CN1616182A - Medium temperature Ag base brazing filler metal and its preparing method - Google Patents

Abstract

The medium temperature silver base brazing filler metal consists of: Ag 29.5-30.5 wt%, Zn 31.5-32.5 wt%, Mn 2.5-3.5 wt%, Sn 2.5-3.5 wt%, P 0.4-0.8 wt% and La 0.2-0.4 wt% except Cu. The preparation process includes the following steps: selecting material, material throwing and smelting, casting, extrusion and drawing. During the step of material throwing and smelting, electrolytic copper and P-Cu alloy are first heated quickly inside furnace for complete melting, covering agent is added, Zn, Cu-Mn alloy are added successively, Ag and Sn-La are added after lowering the temperature, and the temperature is finally raised to 1050-1100 deg.c while stirring before tapping. The product has the features of no harmful elements contained, relatively low cost, short production process, stable quality and raised extrusion and drawing finished product rate.

Description

Warm Ag base solder and preparation method thereof in a kind of

Technical field:

The present invention relates to a kind of no cadmium Ag base of novel low-cost temperature solder prescription that is used for ferrous metal, non-ferrous metal and carbide quartz welding and preparation method thereof.

Background technology:

Nearly 30 years, China's Development of China's Urbanization constantly advanced, and people are from the rural exodus to cities and towns, and the demand of the urbanization means of livelihood that match with it rapidly increases.For example, be lasting rising of household electrical appliance demand of representative with refrigerator, air-conditioning, building and ornament materials and manufacturing industry thereof are also flourish, and soldering tech has been played the part of the key player in these emerging industries.According to incompletely statistics, only the annual consumption Ag solder that needs has 100 tons in the household electrical appliances manufacturing nation, and the domestic annual Ag solder that need consume of construction material machining tool has 200 tons.In order to pursue brazing manufacturability and Technological Economy, soldering person usually preferentially selects for use the Ag base to contain the cadmium solder, and the production of the accessory that especially freezes is almost all adopted to contain the cadmium solder.This is owing to add Cd can show the liquidus curve that reduces alloy, dwindle molten temperature region, improve brazing manufacturability in the Ag-Cu-Zn ternary alloy three-partalloy, so Ag-Cu-Zn-Cd establishes one's own system in the early stage Ag base solder, has brought into play important function in the soldering of ferrous metal, non-ferrous metal and carbide alloy.Yet, contain the health that a large amount of uses of cadmium solder not only directly endanger the welding operator, also influence surrounding enviroment, containing the production of cadmium solder and using has become a global environment problem.Develop novel solder without cadmium, the exploitation new solder without cadmium soldering tech become the historic mission that solderer author bears.

Spectacles industry is the relatively advanced industry of China's light industry technology, and the output of tens million of covers is arranged every year, the output value reach several hundred million units (only in area, Wenzhou, annual sell reach three to 400,000,000 yuan more than) wherein major part export to foreign countries.The brazing material of welding glasses according to statistics every year will be with more than 200,000,000 yuan in area, Wenzhou, and the statistics in the whole nation are considerable especially.Spectacles industry also is an emerging industry in China, and development is fast, high efficiency, along with the development of society, and the raising of people's living standard, people pay attention to day by day to the protection eyes, and glasses class, consumption rise every year, and the development prospect of spectacles industry is immeasurable.The present spectacle frame and the making of other many ornaments be extensive use Alpaka and packfong all, especially packfong is owing to have Ag white beautiful appearance, and high temperature resistant, high resiliency, good physical and chemical performance such as corrosion-resistant, and be widely used in aspects such as making medical equipment, ornament and spectacle frame.Yet, all contain nickel element in the above-mentioned alloy, and nickel element has sensitization reflection and carcinogenic tendency to human body.Though nickel is the indispensable trace element of people's normal body, long-term contact nickel and nickel salt will cause nickel dermatitis; nickel dermatitis mainly shows as fash, from the position of frequent contact nickel, and can spread to face, neck even whole body; dermatitis is erythema papule, bubble, is called " nickel sample rash ".The content of nickel element in the alloy that developed countries has limited with human body contacts at present, and develop the high Sn boron alloy of copper base (Cu-Sn-B) of harmful elements such as a kind of not nickeliferous, cadmium, the mechanical performance of this alloy, production and processing performance can substitute fully and surpass Alpaka and packfong, be a kind of have high strength, high resiliency, corrosion-resistant, weldability good, have the feature of environmental protection quality material of colden visual appearance.But when adopting novel copper base boron alloy (Cu-Sn-B) replacement nickel copper-nickel alloy, require the fusing point of employed solder must be below 650 ℃, be preferably between 590～630 ℃, from present Ag base Solders Research situation, the relatively low solder of its brazing temperature has BAg40CuZnCdNi in the Ag base solder, BAg45CuZnCd, BAg50CuZnCd, BAg40CuSnNi, BAg56CuZnSn, Ag30Cu35Zn20In15, Ag64Cu10Zn16Ga10, Ag62Cu10Zn10Ga18 and Ag58Cu30Zn7Ga15, but preceding four kinds of solders contain poisonous element cadmium and nickel, do not meet environmental protection requirement, though then five kinds of solders do not contain poisonous element cadmium and nickel, amount is higher but BAg56CuZnSn contains Ag, other four kinds of solders more contain expensive Ga, elements such as In (contain Ga, the Ag base solder cost of manufacture of In is also higher), therefore price is more expensive, still wish and reducing the content that can reduce noble metal under the situation of fusing point the cost of solder to be reduced greatly in the big civilian industry of consumption.Therefore, develop that warm Ag base brazing material just seems very urgent in the low cost with green environmental protection.

