最新色国产精品精品视频,中文字幕日韩一区二区不卡,亚洲有码转帖,夜夜躁日日躁狠狠久久av,中国凸偷窥xxxx自由视频

Abstract:The CALPHAD technology,first principle method and Embedded Atom Method (EAM) in computer simulation of metals and alloys are outlined.Recent results of computer simulation for Ti2AlNb based alloy are reviewed.

Abstract:The development status of dental Ti, Ti alloys and Ti alloy porcetains, such as their physico mechanical properties, shaping techniques and equipments, and surface treatment, are reviewed. The present status of research and application of dental Ti and Ti alloy are discussed.

Abstract:Mg Ni alloy is a promising candidate for hydrogen storage because of its high discharge capacity. But its applicability is restricted by its rapid capacity deterioration and charge discharge cycling limitations. Factors effecting Mg Ni electrode discharging capacity are analysed and several methods for improving the overall electrochemical performance are discussed.

Abstract:在440℃經(jīng)多向鍛造加工成7075鋁合金鍛件。研究了鍛件的顯微組織和力學(xué)性能隨退火溫度和T73回火的變化，TEM和SEM用于分析鍛件的晶粒和第二相形態(tài)。多向和大變形鍛造產(chǎn)生平均晶粒尺寸1．8μm的完全再結(jié)晶組織。390℃-450℃退火使晶粒長大到3μm，但位錯和第二相分布沒有明顯改變，這時鍛件展現(xiàn)出較低強(qiáng)度和較高延性。T73回火使鍛件屈服強(qiáng)度和拉伸強(qiáng)度分別提高280％和210％，而延性同退火樣相比并無明顯下降，斷裂韌性達(dá)到51MPam^1/2，可以認(rèn)為這是沉淀強(qiáng)化的貢獻(xiàn)。

Abstract:The microstructure of oxide film for new zirconium alloys was studied.The results show that the microstructure of oxide films is much alike from inner surface to outer surface for NZ2 and NZ8 alloys by different intermidiate annealling treatment.The effect of different annealling lies in that whether there are precipitates embedding in oxide,the higher the accumulative annealing parameters,the more the probability of precipitates embedding.The embedded precipitates promote oxide transition to monoclinal structure and promote cracking along the former alloys grain boundary.SEM shows that the oxide film grows in a inhomogeneous way.The film in the inner surface appears in morphology like Cauliflouer,which is realted to accelerating corrosion.The faster the corrosion,the bigger the "Cauliflower"in size is.The results obtained by this study comfirm that adopting low temperature working process can make further refining of precipitates size,and this is the effective way to improve corrosion resistance of new zirconium alloys.

Abstract:研究了TiC粒子增強(qiáng)的鈦基復(fù)合材料的室溫軸向高周疲勞性能。測試Kt=1的試樣時采用的試驗頻率為76Hz，R＝0．06和R＝－1時，復(fù)合材料的室溫疲勞強(qiáng)度分別為594MPa和494MPa。試驗結(jié)果表明TiC粒子增強(qiáng)的鈦基復(fù)合材料的室溫高周疲勞性能與細(xì)晶組織的Ti-6Al-4V和IMI834的相當(dāng)。復(fù)合材料內(nèi)含有較細(xì)小的薄片狀組織，這種組織為α β相互相交錯構(gòu)成，這種細(xì)小的α β相間的層狀組織對于阻止疲勞裂紋的擴(kuò)展和提高疲勞裂紋的擴(kuò)展壽命有重要作用。退火后的復(fù)合材料疲勞裂紋擴(kuò)展區(qū)規(guī)則且較寬廣，從而也使復(fù)合材料具有較高的疲勞強(qiáng)度，疲勞裂紋擴(kuò)展壽命延長。

Abstract:The influences of the 1%HF solution pretreatment on electrochemical properties of ZrCr0.7Ni1.3 were investigated.The results show that creak initiation and propagation and the increase of the specific surface area were accelerated due to the effect of the microcell corrosion during the HF pre treating,therefore the electrochemical properties of the alloy were improved. The changes of surface morphology and composition of the alloy resulting from the HF pre treatment are responsible for the improvement in the electrochemical properties of the alloy.

