Interface of connect of drill rod solder ruptures mechanical experiment research

So The Reference Basis Is Provided For Evaluation Of Fracture Performance Of Brazed Joint Interface.

Keywords: The area of interface of connect of drill rod solder of material of 　 of Release Rate Of Strain Energy of 　 of Interface Fracture of Brazed Joint 　 is by brazed seam and draw near mother capable person comprises have material property the local intermediate zone of discontinuous feature, this area arises possibly below working environment multiform injury and rupture, because this studies interface of connect of solder of material drill rod,rupture function has important sense to raising the dependability of component of drill rod solder. Interface of connect of solder of material drill rod ruptures craft of solder of the function matched stack of behavior and brazed seam and mother capable person, drill rod, outside carry a variety of elements such as the form to concern, have not establish contact of solder of concerned drill rod at present rupture analytic method. Had developed the interface that rise to rupture mechanical theory solders to drill rod of the head rupture the analysis has real sense, its basically study content is rupture the interface mechanical method applies at connect of drill rod solder rupture function assess. 1 interface ruptures analysis of crackle of analytic method interface is the interface ruptures mechanical main research content [1] , as a result of the interface the stretch property of two side material differs, material is mechanical of function break deserve to make interfacial crackle is unsymmetrical substantially compound model crackle problem (namely pure Ⅰ be together with pure Ⅱ coupling) . Before rupture, crackle is most advanced at the same time action has law Xiangzheng stress to mix tangential shearing stress, have already on crackle face stretch displacement to have again slip displacement, include consequently stretch model and slip model stress intensity factor, factor of its stress intensity is answer stress intensity factor, namely K=K Ⅰ + IK Ⅱ , but answer stress intensity factor does not have clear mechanical sense [1] . Consider to make clear, of interfacial crackle rupture the function GC that tenacity is phase angle ψ (ψ ) , among them: ψ =tg-1(K Ⅱ / K Ⅰ ) (the mixture of 1) 　 interface ruptures the condition is: G(ψ ) ≥ GC(ψ ) (in 2) type, g can be released for interfacial crackle meet an emergency rate. Research makes clear, to actual application, use interfacial crackle meet an emergency to be able to be released lead those who regard a description as the interface to rupture tenacity parameter is relatively convenient [2 ～ 4] . The article accepts a particular case in the light of the drill rod solder of material, designed curved Sandwich at 4 o'clock model the interface ruptures mechanical test specimen (graph 1) , this type test specimen can make sure area of interface of edge of the crackle in experiment process is patulous, and test specimen won't be broken suddenly firm, in addition, test specimen appearance is simple, treatment is convenient. Graph 1 curved Fig of test specimen of to load Sandwich at 4 o'clock.

The interfacial crackle meet an emergency of this kinds of test specimen can release 　 of 1 　 Sandwich Sample Of Four_point Bend Loading rate can press type calculates [5 ～ 6] : (3) among them (planar stress) or (planar meet an emergency) in type, e1, e2 and ν 1, the 2 stretch model quantities that are brazed seam interlining and mother capable person respectively and Poisson compare ν ; B, l is the width of test specimen and span of inside and outside respectively; PC is critical load; λ 2 be opposite for photograph of underside mother capable person the equivalent length at interlining; IC is interfacial crackle cross section of length of unit of the following part is neuter to its inertial quadrature of the axis; I is not cross section of length of craze part unit is neuter to its equivalent and inertial quadrature of the axis. By go up type is knowable, use Sandwich test specimen to determine critical meet an emergency can release crackle of interface of connect of drill rod solder leading is to decide test specimen to be opened in the crackle in to load process actually crack a dot. Crackle opens the load of correspondence of the place that crack a dot to be critical load, according to critical load through type (3) can be calculated critical meet an emergency can release interfacial crackle rate. 2 tests data and method experiment originally place is GH4033 of high temperature alloy with mother capable person, the Ag-Cu that drill rod makings forms for 72% Ag and 28% Cu in all brilliant organizes drill rod material. GH4033 measures E to be 215 GPa in the stretch model below room temperature, cut a model to measure μ to be 84 GPa, poisson is than ν 0.

28. Take two kinds of test specimen (graph 2) , its feature dimension is respectively: (1)L0=70 Mm, b=12.

5 Mm, h1=4 Mm, h2=5 Mm, h=0.

2 Mm and H=0.

5 Mm; (2)L0=80 Mm, b=12.

5 Mm, h1=5 Mm, h2=5 Mm, h=0.

2 Mm and H=0.

5 Mm. Graph Fig of dimension of 2 　 Sandwich test specimen.

Preparation of test specimen of 　 of 2 　 Sandwich Sample Dimension lacks shape of degree of lip-rounding two kinds (graph 3) , cut width is 0.