Summary of the invention:

The present invention is exactly at containing poisonous element and the expensive problem of solder in the existing Ag base solder, thereby determine with 30AgCuZn to be initial alloy, content by adjusting copper, zinc also adds the rotten processing element of La that molten element and trace fall in Mn, Sn, P in initial alloy, provide a kind of fusion temperature at 598～615 ℃, temperature contains cadmium Ag base solder and is used for multiple ferrous metal, non-ferrous metal and carbide quartz welding in can substituting, and that does not especially have the soldering of Alpaka frame can be made into middle temperature Ag base solder of filament and weld-ring and preparation method thereof.In warm Ag base solder, it is made up of Ag, Cu, Zn, Mn, Sn, P and seven kinds of components of La, the percentage by weight of the shared solder of each component is respectively: Ag:29.5～30.5%, Zn:31.5～32.5%, Mn:2.5～3.5%, Sn:2.5～3.5%, P:0.4～0.8%, La:0.2～0.4%, surplus are Cu.In the preparation method of warm Ag base solder, its preparation process is followed successively by: select materials, feed intake melting, casting, push and draw the process of dialling, raw materials used is Ag, Cu, Sn-La, Zn, Cu-Mn, Cu-P, its consumption is as the criterion in following scope with the percentage by weight that each raw material in the final products accounts for solder: Ag:29.5～30.5%, Zn:31.5～32.5%, Mn:2.5～3.5%, Sn:2.5～3.5%, P:0.4～0.8%, La:0.2～0.4%, surplus are Cu; The described fusion process that feeds intake is: cathode copper and 1/3 phosphor copper are placed vertically earlier in stove, phosphor copper is clipped in the middle of the cathode copper, temperature is raised to 600～800 ℃ in the stove, be heated rapidly to cathode copper and phosphor copper melts fully, add coverture, stir the remaining 2/3 next phosphor copper of adding again, the stirring of fusing back, add Zn again, add the coverture dewatering borax or forge charcoal,, add the Cu-Mn intermediate alloy after 3～5 minutes, stir, after 1～2 minute, be cooled to 995～1005 ℃, fast white Ag is put in the middle of the liquation below the coverture, add Sn-La at last, be warmed up to 1050～1100 ℃ of stirrings and come out of the stove.Because the fusing point of Sn is low, has only 231.89 ℃, and Sn and other many metals can fuse well.Thereby add Sn can reduce solder fusion temperature, increase wetability, improve liquidity; Can know from the Ag-Sn binary phase diagraml, Sn be joined among the Ag can reduce its fusing point greatly.It is generally acknowledged in Ag copper and add 5%Sn, liquidus temperature can reduce about 25 ℃, but the adding of Sn also will increase the fragility of solder, therefore needs an amount of the adding.In addition, suitable interpolation Sn and the La effect that also has crystal grain thinning.The zinc equivalent that in the element that improves the solder elevated temperature strength, has only Mn be on the occasion of, therefore Mn can play simultaneously improve elevated temperature strength, reduce the solder fusing point, improve wetability, do not worsen solder plasticity, comprehensive function such as secondary deoxidation, but the compatibility of Mn and oxygen is strong, contain the high solder of Mn amount and be not suitable for furnace brazing and gas brazing, so the content of manganese is unsuitable too high in the solder.The P conduct is from the brazing flux element, has good mobility simultaneously, also anti-oxidantly has a better action to what reduce the solder fusing point and improve solder, therefore can on the basis of original Ag base solder, add P in right amount, adjust and form new Ag-Cu-Zn-Sn-P solder system, the key of technology is the fragility problem that how to solve P, but P major part in the soldering fusion process will generate phosphorus pentoxide and be removed with welding slag, have only and be retained on a small quantity in the braze metal, therefore the addition of P is crucial to obtaining excellent joint, needs strict control.The invention has the advantages that: be initial alloy with 30AgCuZn, by in initial alloy, adding the rotten processing element of La that molten element and trace fall in Mn, Sn, P, provide a kind of fusion temperature at 598～615 ℃, the basic solder of the no cadmium Ag of temperature that is used for multiple ferrous metal, non-ferrous metal and carbide quartz welding that its brazing property is can be with containing cadmium Ag base solder suitable.With existing no cadmium Ag base solder BAg56CuZnSn, Ag30Cu35Zn20In15, Ag64Cu10Zn16Ga10, Ag62Cu10Zn10Ga18 compares with Ag58Cu30Zn7Ga15, it is relatively low that it contains the Ag amount, and do not contain expensive Ga, elements such as In (contain Ga, the Ag base solder cost of manufacture of In is also higher), therefore price is relatively low (compares with above-mentioned no cadmium Ag base solder, price has reduced by 50%～150%), thereby can reduce production costs greatly, be existing in the warm nontoxic silver-base solder cost minimum, the silver-base solder that can extensively promote the use of.Simultaneously, in solder manufacturing process, the new material utilization adds deoxidation and the catharsis of micro-P, La, improved the lumber recovery of welding wire and weld-ring widely, compare with the production technology of existing other Ag base solder, the production method of new material has the characteristics of technological process weak point, constant product quality, and extruding and drawing yield rate improve 30%, are beneficial to and apply.