Abstract:采用電化學(xué)測試技術(shù)研究了離子注氮對SUS316L不銹鋼，Co-Cr合金，工業(yè)純鈦和Ti-6Al-4V植入合金在Hank’s人工模擬體液中腐蝕行為的影響。腐蝕電位和極化曲線的測量結(jié)果表明，注氮使4種植入金屬材料的腐蝕電位正移，鈍化電位區(qū)間擴(kuò)大，耐蝕性明顯提高。注氮的工業(yè)純鈦和Ti-6Al-4V合金的耐蝕性最佳，其鈍化區(qū)拓寬為4V以上。通過AES分析發(fā)現(xiàn)，離子注氮后鈦及其合金表面形成的氮化鈦膜層及彌散的氮化鈦析出相的化學(xué)效應(yīng)，使基體電化學(xué)性能得到提高。注氮的Co-Cr合金的耐蝕性略優(yōu)于SUS316L不銹鋼。Co-Cr合金表面形成的鈷氮化合物相對基體起到保護(hù)作用，降低了腐蝕速率。SUS316L不銹鋼表面形成鐵和鉻氮化合物膜，有效地阻止了Cr^3 的水解，且氮離子注入促進(jìn)Fe3O4的產(chǎn)生，提高了耐腐蝕性能。

Abstract:通過建立熱力學(xué)可能反應(yīng)模型，分別計算了SCS－6 SiC長纖維增強(qiáng)Ti3Al和TiAl金屬間化合物基復(fù)合材料界面反應(yīng)的Gibbs函數(shù)變值△rG，并用△rG判據(jù)推測了界面反應(yīng)產(chǎn)物并與透射電鏡實(shí)驗結(jié)果進(jìn)行了對比分析。研究表明，由于TiAl中原子結(jié)合力較強(qiáng)，因而SCS－6 SiC/TiAl復(fù)合材料的界面反應(yīng)較輕。所研究的2種復(fù)合材料界面反應(yīng)的二元反應(yīng)產(chǎn)物為TiC,Ti5Si3和Ti3Si,Ti-Si相圖中的其它二元硅化物不可能形成。

Abstract:Specially designed SEM in situ fatigue tests have been conducted to trace the whole process of crack initiation and propagation to fracture in an Al2O3 seeded P/M Rene 95 superalloy.The results show that the loading wave shape has a strong effect on the micromechanical behavior.Under triangle wave loading crack initiation and propagation life decrease on the inclusion/matrix interface,but specimen failure is not due to the surface or sub surface inclusions.On the other hand,sine wave loading is accompanied by a significant increase the crack initiation life and surface or sub surface inclusions are always the primary cause of fatigue fracture.Furthermore,under the same loading waveform the crack initiation life increases as the amplitude of applied stress decreases.

Abstract:According to XRD the alloys Mn15Bi34Te51 and La15Bi34Te51 were formed after ball milling for 150 h and 100 h, respectively. Nanostructured La15Bi34Te51 resulted from extending the ball milling time to 150 h, It is suggested that the addition of La may refine the grain size and help to promote amorphism in Bi2Te3 based alloys. Further detailed XRD analysis of La15Bi34Te51 alloys suggests that the La atoms may intercalate between the Te Te layers of the Bi2Te3 layer structure. The Seeback coefficient measurements on the La15Bi34Te51 alloys indicates that the carrier scattering mechanism changes when the grain sizes are decreased to a few nanometers leading to a dramatic increase in the Seeback coefficient.

Abstract:Pure and metal oxide doped nanocrystalline ceria has been prepared by the hydrothermal technique,and the samples annealed at different temperatures to study the interaction between dopants and the ceria.The results indicated that CdO enhanced the growth of ceria particles while Al2O3 and ZrO2 hindered it.MgO,CaO,SrO and BaO only hindered the ceria particle growth at lower temperatures.At higher temperatures,as the impurity phases crystallized,they no longer hindered the growth of ceria particles.

Abstract:對TiAl合金渦輪的立式離心熔模陶瓷型殼精密鑄造進(jìn)行了研究，合金熔配設(shè)備為水冷銅坩堝真空感應(yīng)熔化爐。首先研究了TiAl合金鑄造時的尺寸收縮問題，結(jié)果表明1600℃澆注時，合金的收縮率為1．32％，隨著澆注溫度的提高凝固收縮率顯著提高。從合金熔體立式離心力場下充型模式方面考慮，渦輪澆注工藝應(yīng)采用類似于重力充型的底注式較好。TiAl合金渦輪離心澆注內(nèi)部組織致密、無氣孔，存在的主要問題是欠澆缺陷，迎流面充型較弱?？梢詮奶岣唠x心轉(zhuǎn)速和澆注溫度兩方面解決欠澆缺陷，但離心轉(zhuǎn)速提高帶來的安全隱患以及提高澆注溫度帶來的粘砂問題還需進(jìn)一步研究。

Abstract:An airtight joint between high purity Al2O3 and the alloy Kovar was obtained using a partial transient liquid phase(PTLP) bonding technique with Ni Ti filler.A sandwich structure was observed in the soldered joint two side faces of the sandwich were Ti2Ni and at the center was thick layer of Ti solid solution.Shear testing indicated that the joint strength increased with increase of holding time,although a relationship between strength and joining temperature was not observed.

