烧结温度和成分对Al_2O_3-TiC复合材料力学性能影响

以α-Al2O3粉、TiC粉为原料,采用热压烧结工艺制备了Al2O3-TiC复合材料,系统研究了烧结温度以及成分对Al2O3-TiC复合材料的组织结构和力学性能的影响规律.结果表明:α-Al2O3与TiC间没有发生化学反应,两相间具有很好的化学相容性.TiC的引入有利于提高Al2O3-TiC复合材料的力学性能.1 600℃热压烧结的Al2O3-20%TiC复合材料具有最佳的力学性能,其抗弯强度和断裂韧性分别达到509.45 MPa和5.27 MPa·m1/2,复合材料的断裂方式主要是沿晶断裂,同时伴有穿晶断裂.     

放电等离子烧结参数对Fe_(76)Si_9B_(10)P_5非晶合金致密化及晶化的影响

采用放电等离子烧结(Spark Plasma Sintering,SPS)方法,在不同的烧结温度、保温时间、升温速率和烧结压力下,固结Fe76Si9B10P5非晶粉末。用差式扫描量热仪测定了非晶粉末的过冷液相温区,用X-ray衍射方法分析了放电等离子烧结前后样品的相结构,研究了SPS法烧结参数对Fe76Si9B10P5非晶样品致密化及结晶化的影响,并在非晶粉末的玻璃转变温度以下快速烧结制备了尺寸为Ф15×3 mm的块体非晶合金,致密度达98.7%。     

放电等离子加压烧结(SPS)技术特点及应用

放电等离子加压烧结技术(SPS)是材料合成与加工领域的一种新技术。本文综合介绍了SPS技术的发展概况、特点及在材料制备中的应用。通过比较SPS技术与HP、HIP等材料合成技术的异同点,对SPS技术的发展前景进行了展望     

球磨对放电等离子烧结TiB2陶瓷的影响

研究了不同球磨处理工艺获得的TiB2粉末的物相及颗粒形貌，不同的原始粉末对SPS烧结效果产生不同的影响。研究结果表明：球料比（5：1)、球磨8h的TiB2粉末具有最好的烧结效果，其SPS烧结温度为1700℃，比热压烧结纯TiB2低100℃左右；烧结体的相对密度达到99％以上，平均粒径约为5μm，与低温液相热压烧结相当。     

放电等离子烧结制备碳化钛块材研究

利用放电等离子烧结（SPS）对碳化钛（TiC）/氢化钛（TiH2）混合粉末进行烧结以制备块材。利用X射线衍射（XRD）并结合Rietveld精修法对块材进行定性与结构分析;借助扫描电子显微镜（SEM）对块材断面微观形貌进行观察;测试了块材硬度并探讨SPS技术制备TiC块材的致密化过程与反应机理。结果表明：混合粉末经SPS烧结,获得了高度致密的TiC块材;与传统烧结方法比较,SPS技术更具低温快速性。     

Fe离子注入Al_2O_3陶瓷改变其表面电阻率的研究

本文研究了Fe离子注入Al_2O_3陶瓷的注入射程、纵向浓度分布和注入层结构,测定了注入层中的载流子浓度和迁移率,讨论了Al_2O_3陶瓷注入Fe离子其表面层的导电机理。其结论是:注入的Fe~(2-)离子进入Al_2O_3晶格,替代了Al~(3-)离子形成替位杂质。这样注入离子与原有晶格比较呈现一个有效负电荷,形成负电中心。它可以把一个空穴束缚在它的周围,在禁带引入受主能级。     

放电等离子快速烧结C/BN层状复合材料

采用放电等离子烧结技术（SPS）快速烧结了C／BN层状复合材料，研究了烧结工艺、结构和性能之间的关系。材料的微观结构分析表明，随着温度的升高和保温时间的延长，石墨基体与BN层间的结合逐渐增强；耐热冲击试验表明，在烧结温度1750℃，保温5min左右时，材料可经受40次左右循环；材料的界面结合强度最高可以达到18．2MPa．显示了较好的力学性能。     

纤维体积分数对 Al_2O_(3f)/ZA22 复合材料拉伸强度的影响

采用日本产ＡＧ １０ＴＡ型电子万能试验机对不同纤维体积分数的挤压铸造Ａｌ２Ｏ３ｆ／ＺＡ２２复合材料的拉伸强度进行了测定。采用Ｆｒｉｅｎｄ修正的混合律模型对纤维体积分数较小时该类复合材料拉伸强度低于基体合金强度这一现象进行了深入分析。理论分析与试验结果吻合较好。在本试验条件下,求得纤维强化临界体积分数Ｖｃｒｉｔ为２３６％,超过该值,复合材料强度高于基体强度。     

直接氧化法制备Al_2O_3/AI复合材料研究

介绍了应用直接氧化法制备用Al_2O_3/Al复合材料的工艺技术问题,研究了合金元素、氧化温度对Al_2O_3生长动力学的影响,以及不同合金、不同温度和不同时间反映产物的显微组织与结构及其力学性能,找出了适合Al_2O_3生长的合金成分、生长温度与时间.     

Synthesis and Sintering of Mg2Si Thermoelectric Generator by Spark Plasma Sintering

Raw Mg,Si powder were used to fabricate Mg2Si bulk thermoelectric generator by spark plasma sintering (SPS).The optimum parameters to synthesize pure Mg2Si powder were found to be 823 K,0 MPa,10 min with excessive content of 10wt% Mg from the stoichiometric Mg2Si.Mg2Si bulk was synthesized and densified simultaneously at low temperature (823 K) and high pressure (higher than 100 MPa) from the raw powder,but Mg,Si could not react completely,and the sample was not very dense with some microcracks on the surface.Then,Mg,Si powder reacted at 823 K,0 MPa,10 min in SPS chamber to form Mg2Si green compact,again sintered by SPS at 1023 K,20 MPa,5 min.The fabricated sample only contained MgESi phase with fully relative density.     