Description of drawings:

Fig. 1 is the influence curve figure of Sn to solder 30AgCuZn fusion temperature, Fig. 2 contains the Sn amount to solder 30AgCuZn spreading area influence curve figure, Fig. 3 is that P is to solder Ag30Cu35Zn32Sn3 fusion temperature influence curve figure, Fig. 4 adds P solder Ag30Cu35Zn32Sn3 to sprawl curve map on no Alpaka and stainless steel, Fig. 5 is that P content is 0.55% Ag30Cu35Zn32Sn3 solder metallurgical structure figure, Fig. 6 is that P content is 0.91% Ag30Cu35Zn32Sn3 solder metallurgical structure figure, Fig. 7 is that P content is 2.01% Ag30Cu35Zn32Sn3 solder metallurgical structure figure, Fig. 8 contains microstructure schematic diagram under the Electronic Speculum of P0.55% solder, Fig. 9 contains microstructure schematic diagram under the Electronic Speculum of P2.01% solder, Figure 10 is the influence curve schematic diagram of Mn to solder Ag30Cu34.4Zn32Sn3P0.6 fusion temperature, Figure 11 is that Mn is to the spreading property curve synoptic diagram of solder Ag30Cu34.4Zn32Sn3P0.6 on the 1Cr18Ni9Ti stainless steel, Figure 12 be Mn to solder Ag30Cu34.4Zn32Sn3P0.6 at 1Cr18Ni9Ti stainless steel braze welding shearing strength of joint curve synoptic diagram, Figure 13 is the Ag30Cu31.4Zn32Mn3Sn3P0.6 solder microstructure schematic diagram that does not contain La, Figure 14 is that La content is 0.3 Ag30Cu31.1Zn32Mn3Sn3P0.6La0.3 solder microstructure schematic diagram, Figure 15 is that La content is 0.5 Ag30Cu30.9Zn32Mn3Sn3P0.6La0.5 solder microstructure schematic diagram, Figure 16 is the Electronic Speculum institutional framework schematic diagram of soldered fitting, and Figure 17 is that the Electronic Speculum of soldered fitting is organized another kind of structural representation.

The specific embodiment:

The specific embodiment one: the middle temperature Ag base solder of present embodiment is made up of Ag, Cu, Zn, Mn, Sn, P and seven kinds of components of La, the percentage by weight of the shared solder of each component is respectively: Ag:29.5～30.5%, Zn:31.5～32.5%, Mn:2.5～3.5%, Sn:2.5～3.5%, P:0.4～0.8%, La:0.2～0.4%, surplus are Cu.

In each method of system of warm Ag base solder, its preparation process is followed successively by: select materials, feed intake melting, casting, push and draw the process of dialling, raw materials used is Ag, Cu, Sn-La, Zn, Cu-Mn, Cu-P, its consumption is as the criterion in following scope with the percentage by weight that each raw material in the final products accounts for solder: Ag:29.5～30.5%, Zn:31.5～32.5%, Mn:2.5～3.5%, Sn:2.5～3.5%, P:0.4～0.8%, La:0.2～0.4%, surplus are Cu.

The specific embodiment two: present embodiment is the preparation method of the no cadmium Ag base of the detailed middle temperature that the applicant did solder, and it in turn includes the following steps:

1, the adding of P element addition manner: P need be passed through intermediate alloy Cu-P, and the weight content of P is 13.5～14% in the Cu-P intermediate alloy that the present invention uses.

