Crystal organization is controlled the deposit of growth CVD alumina coating, microstructure and character (go up)

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The article studied nucleus forms the influence of pair of CVD Al2O3 microstructure and coating function. The experiment presses deposit of the following requirement respectively with AAl2O3 coating: ① did not use nucleate control; ② uses nucleate to control and obtained those who make clear (102) , (104) and (100) grows crystal organization. The character that uses lens of report of X ray diffraction, scanning and transmission report lens to use coating to the experiment undertook an analysis; Controlled to crystal organization growth coating undertook assessment in the wearability in turning experiment. The chemistry of nucleate surface is characteristic to beforehand the photograph structure of set CVDaAl2O3 coating and grow crystal organization appears crucial. Through optimizing nucleate measure, improved the wearability of coating apparently, and ground of model of coating of these a few kinds of CVDa-Al2O3 by relatively lesser, comprise without hole, flawless grain. (104) organized A-Al2O3 coating of the structure to show first-rate wearability. Industry of cutting of metal of 1 foreword setting shows a skill definitely the characteristic of fast development, the market competition that this is economic globalization, ceaseless aggravate, power is mightier a variety of elements such as a large number of application that with function stabler machine tool permits to use taller cutting to process data speed, hard, environmental protection consciousness that increases increasingly are common the result of action. Code of new environmental protection law will increase the cost that uses cooling lubricating fluid, this promoted the development of dry type cutting, also ask to use high temperature resistant coating hard metal morely at the same time, normally this also can promote metallic cutting industry to consider to accept new means of settlement. The trend of a few development with metallic cutting the most fundamental market is as follows: Use higher cutting rate to improve productivity; Use dry type cutting and territory to reduce cost and protective environment least quantity is lubricant (MQL) cutting; Use difficult treatment data to reduce spare parts and structural weight (namely) of high strenth material. All these development take advantage of a favorable situation right the wearability of cutting cutting tool, fight be out of shape ability and tenacity raised taller requirement. Al2O3 has very tall chemical stability and good hot character, it is the coating material of ideal of cutting tool of high speed cutting. What need to emphasize in addition is, CVD is remained can the unique technique measure of coating of 2O3 of high quality of economic ground production. Although CVD Al2O3 coating is in the document of major science and technology that wear-resisting coating domain publishs is concerned PVD technology, but realise the past a few years li of CVD coating technology (especially Al2O3 coating technology) taking significant progress is crucial. Nowadays, already can carry the Al2O3 coat that the CVD craft deposit that can charge differs 3 kinds (A-Al2O3, k-Al2O3 and G-Al2O3) . The stability of A-Al2O3k-Al2O3g-Al2O3 of characteristic Al2O3 photograph that expresses the Al2O3 photograph that 1 stability and metastable decide stabilizes metastable to decide metastable to decide brilliant of crystal system triangle is department of inclined square brilliant cubic brilliant fastens parameter of crystal lattice of dimensional group D63d=R3cPna21Fd3m (Å) : A=4.

7587, c=12.

9929, inclined square hexahedral brilliant fastens N=6 (R):A=5.

12, a=55.

17 ° , n=2a=4.

8351b=8.

3109a=7.

