Organization of extruding of fuse-element of autogenous TiC_p/2024 composite material and mechanical function

2% , rupture the form ruptures for tenacity, can think composite material of autogenous TiCp /2024 has good integrated and mechanical performance from this. Composite material of TiCp of keyword fuse-element extruding organizes Zhou Bide(Harbin Institute Of Technology of 　 of Yang Bo of 　 of Zhang Erlin of 　 of Zeng Songyan of 　 of mechanical function Microstructure And Mechanical Properties Of Liquid-extruded In-situ TiCp/2024 CompositesMa Mingzhen, wu Jiejun of 　 of Yuan Guangjiang of 　 of Gui Manchang of Harbin)Wang Dianbin 　 (Institute Of Aeronautical Materials, beijing) 　 　 [Abstract] S) of  of B of  of σ of 　 The Ultimate Tensile Strength(, σ , δ of Elastic Modules(E) And Elongation () Of The In-situ TiCp/2024 Composites Was Tested At The Heat Treatment Condition Of T4 And T6.

The Microstructure Of The In-situ Extruded TiCp/2024 Composites Was Observed By The Use Of SEM, and The Fracture Morphology Was Also Observed.

The Results Show That The Ultimate Tensile Strength And The Elastic Modules Of The Composite With 15wt%TiCp Are 540MPa, 430MPa And 92GPa Respectively, and The Elongation Is Up To 3.

2% .

The Fracture Is Ductile.

All Of These Indicte That The Composites Are Of Good Mechanical Properties. Metal of 　 of Mechanical Properties of 　 of Microstructure of 　 of Composite of 　 of TiCp of 　 of Keywords 　 Liquid Extrusion base composite material has Gao Bijiang to spend, it is good to compare modular quantity, heat-resisting, wear-resisting, fatigue resistance high wait for good character, already made one of material that etc of aviation, spaceflight, auto industry provides attraction extremely in new and high industry [1 ～ 5] . Grain increases model metallic radical the research of composite material, from 70 time later period arisen, got swift and violent development nearly a few years, react among them synthesis former autogenous grain increases model metallic radical composite material with its preparation craft is simple, quality of complex reaction product is high, can avoid the advantage such as the reaction of adscititious grain and interface and the pollution that bring subsequently effectively, and the times attention that gets material science worker. This research uses reaction to synthesize craft preparation out to give birth to TiCp/2024 grain to increase model metallic radical composite material, to its the mechanical function of microstructure and system of different heat treatment undertook study, undertook fuse-element extruding experiments, with period the stoma in decrease effectively or removing composite material, make organize function to get clear improvement. This experiment uses 1 experiment method 1000kN 4 column are all-purpose hydraulic press undertakes to autogenous TiCp/2024 composite material fuse-element squashs, extrusion ratio is 12.

5 ∶ 1, the sectional dimension of extruding wool preform is 20mm × 10mm, respectively edge extruding direction (fore-and-aft and sectional) with perpendicular extruding direction (transverse and sectional) take constituent sample, undertake through SEM microstructure observes, use T4 and T6 system of two kinds of heat treatment, with Instron machine of all-purpose material experiment checked the mechanical performance of TiCp/2024 composite material, drawing speed is 0.

008mm/s. 2 tests result and analysis 2.

The extruding of composite material of 1 　 TiCp/2024 organizes a scheme 1 it is TiCp/2024 composite material extruding board preform is fore-and-aft and sectional organize with transverse and sectional SEM. Fiber strip is shown to distributing in fore-and-aft and sectional TiCp, if pursue,1(a) place is shown. In transverse and sectional SEM organization, of TiCp distributing evener, distributinging configuration of nonexistent fiber strip, be like graph 1(d)(e)(f) . Observation returns discovery, as the addition of content of TiCp weight percentage, the trend that shows fiber strip to distributing in fore-and-aft and sectional TiCp is reduced, if pursue,1(c) place is shown. The analysis thinks: In fore-and-aft and sectional on TiCp shows fiber strip to distributing, its reason may be when the content when TiCp is low, the viscosity of material is low, liquidity is good, it is consequently in follow-up extruding process, tiCp is out of shape along with the flow of matrix alloy and in extruding direction (fore-and-aft and sectional) form fiber strip distributing, and increase ceaselessly when TiCp content and when dispersion of distributinging all the more, bring about metallic fluid viscosity to increase, when the metal flows, between metallic fluid and TiCp or the attrition obstruction between TiCp and TiCp increases, mutual block up, make TiCp also is reduced along with the mobile trend when metallic flow is out of shape, reason its distributing even. Graph the fuse-element extruding of composite material of 1 　 TiCp/2024 is organized (A) , (B) , (The extruding with fore-and-aft and sectional C) is organized; (D) , (E) , (F) , transverse and sectional extruding is organized (A, d)5wt%TiCp; (B, e)10wt% TiCp; (C, f)20wt% TiCp Fig.

