｄｍａｃｈｉｎａｂｉｌｉｔｙｅｔｃ .Ｍａｇｎｅｓｉｕｍｉｓａｎａｂｕｎｄａｎｔｅｌｅ ｍｅｎｔｓｉｎｃｅａｂｏｕｔ 1.93% (ｍａｓｓｆｒａｃｔｉｏｎ)ｏｆｅａｒｔｈｃｒｕｓｔｃｏｎｓｉｓｔｏｆｍａｇｎｅ…     

Fabrication and characteristics of magnesium alloys produced via powder metallurgy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭａｇｎｅｓｉｕｍａｌｌｏｙｓ ,ｅｓｐｅｃｉａｌｌｙＭｇｍａｔｒｉｘｃｏｍ ｐｏｓｉｔｅｓ ,ａｒｅｅｘｃｅｌｌｅｎｔｃａｎｄｉｄａｔｅｓｆｏｒｅｎｇｉｎｅｅｒｉｎｇｌｉｇｈｔｓｔｒｕｃｔｕｒａｌｍａｔｅｒｉａｌｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｈｉｇｈｓｐｅｃｉｆｉｃｓｔｉｆｆ ｎｅｓｓａｎｄｓｐｅｃｉｆｉｃｓｔｒｅｎｇｔｈ ,ｇｏｏｄｄｉｍｅｎｓｉｏｎａｌｓｔａｂｉｌｉｔｙａｎｄｈｉｇｈｄａｍｐｉｎｇｃａｐａｃｉｔｙ .Ｔｈｕｓ ,Ｍｇａｌｌｏｙｓａｒｅｅｘ ｐｅｃｔｅｄｉｎａｄ…     

Study on electrochemical surface modification of coal by FTIR and Raman spectra

1　ＩＮＴＲＯＤＵＣＴＩＯＮＨｉｇｈｓｕｌｆｕｒｃｏａｌｏｃｃｕｐｉｅｓａｌａｒｇｅ ｐａｒｔｏｆｔｈｅｗｈｏｌｅｄｅｐｏｓｉｔｏｆｃｏａｌｉｎｔｈｅＳｏｕｔｈ ＷｅｓｔａｎｄｔｈｅＥａｓｔｏｆＣｈｉｎａ .Ｗｉｔｈｏｕｔｗａｓｈｉｎｇａｎｄｄｅｓｕｌｆｕｒｉｚａｔｉｎｇ ,ｔｈｅｃｏｍｍｅｒｃｉａｌｃｏａｌｉｓｏｆｌｏｗｑｕａｌｉｔｙ ,ｌｏｗｃｏｍｂｕｓｔｉｏｎｅｆ ｆｉｃｉｅｎｃｙｗｉｔｈｌａｒｇｅｃｏａｌｗａｓｔｉｎｇ ,ｇａｓａｓｈ ,ＣＯ2 ａｎｄＮＯｘ .Ａｂｏｖｅａｌｌ,ｔｈｅｃｏｍｂｕｓｔｉｏｎ…     

Chaos dynamic characteristics during mine fires

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭｉｎｅｆｉｒｅｉｓｏｎｅｏｆｔｈｅｃｒｉｔｉｃａｌｄｉｓａｓｔｅｒｓｉｎｕｎｄｅｒ ｇｒｏｕｎｄｃｏａｌｍｉｎｉｎｇ[1] .Ｏｎｃｅｆｉｒｅａｃｃｉｄｅｎｔｓｈａｐｐｅｎ ,ｔｈｅｙｃａｕｓｅａｌａｒｇｅｌｏｓｓｏｆｌｉｖｅｒｓ ,ｄｅｓｔｒｏｙｇｅｎｅｒｏｕｓｃｏａｌｒｅｓｏｕｒｃｅｓａｎｄｅｑｕｉｐｍｅｎｔ.Ｉｆｔｈｅｙａｒｅｎｏｔｈａｎｄｌｅｄｐｒｏｐｅｒｌｙａｎｄｔｉｍｅｌｙ ,ｔｈｅｙｍａｙｂｅｉｎｄｕｃｅｍｏｒｅｓｅｒｉｏｕｓｃｏｎｓｅｑｕｅｎｃｅｓｓｕｃｈａｓｇａ…     

