Aluminous

Summary: Agitate friction welding is a kind of new-style solid photograph solders method, in heterogeneous material join respect has wide applied perspective. The craft that the article chafes from agitate, function and constituent tripartite face introduced aluminium respectively - the research of steel agitate friction welding makes progress, for its thorough research provided a basis. Use agitate friction welding, heterogeneous metal is aluminous - steel can realize join, but limits of craft parameter choice is lesser, when edge of steel park advancement, aluminous - steel joins more easily. As a result of aluminium - the difference of steel physics function, both flow condition is different, two side present solder nucleus different structure, the mechanical function of contact is reduced as a result of the existence of the compound between brittleness metal. Be inputted through changing heat or add the 3rd group yuan of method that waits for microelement is OK the mechanical performance that improves joint. Preface is carried in aerospace, traffic, shipping is made in waiting for industry, to reduce weight, managing the sources of energy, lower contented and cost, different work requirement, of heterogeneous material solder the technology gets increasingly the attention of people [1] . Use aluminium and aluminium alloy density small (the 1/3 that is steel about) , corrosion resistance, heat conduction leads as good as conductivity dominant position, replace steel to be able to reduce the weight of structural member with aluminium alloy, in heavy equipment light quantify a respect to have good application perspective, how to solve aluminium however - steel is heterogeneous the join between material is the crucial question that decides its safety is used. Current, aluminous - the in basically joining the method has fusion welding explosion solder of steel [2] , laser beam welding [solder of drill rod of 3] , frit [4] , still have friction welding of solid photograph connective [5] . Normally explosion solders to apply to aluminium only - steel answer plywood. Use laser beam welding and frit - when drill rod solder, because difference of function of the melting point of aluminium and steel, heat conduction is very big, the compound between the metal of a variety of brittleness is formed easily in contact intermediate zone, the connect of unavailable high quality. Rotate friction welding solders aluminous - steel applies to column form material only again, contact accepts restriction. All sorts of methods assure above hard preparation gives the aluminium with good quality - steel solders contact, restricted its large-scale application. Agitate friction welding (Friction Stir Welding, FSW) it is method of a kind of new-style solid photograph join, have efficient, environmental protection, heat is out of shape and leftover stress is little wait for integrated advantage [6] . It is to use the attrition heat between agitate head and workpiece, general the melting point under mother capable person, because this solders,the workpiece in the process did not fuse, with the tradition solder methodological photograph is compared, can avoid the constituent flaw such as stomatic, crackle effectively. In addition, agitate friction welding does not get data basically the influence of the element such as physico-chemical function, mechanical function and crystal structure, difference of function of different to overcoming material brings solder difficulty has huge advantage [7] , have wide perspective in heterogeneous metal join accordingly, relevant mechanism studies also more and more be taken seriously. Article general from craft, organization, function 3 minutes of faces analyse aluminium - the research current situation of steel agitate friction welding. 1 aluminium - steel process and parameter 1.

1 agitate head is in agitate friction welding, the dimension of agitate head and appearance flow to quality of welding line figuration and metal have main effect. In aluminium - in the process of agitate friction welding of steel, because the hardness of steel is bigger, and melting point is controlled for 1500 ℃ , because the material of head of this pair of agitate raised taller requirement, have namely good high temperature resistant reach wearability in order to improve the service life of agitate head. The agitate head of right stuff can increase attrition, raise caloric to input, be helpful for welding line metal model is changed and rising solder quality. Show according to document, can use as aluminous - the agitate head material of steel agitate friction welding is very much, the tool steel that is like heat treatment [steel of 8] , mould [9, 10, alloy of 11] , nickel radical [alloy steel of 12] , Wc-co [13] . Install Jing Liming [the agitate head that still used combination of two kinds of material 14] : Axial shoulder uses mould steel, bougie material is Wo -co alloy steel, the wearability that raised agitate head effectively and produce quantity of heat. 1.