The O atomicity 18(h)/6(R)2432a-Al2O3 in the afterbirth of single crystal of Al atomicity 12(h)/4(R)1663/3 in afterbirth of 92 single crystal is the Al2O3 photograph that stabilizes exclusively, the quantity of heat of the generation in the K photograph that metastable decides and the heat treatment after G will carry the heat treatment in be like deposit, deposit and cutting treatment and the A photograph with stable translate into. The certain character of photograph of these 3 kinds of Al2O3 sees a table 1. Graph the 1 Al2O3 that forms by 4 A-Al2O3 of alternant deposit and 4 K-Al2O3 is multilayer coating. The photograph of Al2O3 is controlled by the nucleate technology measure that establishs beforehand before deposit, k-Al2O3 and A-Al2O3 with identical craft parameter deposit people discovers surprisingly, the K-Al2O3 difficulty that the A-Al2O3 of deposit stability in using CVD craft to be produced in industry wants to compare deposit metastable state is gotten much, its are K-Al2O3 so formerly in the TiC that has Fcc structure, Ti(C, of N) or TiN coating did not oxidize the surface forms nucleus more easily. The K-Al2O3 of nucleate is right now opposite stabler, can grow form thicker coating (> 10µm) . Accordingly, if nucleate surface is TiC, Ti(C, n) or TiN(this kind of circumstance has typical sex) to hard alloy coating, with CVD craft cannot direct nucleate and grow A-Al2O3. This also can explain K-Al2O3 regards coating material as the account that is used extensively partly. Heretofore still has a lot of CVD Al2O3 coating that commercialize production to be formed by K-Al2O3. Recently, just drive the latest technology that gave out the CVD Al2O3 coating that can realize industrialized production, this technology can come through controlling nucleate process in the round deposit A-Al2O3 and K-Al2O3 coating. The graph shows the A-Al2O3 that can charge nucleate technology deposit to use and K-Al2O3 coating 1 times. The Al2O3 in the graph is multilayer coating is mixed by 4 A-Al2O3 of alternant deposit place of 4 K-Al2O3 coating is formed. The photograph of Al2O3 is to be before deposit Al2O3 by pilot of nucleate technology measure, all monolayer L2O3(a-Al2O3 and K-Al2O3) coating with identical craft parameter deposit. Use this technology to be able to control the photograph construction of CVD 2O3 coating completely. As above, k-Al2O3 is metastable phasing, can be in deposit process or cutting treatment (it is especially when high speed cutting) the A-Al2O3 photograph with stable translate into. The bulk systole that happens when changing will be reduced and destroy the adhesiveness of K-Al2O3 coating finally. Accordingly, the deposit effect that considers coating and wear-resisting caustic function (it is especially when high speed cutting) , a-Al2O3 photograph should be optimal with the safest choice. Of craft of deposit of coating of A-Al2O3 of article key attention optimize further. Basis " international crystal learns to express " in adoption definition, a-Al2O3 belongs to trigonometry brilliant department, have with inclined square hexahedral the hexagon crystal lattice that is a center, dimensional group symbol is R3c. The crystal structure of A-Al2O3 is like by up to by described as normally Hcp is arranged (... ABAB... ) oxygen is ionic (A, b) is formed, the ion that lose aluminium held the 2/3 of octahedral space. aluminous ion is in by statified and ordinal arrange (... Abgbg... ) the room that 3 can hold to differ in oxygen crystal lattice. This is the Ca that says normally, Cb and Cc. The brilliant afterbirth of A-Al2O3 includes 6 oxygen and aluminium, usable and following means describes: AcaBcbAcgBcaAcbBcg. Express 2 experiments to use face of nucleate of coating of A-Al2O3 coating Al2O3 ATi(C of ply of photograph crystal organization, n) , the Fcca(100) ～ 8E that the classics of Fcca(104) ～ 8D that the classics of Fcca(102) ～ 8C that classics of Fcca+k- ～ 8B handles handles handles is the same as 1 watch of Ca(104) ～ 3 deposit Al2O3 and Ti(C, the Al2O3Ti(C of parameter of craft parameter craft that N) layer uses, n) temperature (℃ ) 1000860 time (Min)560/60120 pressure (M Bar)8050H2(vol%) balances Ar(vol%) 100N2(vol%) -18CO2(vol%) 4 evenly.

2-AlCl3(vol%)4.

0-H2S(vol%)0.

4-TiCl4(vol%)-2CH3CN(vol%)-0.