2, La element addition manner: rare earth element is an active element, and at high temperature easy oxidation, scaling loss are for smelting process has increased certain degree of difficulty.If directly add rare earth element, rare earth can contact rapidly with oxygen at alloy surface, and by scaling loss, can't enter alloy.But because rare earth has close Sn tendency, after the Sn-La melting is alloy as can be seen according to the Sn-La phasor, the fusing point of Sn-La alloy raises, fusing point as the Sn-La alloy can reach 900 ℃, scaling loss amount in the time of so just can as far as possible reducing the contact alloy surface, so the present invention adopts the mode to add the Sn-La intermediate alloy to add rare earth in solder, reduces the scaling loss amount of rare earth.It is 4.5～5.5% Sn-La intermediate alloy that preparation contains La.The compound method of intermediate alloy is as follows: a. takes by weighing LiCl: KCl=1: 1; B. take by weighing Sn, La, Sn: La=95: 5; C. get Sn and put into rare HCl removal oxide-film; D. salt mixes and to put into crucible, puts in the electric furnace to fusing (effect: secluding air, anti-oxidation); E. put into Sn and trace element successively; F. be incubated 30min, stirred once in per 5 minutes; G. pour out salting liquid, again alloy is poured into porcelain boat.

3, Mn element addition manner: the Mn element is easily oxidation, scaling loss at high temperature, if directly add the Mn element, Mn contacts rapidly with oxygen and by scaling loss, can't enter alloy.Therefore the adding of Mn need be passed through intermediate alloy CuMn, and the weight content of Mn is 35～40% in the CuMn intermediate alloy that the present invention uses.The compound method of CuMn intermediate alloy is as follows: a. packs copper and manganese in the crucible simultaneously, puts copper at the bottom of the crucible earlier, and manganese is put in the centre, adds copper on the manganese again, reserve the copper about 10～15%, treat back temperature adjustment usefulness, material loads, make coverture with dewatering borax or charcoal above, secluding air, anti-oxidation; B. copper all melt back manganese can't fine melt, stir manganese with splash bar and make its quick fusing; C. it is too high that manganese all melts the back temperature, so add remaining about 10～15% bronze medals, alloy temperature dropped to about 980～1000 ℃; D. fusing stirs, and can come out of the stove slagging-off cast then.

4, batching: ingredients principle and step are as follows: (1) is determined the proportioning of the various elements of alloy and is easily consumed the compensation rate of element; (2) under the prerequisite that guarantees alloy mass, the noble metal in the alloy is prepared burden by the lower limit content in the standard as far as possible, to save the consumption of noble metal; (3) batching points for attention: 1. must the adhere rigidly to prescription require (composition, quantity, purity) to stipulate to prepare burden, forbid the way estimated.2. forbid concrete floor, mud ground maybe will with on beat on the object of pollutant, should be placed on the steel plate that cleans up and beat.3. in batching, must eliminate harmful substances such as raw material surface oxide, foreign material, greasy dirt, aqueous vapor.4. the raw material that prepare should divide in special stainless steel (plank box) box that is placed on no-sundries.

5, the selection of coverture: the present invention selects to make coverture with charcoal, because this loose porous active material, can be incubated and can prevent burning, can also clean slag, improve liquidity.Make coverture with charcoal, should handle earlier, charcoal will be done slide, and will do and slip thoroughly, and dried slide can not contain hydrogen, carbon monoxide, methane etc. thoroughly, and this charcoal covers on the alloy liquation, separates out a large amount of gas once heating, and makes the alloy liquation increase gas.It is as follows that charcoal is done the slide method: the charcoal threading is had in the metal drum of venthole, open pore, be placed on and be heated to 780～800 ℃ in the potoven, kept 4～6 hours, then pore is blocked, the holding time should not be grown to cool off stand-by (preferably with using with handling), otherwise charcoal can absorb moisture content once more.Also can use dewatering borax to make coverture.