12 Mm. (A) has transverse gap (B) pursues without transverse breach Fig of breach of 3 　 Sandwich test specimen.

System of test of 　 of 3 　 Notch Of Sandwich Sample basically includes to load, test and record 3 parts (graph 4) . The span on to load part is adjustable limits is 40 ～ 120 Mm, next span are adjustable limits is 24 ～ 84 Mm. Test specimen of this to load system is consequently applicable size scope is bigger, and be opposite neuter is better, carrying capacity is stronger, can assure the precision of the experiment and accuracy. The experiment uses BLR-1 pillar to pull respectively press bridge of sensor and YZJ-1040 double cantilever to place type P of carry on one's shoulder of the to load outside amplify plan test and crackle stretch displacement V. After appearance of meet an emergency of YD-15 of sampling signal classics dynamic resistor magnifies, through X-Y function recorder draw gives P-V curve. Graph Fig of 4 tests system.

　 of 4 　 Test System pursues the 5 P-V curves that are a model, test result makes clear, interface of adoption connect of drill rod solder ruptures mechanical experiment can mirror those who give test specimen to rupture feature and the load volume that craze burns. Make clear on P-V curve show gave correspondence at interfacial crackle critical meet an emergency can release the critical load value of rate, in test specimen the circumstance of the craze when two side are different falls, the curve recorded two side to part of craze the first choose the place with the 2nd dart, mirrorred interface of connect of drill rod solder accurately to rupture thereby behavior. Go up according to P-V curve " dart is nodded " the load of place and displacement value, according to type (3) can be calculated critical crackle meet an emergency can release an interface of connect of solder of GH4033/Ag-Cu/GH4033 drill rod rate, namely interfacial fracture toughness. (A)(b) pursues Fig of curve of 5 　 P-V.

Analysis of result of 5 　 P-V Curve3 and discuss to rupture through interface of connect of drill rod solder the experiment can observe interfacial crackle basically has 3 kinds when the graph shows 6 times to diffuse form. The intensity that the intensity of capable person of test specimen mother and tenacity expect than Ag-Cu alloy drill steel and tenacity are a lot of taller, the inhomogenous sex of mechanical function matched stack brings about contact the fragile division that the interface makes contact of solder of whole drill rod, once crackle happens in interfacial area, can expand along interfacial area 6(a) seeing a picture. As interfacial crackle patulous the accretion that reachs test specimen flexibility, become especially crackle is most advanced be close to gradually inside when fulcrum, test specimen curves deflection great, as a result of interfacial crackle right now most advanced condition getting power produces change, load phase angle changes a symbol ceaselessly, bring about crackle fluctuant between fluctuation interface patulous 6(b) seeing a picture. If drill rod expects,in process of drill rod solder fusion is compared even, form the interface with stronger adhesion strength, crackle general choice expands in the crackle in brazed seam obstruction expands on lesser method 6(c) seeing a picture. Rupture according to the interface mechanical theory, influence interface crackle expands the main factor of method has form of material combination, load, interface to rupture tenacity. Among them the function combination of drill rod makings and mother capable person affects crackle directly behavior of meet an emergency of most advanced stress, what bring about interfacial crackle possibly is mutual and built-in, show complex flaw patulous contrail. Graph the patulous form Fig of 6 interfaces crackle.

Makings of drill rod of 　 of 6 　 Extension Of Interface Crack and function of mother capable person combine pair of its interface divisions fight rupture function also has bigger effect, the drill rod when the reason depends on contact forming expects to mother capable person permeate and diffuse, the transition with the discontinuous function that is different from mother capable person and composition of drill rod material was formed between brazed seam and mother capable person interfacial layer. Drill rod makings and collocation of mother ability part are reasonable, the intensity of interfacial layer and model tenacity can rise somewhat, the intensity that expects high even at mother capable person and drill rod and model tenacity, improve interfacial joint thereby rupture tenacity; If composition is broken,match, the intensity of contact and model tenacity drop, the crackle of contact expands resistance is reduced, rupture with respect to what can reduce contact tenacity. Meet an emergency of critical to the interface crackle can release ply of brazed seam layer the effect of rate is relatively mixed, with material combination and craft of drill rod solder have bigger concern. If can release rate computation formula to look from interfacial crackle meet an emergency only, increase as brazed seam ply, meet an emergency can be released rate after increasing some peak value, begin to drop. After brazed seam ply exceeds certain range, type (3) can produce bigger error, need uses more accurate calculation method further, length of be confined to, here introduces in detail no longer. The interfacial connection force of brazed seam of connect of drill rod solder and mother capable person is fought to the interface rupture function and rupture behavior has bigger effect, be like formation contact interface function good, join force is powerful, and nonexistent stoma, slag inclusion, not solder shows etc defect, force of powerful interfacial connection will make the interface is obtained fight high rupture ability, with preventing crackle patulous, the interface that improves joint thereby ruptures tenacity; Conversely, the interface that weakens contact ruptures tenacity. Critical crackle meet an emergency can be released leading is area of interface of connect of solder of assess drill rod ruptures the main index of tenacity, to component of drill rod solder rupture analysis and quality of drill rod solder assure to have important sense. Interface of connect of solder of material drill rod ruptures the foundation that mechanical research is analysis of integrality of structure of drill rod solder, the test that this institute completes receives head interface area to drill rod solder fight rupture function assess is feasible, obtains experiment curve can decide crackle of interface of connect of drill rod solder opens interfacial critical condition, also can rupture to its interface the patulous behavior of the crackle in the process undertakes an analysis, its study interface of connect of solder of eventuate drill rod ruptures the analysis provided referenced basis. CNC Milling CNC Machining