2 crafts parameter is told commonly, the craft parameter of agitate friction welding basically has agitate head rotate speed coming back to spend N, solder the amount is controlled below advancing speed V and axial shoulder. Because heterogeneous material is in,melting point, hot coefficient of expansion and heat conduction lead the vast difference of the respect, a large number of wearing away and make sure to avoid agitate data is OK and sufficient of the head confluence is together, aluminous - when steel is butt joint connect, solder craft parameter still includes bougie to solder relatively the X of deflection quantity Δ of juncture. Graph 1 measure sketch map for bougie deflection. Its craft parameter can offer proper hot input for weldment, get exterior figuration good, interior solders flawlessly contact. As a result of aluminium - the physical function of steel differs too big if express 1 show, because this chooses appropriate parameter to realize aluminium - the reliable join of steel is special difficulty, especially thick board parameter choice, because thick board temperature of agitate friction welding distributings, plasticity flow and figuration mechanism and thin plate have very big different. In agitate friction welding, in the attrition of oversight agitate head and workpiece hot circumstance falls, hot input can express [14] : Among them, q: Solder hot input quantity, μ : Coefficient of friction, p: Perpendicular pressure, r: Axial shoulder radius, n: Rotate speed coming back is spent, v: Advancing speed. Among them caloric input basically depends on rotate speed coming back is spent (N) with advancing speed (V) ratio. Will tell commonly, rise to rotate speed coming back is spent or lower advancing rate inside proper limits when, the heat that adds welding line inputs a quantity, be helpful for model of welding line material changing, falling less press a quantity to be able to get the connect with good quality. But if the value of N/v is too great, hot input approachs the melting point of material, send welding line metal easily too model is changed, affected the flow of welding line metal, cannot form good joint. Study the result makes clear, the meeting when raising hot input increases ply of the compound layer between aluminous steel metal, reduce apparently solder contact function [14] . Additional, spend when rotate speed coming back inferior perhaps advance when rate is older, hot input of welding line area is lesser, all round agitate needle material (especially steel side) change without sufficient model, cannot realize aluminium - the agitate attrition of steel solders, the likelihood appears " the kiss is received " blemish. At present aluminous - in research of steel agitate friction welding, if main craft parameter is expressed 2. Can see, in butt welding, along with the addition of weldment ply, craft parameter chooses limits narrow, the value of N/v is taken commonly 10 the left and right sides. Photograph comparing receives contact at be opposite, the selection of craft parameter limits of lap joint is wider. 1.

Of 3 material set the position in connect of butt joint of friction welding of heterogeneous material agitate, affect welding line quality still have solder the relative position of workpiece [23] , edge of advancement of agitate friction welding and the temperature that return an edge are different, temperature of wh which direction is returned high without final conclusion, because rate of this heat conduction differs,old heterogeneous stuff is having main effect to welding line quality relative to the position. Think melting point taller metal is put in a side with high temperature commonly more the model that is helpful for a metal is changed and flow, win ideal contact, can bring about material of low melting point to fuse otherwise, influence metal flows, and the weldment of high melting point did not achieve model to change position however, reduce the quality of contact badly. In aluminium - in the experiment of agitate friction welding of steel, put steel in progressive edge commonly, and when aluminous park returns an edge win the contact with good figuration more easily. FUKUMOTO[13] refers to this commentate: In agitate attrition, plasticity metal moves along with agitate needle and flow, be like an edge of steel park advancement, aluminous park returns an edge, the aluminium of plasticity condition flows along agitate needle already in the steel that model converts, make sure both reacts adequately shirt-sleeve, form good joint thereby (graph 2a) . Conversely, the aluminium that model melts is entered along with agitate head not in the steel that model converts, aluminium alloy needs to overcome greater resistance and steel to mix, in agitate friction welding, model changes the stand or fall of metallic flow performance to deciding the stand or fall of contact quality directly, because this cannot form good joint (graph 2b) . Differ with this, nanchang aviation university Professor Xing beautiful [12] undertook aluminium - the research of agitate friction welding of steel, discover steel is returning an edge, aluminium can get the connect with good quality more in progressive edge, the analysis thinks process of agitate friction welding is medium, return what model melts a metal all round edge bougie to be out of shape direction and flow of metal of solder nucleus area agree, of the metal of mother capable person that model melts all round progressive edge bougie be out of shape of direction and press press of metal of solder nucleus area be out of shape way is opposite. To lap joint, the underside that is a steel park aluminium commonly [10, 19] . Nextpage anyhow, use technology of agitate friction welding, the aluminium with bigger difference of physics, chemical function - steel can solder, but limits of optional craft parameter is lesser. In butt joint connect, spend through changing rotate speed coming back, solder of distance of speed, deflection and material set the position, can improve the quality of contact, aluminous - what steel agitate friction welding needs N/v to be in 10 the left and right sides, when edge of steel park advancement, aluminous - steel joins more easily, in lap joint, use appropriate craft parameter to be able to get the connect with good quality. The mechanical function of 2 connect 2.