Degradation characteristics of Ti/(IrO2+Ta2O5) coating anodes in H2SO4 solution

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｉｂａｓｅｄＩｒＯ2 ｃｏａｔｉｎｇａｎｏｄｅｓｗｅｒｅｗｉｌｄｌｙｕｓｅｄｉｎｅｌｅｃｔｒｏｃｈｅｍｉｃａｌｉｎｄｕｓｔｒｙｆｏｒｔｈｅｉｒｈｉｇｈｅｌｅｃｔｒｏｃａｔａｌｙｔｉｃａｃｔｉｖｉｔｙａｎｄｓｔａｂｉｌｉｔｙ[1] .Ｉｎａｎｅｘｔｒｅｍｅｃｏｎｄｉｔｉｏｎ ,ｓｕｃｈａｓｈｉｇｈ ｓｐｅｅｄｅｌｅｃｔｒｏｄｅｐｏｓｉｔｉｏｎ ,ｈｏｗｅｖｅｒ ,ｔｈｅｓｔａｂｉｌｉｔｙｏｆＩｒＯ2 ｉｓｎｏｌｏｎｇｅｒｓａｔｉｓｆｉｅｄ .Ｔｈｅｒｅｆｏｒｅ ,ｔｈｅｍｏｄｉｆｉｃａｔ…     

Chemical stability of La_2O_3 in La_2O_3-Mo cathode materials

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈＯ2 Ｗｔｈｅｒｍｉｏｎｉｃｃａｔｈｏｄｅｓａｒｅｓｔｉｌｌｗｉｄｅｌｙｕｓｅｄｉｎｈｉｇｈ ｐｏｗｅｒｖａｃｕｕｍｔｕｂｅｓｆｏｒｉｎｄｕｓｔｒｉａｌｈｅａｔ ｉｎｇ .ＩｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｔｈｅｒａｄｉｏａｃｔｉｖｉｔｙｏｆＴｈＯ2ｌｅａｄｓｐｒｏｂｌｅｍｓｔｏｉｔｓｍａｎｕｆａｃｔｕｒｅａｎｄａｐｐｌｉｃａｔｉｏｎ .Ｌａ2 Ｏ3 Ｍｏ ,ｏｎｅｏｆｔｈｅａｔｔｒａｃｔｉｖｅａｌｔｅｒｎａｔｉｖｅｓ,ｗａｓｉｎ ｖｅｎｔｅｄｉｎｔｈｅｍｉｄｓｔｏｆ 1970ｓ[1～ …     

Electrochemical flotation separation of chalcopyrite from molybdenite by CM Eh control

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭｏｌｙｂｄｅｎｉｔｅｉｓｏｆｇｏｏｄｎａｔｕｒａｌｆｌｏａｔａｂｉｌｉｔｙ ,ａｎｄｉｓｎｏｔｄｅｐｒｅｓｓｅｄｉｎａｗｉｄｅｐｏｔｅｎｔｉａｌｒａｎｇｅ (- 1.2～1.4Ｖ) [1] .Ｏｎｔｈｅｏｔｈｅｒｓｉｄｅ ,ｔｈｅｆｌｏａｔａｂｉｌｉｔｙｏｆｃｈａｌ ｃｏｐｙｒｉｔｅｉｓｄｅｃｒｅａｓｅｄｑｕｉｃｋｌｙａｔａｐｒｏｐｅｒｒｅｄｕｃｔｉｖｅｐｏ ｔｅｎｔｉａｌ.Ｔｈｅｒｅｆｏｒｅ ,ａｔｌｏｗｐｏｔｅｎｔｉａｌ,ｃｈａｌｃｏｐｙｒｉｔｅｃａｎｂｅｄｅｐｒｅｓｓｅｄａｎｄｍｏｌｙｂ…     

Mechanical behaviors of Fe_3Al with vanadium addition

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｉｒｏｎａｌｕｍｉｎｉｄｅＦｅ3Ａｌｏｃｃｕｒｓｗｉｔｈｉｎｔｈｅｒａｎｇｅｏｆ 2 4 %～ 32 % (ｍｏｌｅｆｒａｃｔｉｏｎ)ａｌｕｍｉｎｕｍ .Ｉｔｈａｓｔｈｒｅｅｐｏｓｓｉｂｌｅｓｔｒｕｃｔｕｒｅｓ:ＢＣＣ ,ｗｈｉｃｈｉｓｓｔａｂｌｅａｔａｂｏｕｔ 760℃ ,ｉｍｐｅｒｆｅｃｔＢ2 ｏｒｄｅｒｓｔｒｕｃｔｕｒｅａｔ 540～760℃ ,ａｎｄＤＯ3 ｏｒｄｅｒｓｔｒｕｃｔｕｒｅｗｈｉｃｈｉｓｓｔａｂｌｅｂｅ ｌｏｗｔｈｅｃｒｉｔｉｃａｌｔｅｍｐｅｒａｔｕｒｅｏｆ 540℃ .ＤＯ3 ｏｒｄｅｒ…     