1 　 Microstructrue Of TiCp/2024 Composites For (a, b, c) Longitudinal And (d, e, f) Transverse Section (a, b)5wt%TiCp; (C, d)10wt%TiCp; (E, f)20wt% TiCp 2.

Extruding force of fuse-element of composite material of 2 　 TiCp/2024 learns function 2.

2.

The feature that the matrix of composite material of heat treatment craft of composite material of 1 　 TiCp/2024 organizes is having huge effect to the mechanical function of material, and the constituent structure of matrix often is the decision of place of heat treatment craft that chooses by place, because this chooses sound heat treatment technology,having crucial effect to improving the mechanical performance of composite material. According to the data [6] introduce, the affiliation of grain photograph is lesser to influence of composite material solution treatment, solid dissolve temperature still maintains the solid dissolve temperature of former matrix, but can shorten solid dissolve time, have bigger effect to the behavior of effectiveness for a given period of time of composite material, because this is necessary,have initial choice to the heat treatment craft of composite material and means of effectiveness for a given period of time. Temperature of this experimental solution treatment is in certainly (℃ of 495 ± 5) , heat preservation time is 1.

5h, use T4 and T6 system of two kinds of heat treatment. Graph 2 it is different TiCp content when, composite material hardness is worth the change that follows time of effectiveness for a given period of time. See by the graph, the time of peak effectiveness for a given period of time of 2024 matrix is 8h, after time of effectiveness for a given period of time exceeds 8h, will appear to pass act of effectiveness for a given period of time apparently, hardness value begins to drop and the time of peak effectiveness for a given period of time of TiCp/2024 composite material is centered in 4 ～ 5h, increase to shorten somewhat along with TiCp content, the hardness of the material after peak of effectiveness for a given period of time passes is worth and did not reduce apparently, individual still rise somewhat, can think from this, the behavior of effectiveness for a given period of time of composite material relatively matrix shifts to an earlier date. Graph the change that value of hardness of composite material of 2 　 TiCp/2024 follows time of effectiveness for a given period of time (T6)Fig.

2 　 The Change Of Microhardenss Of TiCp/2024composites With Artificial Ageing Time(T6)2.

2.

The mechanical function 　 of composite material of 2 　 TiCp/2024 expresses the 1 mechanical function that is TiCp/2024 composite material. See by next watches, when 15wt% of TiCp content ≤ , s of the σ B of material of TiCp/2024 composite material, σ , E rises along with the addition of TiCp content, δ is reduced along with the addition of TiCp content. Below T4 condition, when TiCp content is 15wt% , σ B, reach maximum with σ S, it is 476MPa and 387MPa respectively, add up to metallographic to compare with matrix, rise respectively 30% with 59% , rise than intensity 22% (TiCp/2024 density makes an appointment with 285g/cm3) . Add when TiCp content to 20wt% when, σ B and σ S all drop somewhat, but range is not big. Compare with T4 condition photograph, the σ B below T6 condition and σ S all have bigger rise, when TiCp content is 15wt% , σ B and σ S are 540MPa and 430MPa respectively, add when TiCp content to 20wt% when, the fall of intensity extent is slower, but outspread rate falls apparently, δ is 3.

2% . Stretch model measures E to show linear to rise along with the addition of TiCp content, the effect that gets heat treatment is lesser, when content TiCp is 20wt% , e is as high as 92.

5GPa, relatively base material rises 29.