1 drawing function is in aluminous - in the agitate friction welding of steel, the tensile strength of butt joint connect relatively difference of mother capable person is not very big, tensile strength falls in appropriate craft parameter even capable person of prep above mother. Strain crack happens in solder nucleus and steel side heat engine to affect face of have a common boundary to be in commonly, because produced the compound between the metal of hard brittleness, because this ruptures with brittleness commonly,give priority to. The intensity that the content of the compound between hard brittleness metal in contact is affecting joint directly [17] , contact tensile strength is reduced along with the growth of ply of the compound between the metal. The formation of the compound between the metal and solder hot input has close connection, hot input increases the form that quickens brittleness compound nucleus and grown, raised aluminium - the content of compound of brittleness of face of steel have a common boundary, reduce the drawing performance of contact finally, if pursue,3 are shown. In addition, very big concern also exists between contact intensity and microcosmic organization, grain is pettier, intensity is higher. Aluminous - needle of agitate of steel agitate friction welding is main deflection aluminous side, aluminous side of solder nucleus area gets the heat engine action of agitate friction welding, produce dynamic recrystallization, form petty grain waiting for an axis, intensity is very high, and rate of steel side heat conduction is low and melting point is higher, solid look line is more aluminous a lot of taller, because this is in what had an element only in contact,diffuse and the reaction between tantalum, make brittleness thing, intensity is inferior, if pursue,4 are shown. Aluminous - intensity of connect of steel agitate friction welding is reduced because of the existence of the compound between the metal, the content that how reduces compound perhaps uses the compound between the metal with better tenacity to already made the central point that academia pays close attention to. According to the formation of brittleness compound the characteristic is mixed function, can input a quantity through controlling heat on one hand, make temperature is in aluminous - steel in all under brilliant temperature, but the plasticity that may affect weldment flows. The strength that can add the 3rd kind of material or alloying element to improve joint between weldment on the other hand [24] . 2.

2 microscopical hardness is shown 5 times like the graph, the average hardness of area of nucleus of solder of butt joint connect is taller than mother capable person and distributing inhomogenous, because the compound between the metal in welding line distributings,this is inhomogenous, the local hardness that the compound between the metal exists is far the talent that compare a mother is high. Nextpage wants than mother capable person in the hardness of area of steel side TMAZ tall, the TMAZ hardness of capable person of aluminous side mother wants than aluminium alloy low, and hardness of hot influence area relatively mother capable person is reduced somewhat, have bate tendency, its reason may be to solder the organization below hot loop action produced change in the process [20] , aluminous - steel hardness peak value goes out to solder now contact is mid. Lap joint hardness still does not have relevant research. The place on put together is narrated, as a result of aluminium - the compound between blemish of the existence in steel agitate friction welding and hard fragile metal, contact intensity is reduced somewhat, welding line area hardness profile not all and local taller, contact hardness peak value appears in the heat with mid connect to affect an area. 3 microcosmic organizations solder process companion is conducted as caloric, solder because contact and mother capable person are defeated to caloric differs and producing constituent change. In butt joint connect, what divide according to be being organized is different, aluminous - connect of steel agitate friction welding can differentiate 7 area, namely steel mother capable person (BM) , steel side heat affects an area (HAZ) , steel side heat engine affects an area (TMAZ) , solder nucleus (WNZ) , aluminous side heat engine affects an area (TMAZ) , aluminous side heats up influence area (HAZ) , aluminous mother capable person, if pursue,6 are shown. In aluminium - aluminous side puts cross section of connect of butt joint of steel agitate friction welding in apparent onion annulus flow form, steel is in solder nucleus area is irregular distributing, having apparent interface. Lap joint affects an area without clear onion link and heat engine, by composition of petty grain waiting for an axis. Because area of heat engine influence suffers plasticity flow and hot double effect, grain of capable person of aluminous mother of grain of area of influence of aluminous side heat engine spins rotate 90 ° , and steel side by tooth needle model spin grain composition, the grain of hot influence area is somes solder nucleus area is larger more opposite. No matter be,still building in the butt joint in receiving, aluminous - what steel agitate friction welding produced an element between mother capable person and solder nucleus is migratory. Because aluminous atom is active the atom that compare iron is relatively active, side of aluminous Xiang Gang is migratory and opposite sufficient. Get the intense agitate extruding force of agitate needle, the fragment of a lot of steel exists in solder nucleus, steel is in aluminium solubility is dinky, below room temperature scarcely dissolve in aluminium, but steel and aluminium not only can fashion solid solution, still can form the compound between the metal, the aluminium in iron formed FeAl3 of the compound between the metal to wait [18] , because function of head of this this butt joint produces adverse effect, and lap joint, use galvanization steel and aluminium solder can reduce the reaction between aluminous iron, the performance that improves joint [16] . In butt joint connect, as a result of aluminium - the difference of steel melting point, fall in force of agitate of diverse mix head and hot input action, two side present solder nucleus different structure. Steel side and solder nucleus have clear dividing line and the interface is a curve model, and aluminous side finishs dynamic crystallization below agitate needle action, solder nucleus and aluminous mother capable person do not have apparent end, aluminous to receiving contact solder nucleus to basically be in side, solder nucleus center is mixed by the aluminium of recrystallization broken steel composition, still observed circinate flows configuration [20] . Aluminous - the area of nucleus of solder of agitate attrition lap joint of steel two side, steel formed be similar in shape in capable person of aluminium alloy mother " forceps " or the turn distributings falcately, steel clutchs as forceps solder nucleus aluminium alloy [12] , if pursue 7. Solder nucleus area basically is layer shape connect, in solder nucleus vertical sectional and considerable examine arrives " toothed " appearance [18] , if pursue 8. Below the action of temperature and agitate force, aluminous along agitate head backward migratory, and the steel that model converts moves up along agitate head, move headlong as agitate, the aluminous steel of plasticity condition is met backward fill cavity, form the compound between the metal with iron, form " toothed " stripe. In the agitate friction welding of heterogeneous metal, because material physics is mechanical of function different, pattern of metallic plasticity flow is different, thereby dynamic crystallization level is different. Be like solder nucleus area, steel basically exists with broken grain, and aluminium produces dynamic recrystallization, grain is pettier. The volume that hot input measures and cooling rate are affecting dynamic recrystallization of the metal directly, also spend with rotate speed coming back namely, quantity of advancing speed, deflection is concerned. In aluminium - in the agitate friction welding of steel, aluminous melting point is inferior, solder the enough of quantity of heat of the generation in the process makes its produce dynamic recrystallization, but the steel that can't make melting point higher produces persistent crystallization. In addition, the coefficient of thermal conductivity of steel is aluminous 1/3 probably, make the temperature of steel side elevatory rate is very slow, happen to change hard, need is bigger be out of shape can produce dynamic recrystallization with temperature ability. When soldering below plasticity condition, two kinds of material are intense mix and present configuration of fold of eddy current shape, metallic bond can be formed in interfacial place [25] . Aluminous - the compound between the metal of connect of steel agitate friction welding has FeAl, FeAl3 and Fe2Al5 to wait commonly. Heat engine affected area and place of face of solder nucleus have a common boundary to build metallic compound layer, the ply of metallic compound layer is not to jump over poor performance to had been jumped over, achieve in the performance ability of the connect inside certain limits however optimal. In agitate friction welding, the change of craft parameter is right of the compound between the metal distributing having main effect, this is affecting the position that contact ruptures directly. The place on put together is narrated, aluminium - connect of steel agitate friction welding is become by 7 section namely steel mother capable person (BM) , steel side heat affects an area (HAZ) , steel side heat engine affects an area (TMAZ) , solder nucleus (WNZ) , aluminous side heat engine. As a result of aluminium - the difference of steel flow performance, two side present solder nucleus area different structure, solder nucleus and steel have apparent have a common boundary, and compare with aluminous side have a common boundary smooth, in solder the nucleus is in and the place of face of have a common boundary of solder nucleus and steel is existing the compound between a variety of metals, intensity of head of its content butt joint has very big effect. 4 last words 4.