HEAT TREATMENT STRENGTHENING EFFECTS OF RARE EARTHS ON Mg—9Al ALLOY

Mg-9Al-xRE magnesium alloys were studied, where, x is 0, 0.4. 0.8. 1.2 and 1.6% (in weight percent, wt%), respectively. Influence of rare earths (RE) on microstructure and strength in both T4 (solute heat treatment) and T6 (solute heat treatment and artificial ageing treatment) were investigated. Strength of specimen was tested at ambient temperature. The micro structure was analyzed by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction analysis. RE additions improved T4 tensile strength of the treated alloys. Small addition (0.4wt%) of RE greatly improved the strength of ageing treated (T6) Mg-9Al alloy, but further additions caused decreasing.     

混合稀土和挤压铸造对ZL305合金组织和性能的影响

采用挤压铸造和重力铸造制备出不同混合稀土含量的ZL305合金,研究了混合稀土含量和挤压铸造对合金微观组织和力学性能的影响。结果表明,在重力铸造下,添加混合稀土对合金晶粒细化效果明显,当添加0.1%的混合稀土时,ZL305合金的综合力学性能达到最佳,抗拉强度增加到227.88MPa,伸长率为6.47%。相比重力铸造,挤压铸造成形的合金组织明显细化,并且合金铸态的抗拉强度和伸长率都明显提高。添加0.2%的混合稀土时,合金的抗拉强度和伸长率最佳,分别为302.35MPa和7.23%。经430℃×10h固溶处理后挤压铸造合金的性能显著提高。     

Zn含量对7XXX铝合金性能及微观组织影响

为了深入研究7XXX铝合金的成分对材料性能的影响,对通过模铸工艺制备的高锌含量的铝基合金性能和微观组织进行了研究,重点探讨了Zn含量对合金组织、性能和铸造流动性的影响。研究结果表明,当Zn含量从20%增加到40%时:对材料组织的影响主要表现为晶粒尺寸由45μm减小到20μm,晶界处非平衡相α+η的体积分数由9%增加到28%;对力学性能的影响表现为抗拉强度与屈服强度升高,分别达到470 MPa和430 MPa,伸长率有所降低,从7%降低至3%左右,合金硬度值由75 HV提高至140 HV。同时,Zn含量的增加可以降低合金固相线温度,这有利于提高合金的流动性。     

Effect of rare earth on the microstructure and mechanical properties of as-cast Cu-30Ni alloy

Cu-30Ni-xRE (x = 0–0.213) alloys were prepared by a metal mould casting method. The effect of RE on the microstructure and mechanical properties of the alloys was investigated using optical microscope, scanning electronic microscope with energy-dispersive spectrometer, X-ray diffraction, and mechanical test. The results show that RE has obvious effect on refining dendrite structure and grain size, as well as on purifying the melting of Cu-30Ni alloy. With the increase of RE content, the ultimate tensile strength, yield strength, and elongation increase at first and then decrease after adding RE more than 0.095 wt.%. Cu-30Ni-0.095RE alloy possesses preferable mechanical properties, i.e., the ultimate tensile strength, yield strength, and elongation are 308 MPa, 125 MPa, and 51.2%, respectively. The microstructure and mechanical properties are worsened with increasing RE content more than 0.095 wt.%. The improvement of mechanical properties of Cu-30Ni-0.095RE alloy is attributed to RE refining microstructure and purifying the matrix.     

Investigation on the microstructure and mechanical properties of a cast Mg–6Zn–5Al–4RE alloy

Mg–6Zn–5Al–4RE (RE = Mischmetal, mass%) alloy was prepared by metal mould casting method. The microstructure and mechanical properties of the as-cast and heat-treated alloys were investigated. The results show that the phase compositions of the as-cast state alloy are supersaturated solid solution -Mg, lamellar β-Al₁₂Mg₁₇, polygonal Al₃RE and cluster Al₂REZn₂ phases. The mechanical properties, especially the ultimate tensile strength and elongation of the alloy were significantly improved by the heat treatment. Fracture surface of tensile specimens was analyzed by optical microscope and scanning electron microscope.     