6, the melting that feeds intake: the rule that feeds intake is, by refractory metal to fusible metal (high-melting-point is to low melting point again), but also should consider the volatilization of metal in high temperature, air-breathing, oxidation and the interaction of metal in fusion process.Reinforced order SnLa always is placed on last adding, and it is former because Sn, La are volatile, and Sn is added in liquation and do not combine with oxygen before the deoxidation and generate oxidation Sn and loose among alloy solution, and this can worsen the processing characteristics (fragility is big) of alloy.Material of the present invention is Ag, Cu, Sn-La, Zn, Cu-Mn, Cu-P, because the inspiratory capacity of Ag is 100 times of volume own, the fusing point of Cu is higher, so release sequence is: cathode copper and 1/3 phosphor copper are placed vertically earlier in stove, phosphor copper is clipped in the middle of the cathode copper, and temperature is raised to 600～800 ℃ in the stove, after being heated rapidly to cathode copper and phosphor copper and melting fully, add coverture, stir and add remaining 2/3 next phosphor copper again, (this 2/3 bronze medal P alloy early is placed on the sole baking and catches up with the moisture on surface), the stirring of fusing back, add Zn again, add the coverture dewatering borax or forge charcoal,, add the Cu-Mn intermediate alloy after 3～5 minutes, stir, after 1～2 minute, be cooled to 995～1005 ℃, fast the white Ag that bakes in the sole is put in the middle of the liquation below the coverture, add Sn-La at last, be warmed up to 1050～1100 ℃ of stirrings and come out of the stove.The item that should note in feeding intake: a, add the trace element material, trace element breaks into fritter (or breaking into thin slice), LMP, volatile trace element should be lowered the temperature, and are rolled in to lift (as rare earth element) among the liquation in the copper sheet fast, and Sn will stir after will adding at last.To accomplish when b, melting that duty stirs, duty is dragged for slag, guarantee the smelting temperature foot, the time foot.When c, melting and the instrument that directly touches of liquation, should be placed on sole or potoven baking back earlier and use.D, various raw material are cleared up surface, the particularly cleaning of copper-phosphorus alloy surface irregularities before feeding intake.

7, casting: will water mold before the casting earlier and be heated to 250～300 ℃, it is too fast to water the too low time cooling of mold temperature, can produce defective, temperature too between senior middle school the metal cooling slow, fast near the cooling of mould metal, cause the composition inequality, and the phenomenon of emerging may occur.Need wait until when alloy cools to 945～955 ℃ and cast again.Alloy liquation funnel will be placed on and water in the middle of the mould pore during casting, and the alloy liquation is filled funnel rapidly, and in casting cycle, alloy liquation funnel remains full, and funnel hole flows out alloy solution, keeps " doing little by little without a break " uninterrupted.The cast alloys liquation is short and thick as far as possible, in order to avoid be involved in air.The sprue cup mouth will remain full state, and the slag that flows into so occasionally in the sprue cup will float on the liquid level, can drag for, and is not brought into mold.

8, extruding: whether extrusion process parameters is selected appropriately whether very important smoothly to the extruded product extruding, particularly relatively poor to the plasticity of material own, processing temperature interval but narrow (machinable maximum plastic range is narrow), very responsive to changes in process parameters, therefore, selecting appropriate extrusion process parameters is the key of decision extruded product quality quality.Squeezing parameter is extrusion temperature, extrusion speed, extrusion ratio, the lubricant type of ingot casting preheat temperature and use etc.Determining of extrusion temperature of the present invention and extrusion speed as table 1, the interior extrusion yield of table 1 scope can reach 99.99%, exceeds extrusion process parameters scope of the present invention, and crackle, fracture of wire etc. will occur, and extrusion yield descends.

Table 1 squeezing parameter

Material	The ingot casting preheat temperature	Temperature retention time (minute)	Matrix preheating time	Extrusion speed	Extrusion ratio
						Ag30CuZnMnSnPLa	?550～580℃	25～35 minutes	30～40 minutes	16～20s	?120±5

9, drawing: 515～525 ℃ of drawing temperature of the present invention, silk pressing amount 15～18%, 475～485 ℃ of annealing temperatures, annealing temperature retention time 25～35 minutes, 380～420 rev/mins of drawing speeds.The yield rate of drawing can reach 99.99% in the above-mentioned drawing process parameter area, exceeds above-mentioned technological parameter, and the drawing yield rate will descend.

The microscopic structure and the performance of the no cadmium Ag base of temperature solder are as follows in the low cost:

Because the fusing point of Sn is low, have only 231.9 ℃, and can well fuse with Ag, copper, therefore in Ag base solder, add the fusion temperature that Sn can significantly reduce solder.Fig. 1 has shown the relation that contains the Sn amount in 30AgCuZn brazing filler metal fusion temperature and the solder.As can be seen from Figure 1, along with the increase of Sn content, the solid-liquid phase line temperature of solder all linearly descends, and the temperature range between the solid-liquid phase line is widened gradually.The situation of sprawling when containing Sn in the Ag base solder on no Alpaka as shown in Figure 2, the result shows that along with the increase of Sn content, the spreading property near linear of solder increases, and increases comparatively fast; About Sn content reaches 10% o'clock its spreading property and nearly doubles.Therefore, contain in the Ag base solder Sn amount between 1-10% the time spreading property of solder good.

