Airborne equipment uses aviation Al7Si0.3MgTiSb of high grade aluminium alloy

The alloy of 3MgTiSb changes principle, function and founding craft characteristic. Pointing out this alloy is the heat treatment with a kind of mechanical function and good technical properties cast aluminium alloy, agree with production Bao Bi, accurate aviation is airborne equipment structural member. Keyword: Aluminium alloy casts airborne equipment [Abstract]In This Paper, alloying Principle, properties And Melting-casting Technology Of AL7Si0.

3MgTiSb Are Introduced.

It Is Pointed Out That Al7Si0.

3MgTiSb Is A New Kind Of Casting Aluminium Alloy, which Has Excellent Mechanical And Technological Properties Under The Condition Of Heat Treatment, and Is Suitable For The Precise, thin-walled Component Used For Airborne Equipmentin In Aviation.

Keywords: Aluminium Alloy Casting Airborne Equipment1 is summarized to raise aviation the function of airborne electron equipment reduces production cost, structural member of airborne electron equipment to quantify directional development integration, gently. This asked objectively to drive the progress that casts a technology without nicety of surplus aluminium alloy nearly. With deft and beautiful whole nicety cast replaces the solder that use drill rod, connection the structural member that spells outfit combination. Forming development trend gradually. Material is one of keys that win high grade cast. The aluminium alloy that is used at airborne equipment should have very good integrated and mechanical property, organize air-tightness and foundry technology sex. The article basically will introduce Al7Si0.

The alloy of 3MgTiSb is changed principle and undertake to this alloy grain is refined, degenerative processing, improve the newest research result of alloy function substantially. 2 alloy change principle 　 Al7Si0.

3MgTiSb alloy by Mg is added to develop in alloy and come in Al-Si n duality. Thirdly yuan alloy phasor is shown 1 times like the graph. Can see according to phasor, this alloy is in after the balance is caky (Al) + inside the two-phase area of Si. But as a result of lopsided caky result, its are comprised will be (Al) + Si+Mg2Si. Graph 2 for the graph 1 in of Al-Mg2Si perpendicular and sectional. Can see, mg2Si rises along with temperature in the solubility in solid solution and increase quickly, it is OK so the alloy of through solid dissolve heat treatment aggrandizement. Mg2Si is a kind of crystal lattice complex, have cubic structure, space group the compound that is Fm3m. When solid dissolve quenchs, mg2Si first dissolve enters matrix in. It is after that in process of effectiveness for a given period of time, the GP division that forms petty dispersion to distributing from inside matrix keeps abreast of and development is transfer, make alloy gets aggrandizement thereby. Graph 1 　 Al-Si-Mg3 yuan horn of alloy phasor rich aluminium pursues 2 　 Al-Si-Mg2Si of Al-Mg2Si phasor 　 3 yuan in all the balance temperature of brilliant face is 555 ℃ , and rather than is balanced in all brilliant temperature wants under this temperature, so temperature of top firm dissolve can be taken only control for 535 ℃ . Right now, mg is in the balance solubility in matrix 0.

6% . And fall in actual condition, want to be worth under this. The volume that be like Mg is too high, cannot originally the leftover and bulky Mg2Si photograph of dissolve will distributing in crystal boundary, lower the outspread rate of alloy quickly. The Mg quantity in reason alloy is certainly 0.

3% the left and right sides. The element such as Ti, B, Zr, V, Nb, Cr has the effect that refines grain, but the effect with Ti relatively beautiful. Graph 3 for Al-Ti alloy phasor. See by the graph, a few Ti are joined in alloy, can produce Bao Jing to react namely, the TiAl3 particle of a large number of petty, dispersion arises inside the liquid. TiAl3 and Al are cubic brilliant department, crystal lattice kind is same, close of crystal lattice constant. So, tiAl3 can serve as crystallization core, (Al) will depend on in nucleus of the form on TiAl3. Graph Fe of 　 of phasor of alloy of 3 　 Al-Ti is the harmful impurity in alloy. Fe exists with the form of brittleness compound Al9Fe2Si2 in alloy, its configuration is bulky a shape or acicular. Rise in alloy cut apart the action of matrix, serious aggravation combines mechanical function of gold, especially outspread rate. In the meantime, still reduce the corrosion resistance of alloy. So, answer the quantity that contain iron to be controlled strictly, should restrict commonly in 0.

18% the following. Alloy of experiment of 3 tests result is used high pure Al, high pure Mg and crystallization Si are made up. Grain is refined employ Al-5%Ti-B alloy, in all of brilliant Si refine (degenerative) employ Al-5%Sb master alloy. Alloy undertakes fusion in resistor furnace. Make up prefab ingot first, pouring Cheng Xiaoding piece, next fast remelting, use flux - craft of pelagian combination fine undertakes dividing miscellaneous except gas, after quiet place 10min pouring sample. Graph the relation of content of the 4 Ti in be alloy and grain dimension. Can see, be more than when Ti content 0.