Abstract:研究了WC-8%Co硬質(zhì)合金的粉末注射成形工藝,考查了不同氣氛和脫脂方法對脫脂坯碳含量的影響及燒結(jié)溫度、保溫時間對合金強(qiáng)度的影響,以及固體粉末裝載量對產(chǎn)品尺寸精度及保形性的影響。結(jié)果表明:溶劑脫脂+75%N2/25%H2混合氣體熱脫脂工藝,不僅能大幅度提高脫脂速率,而且有利于合金碳含量的控制。提高試樣固體粉末裝載率有利于提高制品密度和尺寸精度。在1460℃燒結(jié),保溫2h,PIM硬質(zhì)合金試樣的抗彎強(qiáng)度、硬度、密度分別達(dá)到2480MPa,HRA900MPa,和14.72g.cm-3;燒結(jié)后制品保形性良好,尺寸偏差為±0.02mm;斷口檢查和金相檢驗沒有發(fā)現(xiàn)任何明顯缺陷,合金組織均勻;平均晶粒度為2μm,孔隙度為A02B00,無石墨夾雜和η相出現(xiàn)。

Abstract:采用微弧氧化對鈦合金表面改性，討論在不同條件下微弧氧化膜的形貌、結(jié)構(gòu)和成份。結(jié)果表明，在鈦合金表面得到一層金紅石型TiO2和銳鈦礦型TiO2的多孔氧化膜，且在膜中可以滲入鈣，磷離子。膜層中的元素呈階梯分布，外層的Ca,P含量較大，Ca/P含量隨溶液中Ca/P含量近似呈線性增強(qiáng)。在確定的電解液下表面孔隙率基本不變，但孔洞大小隨反應(yīng)電壓的增加而增加；膜的生長速率隨反應(yīng)時間的延長呈先快后慢變化。這種含有Ca，P成份的多孔表層結(jié)構(gòu)有利于骨細(xì)胞的吸附和結(jié)合。

Abstract:Nanocrystalline CeO2 was prepared by hydrothermal crystallization method. XRD analysis indicates that the structure of the synthesized CeO2 is cubic with space group O5H FM3M. TEM photos reveals that nanocrystalline CeO2 is spherical in shape with a mean particle size of less than 100 nm. It was found that with increase of hydrothermal treatment temperatures the relative density of CeO2 nanocrystalline increased.

Abstract:在研究了貴金屬Pd和離子Pd2+催化劑對納米結(jié)構(gòu)厚膜材料氣敏特性的影響之后,提出了納米催化效應(yīng)的見解。認(rèn)為將微量Pd2+的水溶液加入到納米晶SnO2-x粉體中,可使Pd2+離子均勻地分布。所形成的PdO1-x納米晶,能更均勻地存在于納米結(jié)構(gòu)厚膜材料載體中,有望對可燃性氣體起到最有效的納米催化作用。實(shí)驗結(jié)果表明當(dāng)Pd2+離子最佳的引入量為1.04mol%時,對3000×10-6甲烷的靈敏度可達(dá)9～11。

Abstract:選取平均粒度為２．０μm的W粉末，小于４８μm的羰基Ni粉末和小于７４μm的羰基Fe粉末，純度大于９９％。按照９０W－７Ni－３Fe配成合金粉末。先期投入４９％Ni，２１％Fe以及３０％的W粉末（均質(zhì)量分?jǐn)?shù)）球磨８h后，再加入余量的W粉末球磨至２２h，球料比為４∶１，停機(jī)后在真空中干燥。利用冷等靜壓成型得到７mm×６０mm的試樣棒。將試樣棒埋在Al２O３粉中，置于空氣燒結(jié)爐中加熱至４５０℃，經(jīng)過３０min的保溫預(yù)氧化后，再經(jīng)不同溫度在氨分解的氫氣氛（低于－２０℃的露點(diǎn)）中燒結(jié)，最后以５０℃／min的速率冷卻到室溫，為進(jìn)一…