| Magnesium alloys have high potential for use as components in automobile, electronicdevice and aerospace application because of their low density, high specific strengthen, goodelectromagnetic shielding and good damping properties. There is abundant resource ofmagnesium on the Earth. In recent years, the request of energy saving and environmentalprotection has promoted the rapid growth of magnesium alloys. Nowadays, most of themagnesium alloy products are produced by die-casting but they have low mechanicalproperties. Wrought magnesium alloys attract a lot of attention world wide because theypossess good mechanical properties such as high tensile strength and high elongation. Thisarticle take AZ80 and ZK60 two kind of typical high strength distortions magnesium alloys asthe research object, inspected the effectiveness for a period of time heat treatment craft to themicroscopic organization and mechanics performance influence, and has conducted theresearch to the material effectiveness for a period of time strengthening mechanism and thebreak behavior.The present paper through the suitable heat treatment regime, the use light microscope,the scanning electron microscope, and method and so on mechanics performance aircraft, takethe pulling test and the normal temperature impact test as the content, the synthesis discussesthe melting effectiveness for a period of time standard to separate out the shape and thedistribution thus affects the alloy mechanics performance, obtained the following findings: (1)AZ80 magnesium alloy degree of hardness elevates along with the effectiveness for aperiod of time temperature increasing, but toughness reduces actually along with temperatureincreasing;it's tensile strength σb, the yield strength σ0.2, the limit of proportionalityσp,elongation ratio δ and the reduction of area φ has the similar whole change tendency, whichbasically changes the tendency for along with effectiveness for a period of time temperatureelevating, after increases first reduces, in 170 ℃ reach the peak value;Quite is all high in140-200 ℃ effectiveness for a period of time alloy above performance. Above forms theconclusion reason: According to the phase diagram analysis, in the casting conditionMg-Zn-Al alloy mainly has Mg17Al12 and Mg-Zn. We may see from the AZ80 magnesiumalloy microstructure, along with effectiveness for a period of time temperature elevating,because the second phase Mg17Al12 uncontinuously separates out at first, then transforms forseparating out continuously, at last forms the net structure. Becauseβ-Mg17Al12 in lowtemperature aging is soft, plays does not grip the crystal boundary to the nail the role,therefore the Mechanics performance drops, thus alloy toughness high, degree of hardness islow. The second phase β -Mg17Al12 forms the netted distribution the temperature range tobe higher than 170 ℃,The organization assumes when the lattice mechanics performance allquite is bad, 170 ℃ is its effectiveness for a period of time temperature. The AZ80magnesium alloy fracture mainly assumes the rivers shape pattern, therefore its normaltemperature break belongs cleaves the break. Along with effectiveness for a period of timetemperature increment, the fracture rivers shape pattern by the tiny in disorder transformationfor the trend consistent thick laminated shape, crisply breaks the nature to intensify. We cansee from organizes of it, when high temperature forms the network structure, brittle Mg17A112continuous distribution in crystal boundary, if has the crack source existence, the crackextremely easily expands along the lattice, thus causes the material the brittle fracturetendency to increase.According to above mechanics performance changing rule, we can conclude that in140-170 ℃ synthesis mechanics performance is high, therefore what the AZ80 magnesiumalloy is suitable the aging treatment of metal temperature is 170 ℃ or so.(2) ZK60 magnesium alloy degree of hardness and resilience along with effectiveness fora period of time temperature elevating, presents the opposite change tendency, the degree ofhardness will elevate at first then lower, it will reach the biggest in 170 ℃;However, theresilience reduces firstly then increases, which is lowest in 170 ℃, In addition degree ofhardness changes quickly in 140-170 ℃, But the resilience quickly changes in 110-170 ℃.ZK60 magnesium alloy when low temperature effectiveness for a period of time has the highresilience, other mechanics performance (for example tensile strength, yield strength,elongation ratio, reduction of area, degree of hardness, limit of proportionality and so on) in140-170 ℃ have the high value. The ZK60 magnesium alloy normal temperature breakbelongs cleaves the break. This alloy is suitable in 140200 ℃ carries on the aging treatmentof metal.In addition, compared AZ80 magnesium alloy through the analysis discovers with theZK60 magnesium alloy organization performance: Z80 and ZK60 magnesium alloysbecause the increase element is different (AZ80 host increase element is Al, ZK60 hostincrease element is Zn), thus causes its organization distribution and the shape difference.ZK60 as a result of joins Zr but crystal grain AZ80 is tinier, therefore under the usual situation,its intensity equipollent study performance AZ80 is higher, Moreover, AZ80 magnesium alloyhas the same spot with the ZK60 magnesium alloy organization performance:(1) ZK60 and the AZ80 alloys are all good because of the middle aging temperature(140-200℃) the section effectiveness for a period of time plasticity, the plasticity is consistentalong with the temperature change tendency.(2) When ZK60 and the AZ80 alloys microscopic organizes are lattice, the performanceis worse.
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