1 heterogeneous metal is aluminous - steel can solder through agitate friction welding, but aluminous - the limits of craft parameter choice with steel agitate optional attrition is lesser, lap joint is righter receive contact parameter limits to want some wider, in butt joint connect, spend through adjusting rotate speed coming back, solder of distance of speed, deflection and material set the position, can improve the quality of contact, aluminous - what steel agitate friction welding needs N/v to be in 10 around, when edge of steel park advancement, aluminous - steel joins more easily. In lap joint, use reasonable craft parameter to be able to get the connect with good quality. 4.

2 aluminium - the performance that the existence of the compound between metal of connect of steel agitate friction welding reduced contact, can be measured through controlling hot input or join the 3rd kind of material to reach those who add microelement to affect the compound between the metal to generate, increase the strength of contact. Area of contact welding line hardness profile not all and local taller, contact hardness peak value appears in the heat with mid connect to affect an area, the likelihood was to generate hardness to be worth the compound between taller metal. 4.

3 aluminium - steel agitate friction welding is comprised by 7 areas, namely steel mother capable person (BM) , steel side heat affects an area (H- AZ) , steel side heat engine affects an area (TMAZ) , solder nucleus (WNZ) , aluminous side heat engine affects an area (T- MAZ) , aluminous side heat affects an area (HAZ) with aluminous mother material. As a result of aluminium - the difference of steel flow performance, two side present solder nucleus area different structure, solder nucleus and steel have apparent have a common boundary, and compare with aluminous side have a common boundary smooth, in solder the nucleus is in and solder nucleus and steel boundary exist the compound between a variety of metals, intensity of head of its content butt joint has very big effect. CNC Milling