Study of Melt Thermal-Rate Treatment and Low-Temperature Pouring on Al-15%Si Alloy

Under the condition of melt thermal-rate treatment (MTRT) and low-temperature pouring (LTP), the tensile properties of Al-15%Si alloy are improved, the average size of primary Si is refined to about 20 μm from about 50 μm, and eutectic silicon can be well modified. The ultimate tensile strength and elongation are 201 MPa and 3.5%, and these values increase by 12% and 25%, respectively, compared with that obtained by conventional casting technique. The Al-15%Si alloy modified with Sr and RE additions was also studied for comparison purposes. The tensile properties of the Al-15%Si alloy treated with MTRT + LTP are superior to those modified with Sr or RE addition individually. The eutectic growth temperature difference between modified and unmodified melts was used to indicate the modification level. The modification effect of MTRT + LTP on Al-15%Si alloy is better than that modified with Sr or RE addition.     

Influences of complex modification of P and RE on microstructure and mechanical properties of hypereutectic Al-20Si alloy

P and RE complex modification of hypereutectic A1-Si alloys was conducted. The influences of P, RE content on the microstructure and mechanical properties of alloys were investigated. The complex modifications of P and RE make the coarse block primary silicon obviously refined and the large needle eutectic silicon modified to the fine fibrous or lamella ones. P mainly refines the primary silicon, but excess P is unfavorable to the refinement of primary silicon. RE can well refine the primary and eutectic silicon, but its modification effect on the eutectic silicon is more obvious. P can repress the modification of RE on the eutectic silicon The alloys with the additions of 0.08% P and 0.60% RE have the optimal microstructure and the highest mechanical properties. Compared with the unmodified alloy, the primary silicon of alloys can be refined from 66.4 μm to 23.3μm and the eutectic silicon can be refined from 8.3 μm to 5.2μm. The tensile strength is improved from 256 MPa to 306 MPa and the elongation is improved from 0.35% to 0.48%.     

Effect of Sc and Sr on the Eutectic Si Morphology and Tensile Properties of Al-Si-Mg Alloy

To study the effect of Sc and Sr additions on modifying eutectic silicon particles and mechanical properties for Al-Si-Mg casting alloy, they were added with different amounts in F357 alloy without beryllium addition in the present work. It was found that (0.4 wt.% Sc and 0.04 wt.% Sr)-modified F357 alloy presented the optimal tensile properties when compared with the individual addition of Sc or Sr. This was mainly attributed to the synergic modification of eutectic Si in F357 alloys due to the combined additions of Sc and Sr. The silicon modification mechanisms via Sc and Sr were emphasized to be examined in this paper, and the fracture mechanism of the obtained alloys was also discussed.     

稀土元素Y和Nd对Mg-Zn-Zr系合金组织和性能的影响

对添加稀土元素Y和Nd的Mg-Zn-Zr系ZK60变形镁合金进行了热轧及热处理,测试了ZK60合金及ZK60RE合金室温拉伸性能,采用金相显微镜、扫描电镜和X射线衍射等分析方法观察了合金不同状态下的显微组织。初步探讨了微量稀土元素Y和Nd在ZK60合金中的存在形式和作用机理及其不同成分对该合金组织与力学性能的影响。结果表明,稀土元素Y和Nd均能够细化ZK60合金的铸态组织,使其室温断裂强度大幅度提高。其中主要化学成分（质量分数,％,下同）为Mg-5．5Zn-0．7Zr-0．5Y-0．5Nd和Mg-5．5Zn-0．7Zr-0．6Y-0．6Nd的合金强化效果显著,比未添加稀土元素的ZK60合金室温断裂强度分别提高了14．94％和20．2％。     

混合稀土对Mg-5Al-1Si组织及性能的影响

研究了不同组分含量的混合稀土对Mg-5Al-1Si合金高温蠕变性能的影响，对析出相进行了鉴定。研究结果表明，分别加入富镧及富铈混合稀土以后，合金中Mg2Si相得到细化；力学性能检测结果表明，室温及150℃拉伸性能均明显提高。同时，在微量混合稀土及Mg2Si相的综合作用下，含不同混合稀土的Mg-5Al-1Si合金的抗高温蠕变性能均超过AE42。