3% . By afore-mentioned analysises knowable, s of the σ B of composite material, σ and E rise along with the addition of TiCp content, δ drops along with the addition of TiCp content apparently, but when TiCp content is 20wt% , the δ lowest value of the composite material that handles via T4 is 4.

7% , the δ lowest value of the composite material that handles via T6 is 3.

2% , right now it is thus clear that autogenous TiCp/2024 composite material still has better plasticity. The T4 of 　 of 　 Mechanical Properties Of TiCp/2024 Composites<DIV Align=center> of Table of mechanical performance list of TiCp/2024 composite material handles T6 to handle δ of S/MPa of σ B/MPa σ / δ of S/MPa of σ of %E/GPa σ B/MPa / %E/GPa2024 alloy 36521516.

47042527212.

3705wt%TiCp/202442532011.

877.

551035210.

27710wt%TiCp/20244603409.

6835354008.

983.

515wt%TiCp/20244763876875404305.

28820wt%TiCp/20244503554.

7925374283.

292</DIV>2.

The fracture surface of composite material of 3 　 TiCp/2024 analyses a scheme the appearance of 3 fracture surface form that issue TiCp/2024 composite material for SEM, see by the graph, nest of many pliable but strong exists on fracture surface, show collect of small Kong Ju tenacity to rupture apparently, have on predestined relationship of the side outside nest of pliable but strong tear off slippage mark apparently, see in nest of pliable but strong bottom has a lot of petty grain OK and clearly, through can the nest of pliable but strong to having grain has music composition analysis, without the existence of Ti element, did not discover those who have facet feature to rupture on whole fracture surface additionally area, namely of nonexistent grain rupture, the specification is here " pull out " model rupture, its reason is the plasticity that arises by matrix slippage is out of shape and grain and matrix combine what the interface is in to take off stick cause.

Additionally observation returns discovery, the size of the nest of pliable but strong of composite material fracture surface that TiCp content is 5wt%(a) is large and the amount is little, its brim is shown apparently spin form, the size of the nest of pliable but strong of composite material fracture surface that TiCp content is 15wt%(c) is small and the amount is much, submit form waiting for an axis. This shows, along with the addition of TiCp content, composite material fracture surface by tear off nest of spun pliable but strong the form of nest of axial pliable but strong such as graduate, appearance of nest of pliable but strong by arrive greatly small, amount by arrive less much, the plasticity that makes clear material drops gradually, and nest of pliable but strong is more by grain " pull out " and form, the main reason that rupture is what grain and matrix combine an interface to take off stick be caused by. Its form mechanism to be: TICp or other field trash fall in outside force action, cannot undertake is out of shape continuously along with matrix, herein produces a bad stuff to accumulate, produce stress concentration, these particle and matrix union interface are broken away from form small hole, increase as stress, small hole is brought up ceaselessly, mutual annex, the crackle that makes small hole is formed expands further bring about material to shrink neck and rupture. Graph the Fig of appearance of fracture surface form of composite material of 3 　 TiCp/2024.

3 　 The Fracture Morphology Of TiCp/2024 Composites(a) 5wt%TiCp; (B) 10wt%TiCp; (C) 15wt%TiCp3 conclusion (the organization of TiCp/2024 composite material after 1) squashs to fuse-element through SEM undertook observation and analysis, in the material that discovers TiCp content is inferior, fore-and-aft and sectional TiCp has the tendency that fiber shape distributings, along with the addition of TiCp content this kind of trend disappears gradually, and in transverse and sectional TiCp distributing even. (2) analysed T4 and T6 the relation of the mechanical function of the material below two kinds of condition and TiCp content, outside be being reduced along with the addition of TiCp content except plasticity, σ and E rise apparently, especially TiCp content has maximum for the mechanical function of the composite material of 15wt% , s of σ B, σ , E achieves 540MPa, 430MPa and 92GPa respectively, as bigger than having as matrix alloy photograph rise. (3) analysed the feature of fracture surface of TiCp/2024 composite material, point out rupture the form ruptures for tenacity, its reason basically is form small hole for core with TiCp, then is patulous, make the interface of TiCp and matrix is taken off stick cause. CNC Milling CNC Machining