15% when, grain already got be refininged significantly. Be in about 0.

15% ～ 0.

3% reach the least value. But the affiliation of Ti is measured cannot overmuch, lest produce TiAl3 to slant analyse, lose blame all pledge the action of form nucleus. Graph the relation of content of 4 　 Ti and alloy brilliant granuality has research to make clear, grain is refined have time effect. Because the proportion of TiAl3 is larger, long heat preservation mixes the assemble that makes TiAl3 compound grown, chunk arises in the bottom of crucible piece shape TiAl3, those who cause grain is again thick change. Accordingly, answer after fusion as soon as possible mould ends. Of alloy pure spend and uniformity is influential to the stability of function. Use associated fine law to normally than onefold fine method smaller function mean square is differred. Use when low pressure is pouring, because fluid of the metal inside stalk is periodic circumfluence will be right the alloy fluid in crucible produces mix effect, conduce to those who reduce TiAl3 slanting analyse; When gravity is pouring, answer to have artificial mix timelily. The mechanical function of alloy depends on not just of grain refine degree, and also with in all the dimension of the Si in brilliant organization and configuration are concerned. Metallic Sb is a kind in all of brilliant Si refine an agent. Be cast in metal mold or below fast cold condition, the Sb of minim is joined in alloy, can make in all brilliant Si gets be refininged significantly, improve mechanical performance. Be in especially heat treatment (T5 or T6) hind, its plasticity index gets twice grows. By the graph 5 with the graph 6 can see, the affiliation of Sb is measured cannot overmuch, will make function is reduced otherwise. Sb spends minimum in the solid dissolve in Al, arise in 657 ℃ in all brilliant reacts (L → Al+AlSb) . After Sb is joined in Al, form AlSb compound namely. Reason somebody thinks, alSb and Si all belong to cubic brilliant department, constant of Ju Jing case is very adjacent. So, alSb can serve as the crystallization core of Si. Also somebody thinks, as a result of,be of Al-AlSb in all brilliant temperature compares Al-Si in all brilliant temperature wants tall, caky when Al-AlSb first in all partial crystallization goes out, generation is many and petty in all brilliant group serves as Al-Si in all the crystallization core of brilliant and make in all brilliant organization gets refining. From the point of the angle of crystallography, join Sb and join the degenerative element such as Na, Sr to differ. Sb is not changed in all the crystallization configuration of brilliant Si. So, say strictly, sb just refines an agent and not be alterative. Graph the influence of 5 　 Sb to tensile strength (T5 condition) Sb is opposite 6 　 of graph the influence of alloy outspread rate (T5 condition) the application of 4 alloys looks from applied angle, outside the use demand with should be satisfied particular besides the function of alloy, the fluidity of alloy, inspiratory waiting for foundry technology function with loose tendency is the problem that people cares most. Consider to make clear, of this alloy fill model fluidity, fight inspiratory oxidisability and air-tightness all the degenerative element such as excel Na, Sr, but effect of existence cooling rate. Accordingly, the following problem should note on craft: ① aviation is airborne facility construction cast is a feature with Bao Bi, nicety, need to use cast without surplus nearly, be like die-casting, pressure regulating casting of essence of life or metal mold cast a method. Cast cooling rate is older, it is better to can get refine the effect. Should adopt to the large large part that heat up a section stimulate cold measure. ② is in caky and characteristic respect, this alloy incline to at concentration loose. Accordingly, should undertaking cast is filled only, when filling construction of system and craft are designed, the order that assures cast is caky give fill adequately shrink, can acquire an organization the cast with compact, tall air-tightness. Because Sb oxidizes rarely in alloy and ③ burns caustic, so its refine action to have lasting effect sex. Alloy is OK for many times remelting, when burden calculation. In must considering foundry returns already some quantities that contain Sb, give right amount complement next. ④ this alloy can be used cast quench directly craft. When cast temperature refrigeration comes when the solid look line under alloy, enter its temper by dipping in water cooling medium directly in, attainable very good solution treatment effect. To the spare parts with dimension stability high demand, after solution treatment, still can undertake microtherm is handled circularly. The place on put together is narrated, al7Si0.

3MgTiSb alloy is the heat treatment with a kind of good integral performance cast aluminium alloy. Adopt proper heat treatment technology, mechanical function can be adjusted inside big range, have high outspread rate especially. This alloy agrees with especially substrate of plug-in unit of support of crust of appearance of the casing that makes airborne equipment, instrument, structure, circuit and microwave parts of an apparatus are waited a moment. CNC Milling