It is not obvious that 30AgCuZn does not contain the crystal boundary of solder of Sn, is the αGu Rongti and the eutectic of ingotism, and crystal boundary is many and irregular, and plasticity is fine; The solder crystal boundary that adds Sn2% gets brighter apparent, and ingotism is fuzzy to disappear, and changes granular crystal gradually into, and degree of brittleness increases; When Sn content reached 5-8%, crystal grain was obviously thick, and crystal boundary is bright to be presented, and solder obviously becomes fragile.Therefore, in order to guarantee the plasticity and toughness of solder, contain the Sn amount and should not surpass 5%, the present invention gets and contains the Sn amount between 2.5～3.5%.

P has the effect of further reduction Ag base solder fusion temperature, the solder fusion temperature that adds P changes as shown in Figure 3, the fusion temperature of solder Ag30Cu35Zn32Sn3 is 665 ℃～755 ℃, the solidus temperature of solder is reduced to about 607 ℃ behind the P of adding 0.34%, liquidus temperature is reduced to about 650 ℃, the solidus temperature of solder is reduced to about 606 ℃ behind the P of adding 0.58%, liquidus temperature more is reduced to about 620 ℃, along with the increase of P content, the temperature range between the liquid-solid phase line narrows down gradually.Add P as shown in Figure 4 to the spreading property influence of solder Ag30Cu35Zn32Sn3 on no Alpaka and stainless steel, as can be seen from the figure, increase along with P content, the spreading property of solder on no Alpaka and stainless steel all will reduce, therefore the addition of P needs strict control, guaranteeing under the alap situation of fusion temperature that the addition of P should not surpass 1.12%.

Its institutional framework such as Fig. 5, Fig. 6, shown in Figure 7 behind the Ag30Cu35Zn32Sn3 adding P, when P content was 0.55%, as Fig. 5, solder organized crystal grain tiny, and in fine and closely woven little crystal grain, crystal grain does not have directionality, and crystal boundary is many, and material has plasticity preferably; When P content was increased to 0.91%, as shown in Figure 6, the dendroid solid solution and the eutectic of solder faded away, and crystal boundary is fuzzy, had rich P-compound tissue to form, and at this moment, the fragility of solder increases to some extent; When P content reached 2.01%, as shown in Figure 7, the solder grain coarsening was big, and crystal boundary is obvious, and the fragility of solder increases.Table 2 is the Electronic Speculum microscopic structure and the EDAX results of solder, and with reference to Fig. 8, Fig. 9, therefrom as can be seen, A for being the tissue of matrix with copper, is grouped into according to its one-tenth mutually, and it is for containing P, the bronze tissue of Ag as can be seen; B is an eutectic structure, and for containing the higher Ag based solid solution of Zn amount, ash is the copper based solid solution to white mutually mutually, and biphase equilibrium distributes, and forms the two-phase eutectic structure, and this tissue helps the raising of plasticity; C is for being the tissue of matrix with Ag, and its fusing point is lower, and what have gathers into big bulk partially, and great majority are to be distributed in the crystal boundary edge; P mainly concentrates on the D phase, is the black particle shape, and disperse is in the solder tissue.P combines with Cu in this tissue and forms Cu ₃The P intermetallic compound.Cu ₃P fusing point height (1022 ℃) is at first separated out in the time of crystallization, surrounds low-melting solid solution on every side, finds out that from microscopic structure this organizing presents furvous in the drawings.In sum, for fusion temperature, spreading property and the plasticity and toughness that guarantee solder can both satisfy manufacturing requirements, P content should not surpass 0.9% in the Ag30Cu35Zn32Sn3 solder, and the present invention gets P content between 0.4～0.8%.

The energy spectrum analysis of table 2 solder (percentage by weight)

Composition	Material	????Ag	????Cu	????Zn	????Sn	????P
							????A	????1	????16.83	????62.88	????14.16	????-	????6.13
????2	????12.55	????57.74	????24.95		????2.85
						????B		????1	????28.30	????34.69	????34.89	????2.12	????-
????2	????28.95	????34.68	????34.14	????2.23
							????C	????1	????58.74	????10.88	????28.04	????2.35	????-
????2	????54.97	????22.98	????15.78	????6.16	????0.11
						????D			????-	????57.74	????32.87	????-	????9.40
????2	????-	????44.53	????42.53	????-	????12.94