The deposit experiment of coating of 8HCl(vol%) 212 experiment uses A-Al2O3 coating is the CVD that uses in an industry production deposit of system of AlCl3-CO2-Ar-H2-HZ2 gas phase uses in the reaction furnace (deposit temperature 1000 ℃ ) . In all deposit 5 kinds of different A-Al2O3 coating (E of coating A ～ , see watch 2) . Coating A deposit is in a Fcc apparently, did not take any special nucleate craft step; And E of coating B ～ is deposit the Fcc that handles in the course apparently. The crystal organization that Al2O3 coating grows can pass different nucleate technology measure to try to control, this are already clear. In this experiment, adopted 3 kinds of different nucleate technology measure. A of measure of these different nucleate technology important distinction depends on the potential oxidation ability of deposit furnace atmosphere, the change of deposit furnace atmosphere from make an appointment with B) of 5ppm H2O(coating to arrive make an appointment with D) of 20ppm H2O(coating. Those who need ambitious shift is, all experiments use Al2O3 coating (A ～ D) is to use identical craft parameter deposit, exclusive distinction depends on nucleate measure differring. Besides deposit time, the craft parameter that place of deposit coating E uses and place of deposit coating C use craft parameter identical, the deposit time of coating E is 60 minutes, and the deposit time of D of coating A ～ is 560 minutes. The craft parameter that deposit Al2O3 layer uses sees watch 3. A-Al2O3 coating deposit is in Ti(C, n) is coating to go up, ti(C, n) is used for the layer in deposit of lukewarm CVD(MTCVD) craft, deposit temperature makes an appointment with 860 ℃ , place sees a table with craft parameter 3. D of coating A ～ by make an appointment with the Ti(C with thick 2µm, n) is the Al2O3 layer composition with thick 8µm of layer peace treaty, coating E criterion by make an appointment with the Ti(C with thick 2µm, n) is the A-Al2O3 layer composition with thick 1µm of layer peace treaty. All coating all deposit is in K kind on hard alloy block-printed edition, the WC content 94wt% of block-printed edition, co content 6wt% , room temperature hardness makes an appointment with 1600HV10. The analysis uses instrument of X ray diffraction (lens of report of XDR) , scanning (SEM) and transmission report lens (TEM) undertakes study with coating to the experiment. SEM considers to be on lens of report of a LEO Ultra 55 FEGSEM undertake; The CM200 FECTEM report that TEM studied to provide system of Link I-SIS EDS in undertakes on lens, the method of preparation of section plane film that TEM studies to use can achieve the electronic diaphaneity of penetrable and whole coating. CuKa ray is used to undertake XDR studies on system of a Philips PW1050. The working parameter that X ray is in charge of is 40kV/40mA. The crystal of A-Al2O3 coating organizes coefficient (TC) can press type calculates: IC(hkl)=I(hkl){1 ∑ > in I(hkl)}-1I0(hkl)nI0(hkl) type, i(hkl) is measure (Hkl) reflexes intensity, i0(hkl) is the pulverous diffraction that according to JCPD 46-1212 blocking bugle call gets intensity, n is the reflection number that uses in computation. The index is given in hexagon system, because this used 4 rods (Hkil) , exponential I is the reciprocal of a two digit the sum, namely (H+k)=-i. Used the following (Hkil) reflex: (1012) , (1014) , (1120) , (1123) , (1126) and (3030) . (2024) reflex is (2 class reflex 1012) catoptric, because this is in computation,omit not plan. Cutting experiment is opposite with coating razor blade ferrite one pearlite steel (C=0.

45wt% , ck45) undertook fore-and-aft turning experiments, in order to evaluate its cutting performance. All experiment razor blade are opposite with XRD the photograph of Al2O3 and crystal organization undertook detecting. Turning experiment is falling without cooling condition undertake, the 4 cutting blade of experiment razor blade parts turning 2 minutes, 5 minutes, mix 15 minutes 9 minutes. After the workpiece material that cleans the adhere on bit with the HCl solution of boil, with scanning report lens (SEM) and optical microscope (OM) undertakes study to bit. Use coating bit to the experiment, have cutting tool life test additionally according to ISO 3685 standard even. The cutting requirement that cutting experiment adopts is as follows: Workpiece: Data of circular club material: Ck45, model of SS1672 razor blade: SNUN12O4O8 cutting speed: 300m/min feed leads: 0.

4mm/r cutting deepness: 2.

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