W-Sc2O3靶材的SPS制备和性能研究

采用溶胶凝胶法加二段还原, 制备出晶粒直径500~1100 nm的亚微米W-Sc₂O₃粉末, 利用放电等离子烧结(spark plasma sintering, SPS)制备了W-Sc₂O₃靶材.对不同粉末处理条件下的W-Sc₂O₃烧结体的密度、硬度、表面形貌进行测试研究.结果表明, 亚微米尺度的W粉在1 300℃即可烧结, 远低于常规W粉烧结温度, 获得的烧结体相对密度达96.4%、硬度为86.4HRC且Sc元素分布均匀.     

Fabrication of MoSi2-SiC Composites by a Spark Plasma Sintering Method

MolybdenUmdisilicidepeoSi,)hashighmeltingpoint(2293K),relativelylowdensity(6.249/cm3),abrittle-to-ductiletemper~atabout1173K[l]andoutstandingoxidationresistance[2M].Forthisreason,thedisilicidematrixcompositesarebeingconsideredasoneofthemoStPromisingc...     

Fabrication and Microstructure Evolution of Niobium-Niobium Silicide Composites by Spark Plasma Sintering

By using Nb and Si elemental powders as raw materials,dense Nb/Nb 5 Si 3 composites were successfully fabricated by a spark plasma sintering(SPS)technology.The microstructure of the fabricated composites was analyzed by OM,SEM,XRD and EPMA;the microstructure evolution of the composites was also investigated by a quenching test.The experimental results show that the prepared composites consist of Nb and Nb 5 Si 3 phases;Nb particle uniformly distributes in the in-situ synthesized Nb5 Si3 matrix.During the SPS process,an interfacial reaction occurs between Nb and Si particles to synthesize Nb 5 Si 3 until reactant silicon has been completely depleted.     

Fabrication and Microstrueture Evolution of Niobium-Niobimn Silicide Composites by Spark Plasma Sintering

By using Nb and Si elemental powders as raw materials, dense Nb/NbsSi3 composites were successfully fabricated by a spark plasma sintering （SPS） technology. The microstructure of the fabricated composites was analyzed by OM, SEM, XRD and EPMA; the microstructure evolution of the composites was also investigated by a quenching test. The experimental results show that the prepared composites consist of Nb and Nb5Si3 phases; Nb particle uniformly distributes in the in-situ synthesized Nb5Si3 matrix. During the SPS process, an interfacial reaction occurs between Nb and Si particles to synthesize Nb5Si3 until reactant silicon has been completely depleted.     

Spark Effect on the Densification of SiCp/Al Composites by SPS

1 IntroductionSiCp/Al composites have aroused considerable inter-ests in manyfields of industry due to their tailorable me-chanical and thermophysical properties .SiCp/Al compos-ites have been developed mainly as structural materials inapplicationfor automobile industries and aerospace indus-tries . However ,thermal management applicationsin elec-tronic packaging,such as substrates ,heat slugs and heatspreads have been focused on. Electronic componentsused in thermal management applications …     

烧结助剂对氧化铝陶瓷低温烧结的影响

氧化铝(Al_2O_3)陶瓷烧结温度较高,通过添加烧结助剂可以实现Al_2O_3陶瓷的低温烧结。对比分析了不同含量的CuO-TiO_2和MnO_2-TiO_2-MgO复合烧结助剂在不同的烧结温度下对Al_2O_3烧结性能的影响,得到了烧结助剂含量和烧结温度对Al_2O_3陶瓷体积收缩率、体积密度以及内部显微结构的影响规律。实验分析表明,在1 350℃的烧结温度下,添加4%(质量分数) CuO-TiO_2和MnO_2-TiO_2-MgO的烧结助剂,Al_2O_3陶瓷分别能获得高达3. 67 g/mm~3和3. 76 g/mm~3的体积密度,并且在扫描电子显微镜下观察到良好的显微结构。     

TiC含量及烧结温度对Al2O3-TiC复合陶瓷材料力学性能的影响

利用热压烧结法制备了Al2O3-TiC复合陶瓷材料,研究了TiC含量、烧结温度对材料致密度、抗弯强度、断裂韧性等性能的影响.结果表明:TiC颗粒的引入,可以有效提高Al2O3-TiC复合陶瓷材料的力学性能,当TiC含量为30Vol%、烧结温度为1 750℃时,Al2O3-TiC复合材料的断裂韧性值和抗弯强度值达到最大,分别为5.08 MPa·m1/2和620 MPa,试样的断裂方式主要为沿晶断裂,同时也含有穿晶断裂.     

The Influence of Mo Additive on the Microstructure and Property of Ti/Al_2O_3 Composite

1　IntroductionBecausethemetal ceramiccompositeisalwaysfabri catedatahightemperature ,theinterfacialreactionbe tweenmatrixandreinforcementisinevitableandformsabrittleinterfacialzone ,whichisdetrimentaltocompositeproperties .Thisisthemaincauseforhinderingtheprepa rationandapplicationoftitaniummatrixcomposites .Atpresent,variousapproachescanbeadoptedtoinhibitorreducethereinforcement matrixreaction .Theuseofhigh speedandlowerprocessingtemperatureduringcompositefabrication ,settingaprotectivecoati…