The solid solubility of Mn in Ag, Cu is bigger, so the plasticity of Ag-Cu-Zn-Sn-Mn-P solder is also better behind the adding Mn.The Zn equivalent of Mn is 0.5, adjusts the ratio of Mn, Cu, can adjust solder melting region and soldering processes performance.But the compatibility of Mn and oxygen is strong, when containing Mn amount in the solder and be higher than 4%, will cause a large amount of scaling loss of Mn during soldering, and furnace brazing and gas brazing therefore will no longer suit.In order to guarantee the popularity of solder using method of the present invention, so the content of manganese will be limited in below 4% in the solder.The solder fusion temperature that reduces the ratio of Cu and add Mn changes as shown in figure 10, and the fusion temperature of solder Ag30Cu34.4Zn32Sn3P0.6 is 606 ℃～620 ℃, adds behind 3.0% the Mn fusion temperature of solder and reduces to 598 ℃～615 ℃.And after the adding along with the Mn alloying element, the bonding strength height and the soldering processes performance of joint all increase, and especially the good wetability to carbide makes this class solder can obtain good application in carbide quartz welding.Add Mn to the spreading property of solder Ag30Cu34.4Zn32Sn3P0.6 on the 1Cr18Ni9Ti stainless steel and influence such as Figure 11, shown in Figure 12 of soldered fitting shear strength, as can be seen from the figure, along with the increase of Mn content, solder on the 1Cr18Ni9Ti stainless steel spreading property and the shear strength of soldered fitting all increase.Therefore, the present invention gets and contains the Mn amount between 2.5～3.5%.

Figure 13 is the Ag30Cu31.4Zn32Mn3Sn3P0.6 solder microstructure schematic diagram that does not contain La, Figure 14, Figure 15 are that the solder microscopic structure of Ag30Cu31.4Zn32Mn3Sn3P0.6 changes schematic diagram behind the adding La, can find out significantly that from figure the adding of rare-earth elements La played the effect of refinement to the solder tissue, and when adding 0.3wt%La, refining effect is very remarkable, and the average-size of crystal grain is reduced to 1 μ m～2 μ m from 4 μ m～5 μ m.But along with the further increase of content of rare earth, particularly when content of rare earth had surpassed 0.5wt%, tissue became inhomogeneous, even can cause the segregation of composition.Therefore, the present invention gets and contains the La amount between 0.2～0.4%.

The specific embodiment three: present embodiment is the preparation process that soldering does not have Alpaka (Cu-Sn-B alloy) frame.

Brazing process and technological specification:

1, the surface treatment of test specimen: owing to exist oxide-film and adsorption layer on the test specimen surface, and these adsorption layers tend to influence the brazing quality of joint, therefore will carry out necessary striping before weldering handles, the striping method that is adopted is a manual machinery striping method, promptly use 240#-1000# waterproof abrasive paper to the test specimen surface grinding, again with acetone and absolute ethyl alcohol flushing.2, the selection of mode of heating: it is fast that high-frequency induction brazing has firing rate, temperature is grasped easily, good work environment, heating schedule is realized control automatically easily, the qualification rate advantages of higher of product, therefore be applied to the large-scale industry soldering and produce, can reduce production costs greatly, enhance productivity.The present invention adopts high-frequency induction brazing not have the soldering of Alpaka frame for this reason.3, welding: at first adopt overlapping mode that test specimen is reasonably assembled, test specimen and careful being placed on the smooth graphite flake of solder (Ag30Cu31.1Zn32Mn3Sn3P0.6La0.3) that cleaning is good, attention prevents the misalignment of test specimen.In order to make the test specimen contact good, under high-frequency heating, do not rotate, on test specimen, add weight.The setting output power of power supply is 10KW, 25～28 seconds heat time heating times, the heating back time of staying 3～5s.

The result:

The interface microscopic structure of soldered fitting shows that brazed seam mainly is divided into three districts as Figure 16, shown in Figure 17, i.e. the interfacial reaction district of Cu mother metal and solder, the brazed seam matrix area of the coarse grain zone of close reaction zone and centre.Wherein A is greyish white form and aspect mutually, is rich in Ag, and these mutually most strips are distributed in around the Cu based solid solution; B is based on Cu, its content reaches more than 60%, next is Zn, content can reach about 30%, because forming the solubility of solid solution between Cu, the Zn is about about 40%, thereby whole Zn and Cu form solid solution, avoided the generation chance of Ag-Zn frangible compounds, and this helps the raising of strength of joint mutually; C is eutectic structure mutually, mainly is to contain Zn, and Ag measures more Cu based solid solution and contains Cu, the eutectic structure that the more Ag based solid solution of Zn amount is formed; For containing the P phase, this is Cu to D mutually, Zn solid solution and Cu mutually ₃P is because Cu ₃P is a brittle substance, so the distribution of phase is bigger to the fragility influence of solder.Because P is a volatile element, scaling loss in the process that brazing temperature raises causes the content of P in the soldered fitting to reduce, and the reduction of P content makes frangible compounds Cu ₃P reduces, and this is favourable to the performance that improves soldered fitting.When adopting solder brazing of the present invention not have Alpaka, soldered fitting shearing test complete rupture is on mother metal.Its maximum stress was about 220.9MPa when shearing test recorded fracture, and the fracture nidus is on the annealing weak area of copper base metal.

In sum, when adopting solder brazing of the present invention not have Alpaka, the joint of soldering is very firm, can satisfy the instructions for use of frame fully.

Claims (8)

1. warm Ag base solder in a kind, it is characterized in that it is made up of Ag, Cu, Zn, Mn, Sn, P and seven kinds of components of La, the percentage by weight of the shared solder of each component is respectively: Ag:29.5～30.5%, Zn:31.5～32.5%, Mn:2.5～3.5%, Sn:2.5～3.5%, P:0.4～0.8%, La:0.2～0.4%, surplus are Cu.

2. the preparation method of warm Ag base solder in a kind, its preparation process is followed successively by: select materials, feed intake melting, casting, push and draw the process of dialling, it is characterized in that: raw materials used is Ag, Cu, Sn-La, Zn, Cu-Mn, Cu-P, its consumption is as the criterion in following scope with the percentage by weight that each raw material in the final products accounts for solder: Ag:29.5～30.5%, Zn:31.5～32.5%, Mn:2.5～3.5%, Sn:2.5～3.5%, P:0.4～0.8%, La:0.2～0.4%, surplus are Cu; The described fusion process that feeds intake is: cathode copper and 1/3 phosphor copper are placed vertically earlier in stove, phosphor copper is clipped in the middle of the cathode copper, temperature is raised to 600～800 ℃ in the stove, be heated rapidly to cathode copper and phosphor copper melts fully, add coverture, stir the remaining 2/3 next phosphor copper of adding again, the stirring of fusing back, add Zn again, add the coverture dewatering borax or forge charcoal,, add the Cu-Mn intermediate alloy after 3～5 minutes, stir, after 1～2 minute, be cooled to 995～1005 ℃, fast white Ag is put in the middle of the liquation below the coverture, add Sn-La at last, be warmed up to 1050～1100 ℃ of stirrings and come out of the stove.

3. the preparation method of warm Ag base solder in a kind of according to claim 2 is characterized in that casting cycle is as follows: when treating that alloy temperature after the melting drops to 945～955 ℃, it is cast in 250～300 ℃ water in the mold get final product.

4. the preparation method of warm Ag base solder in a kind of according to claim 2, needing in the extrusion process to it is characterized in that the technological parameter controlled as follows: ingot casting preheat temperature: 550～580 ℃, temperature retention time: 25～35 minutes, matrix preheating time: 30～40 minutes, extrusion speed: 16～20s, extrusion ratio: 120 ± 5.

5. the preparation method of warm Ag base solder in a kind of according to claim 2, it is characterized in that drawing and need the technological parameter controlled as follows in the process of dialling: drawing temperature: 515～525 ℃, silk pressing amount: 15～18%, annealing temperature: 475～485 ℃, the annealing temperature retention time: 25～35 minutes, drawing speed: 380～420 rev/mins.

6. according to claim 2,3, the 4 or 5 described preparation methods of warm Ag base solder in a kind of, the content that it is characterized in that P in the selected Cu-P intermediate alloy is 13.5～14% of Cu-P weight alloy.

7. according to claim 2,3, the 4 or 5 described preparation methods of warm Ag base solder in a kind of, the content that it is characterized in that La in the Sn-La alloy is 4.5～5.5% of Sn-La weight alloy; The compound method of Sn-La alloy is as follows: a. takes by weighing LiCl: KCl=1 by weight: 1; B. take by weighing Sn, La, by weight Sn: La=95: 5; C. get Sn and put into rare HCl removal oxide-film; D. crucible is put in the salt mixing, puts in the electric furnace to fusing; E. put into Sn and La successively; F. be incubated 30min, stirred once in per 5 minutes; G. pour out salting liquid, again alloy is poured into porcelain boat and get final product.

8. according to claim 2,3, the 4 or 5 described preparation methods of warm Ag base solder in a kind of, it is characterized in that in the Cu-Mn alloy that the content of Mn is 35～40% of Cu-Mn weight alloy; The compound method of Cu-Mn alloy is as follows: a. packs the copper of manganese and 85～90% in the crucible simultaneously, puts copper at the bottom of the crucible earlier, and manganese is put in the centre, adds copper on the manganese again, makes coverture with dewatering borax or charcoal above; B. copper all melt back manganese can't fine melt, stir manganese with splash bar and make its quick fusing; C. it is too high that manganese all melts the back temperature, so add 10～15% remaining bronze medals, makes alloy temperature drop to 980～1000 ℃; D. fusing stirs, and can come out of the stove slagging-off cast then.

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