网络首发时间: 2019-08-05 20:59

稀有金属 2021,45(03),288-296 DOI:10.13373/j.cnki.cjrm.xy19070012

溶胶凝胶/高温氢还原法制备纳米Mo-ZrO₂(Y₂O₃)复合粉末

康蓉 颜建辉 李茂键

湖南科技大学材料科学与工程学院

湖南科技大学高温耐磨材料及制备技术湖南省国防科技重点实验室

湖南科技大学新能源储存与转换新进材料湖南省重点实验室

摘 要：

纳米Mo-ZrO₂(Y₂O₃)复合粉末是一种很有发展前景的粉末冶金材料。采用溶胶凝胶法制备前驱体复合粉末,并对得到的前驱体复合粉末采用高温氢还原工艺制备Mo-ZrO₂(Y₂O₃)复合粉末。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和能谱分析(EDS)等分析检测技术对前驱体复合粉末的物相组成和微观结构进行表征,并分析不同的还原时间和温度对高温氢还原后Mo-ZrO₂(Y₂O₃)复合粉末的物相组成及微观组织结构的影响。结果表明,在400-650℃下煅烧后的前驱体粉末物相均由MoO₃组成;随着煅烧温度的升高,粉末形貌按照薄片状-片层状-长棒状规律演变;在保温3 h条件下,MoO₃还原成Mo的起始温度为550℃;如果采用一步还原的方法,煅烧产物MoO₃完全转换为Mo的还原温度必须高于650℃;溶胶凝胶结合高温氢还原能够制备纳米级别且纯度较高的Mo-ZrO₂(Y₂O₃)复合粉末,团聚的复合粉末由80-100 nm细小颗粒组成,ZrO₂(Y₂O₃)均匀地分布在Mo基体粉末中。

关键词：

Mo-ZrO(YO);纳米粉末;溶胶凝胶;高温还原;

中图分类号： TF125.241;TB383.1

作者简介：康蓉(1995-),女,陕西省渭南人,硕士研究生,研究方向:难熔金属及其化合物,E-mail:657974926@qq.com;*颜建辉,教授,电话:0731-58290847,E-mail:yanjianhui88@163.com;

收稿日期：2019-07-09

基金：国家自然科学基金项目(51475161);湖南省自然科学基金项目(2020JJ4025);湖南省研究生科研创新项目(CX20190837)资助;

Preparation of Nanometer Mo-ZrO₂(Y₂O₃) Composite Powder by Sol-gel and High Temperature Hydrogen Reduction

Kang Rong Yan Jianhui Li Maojian

College of Materials Science and Technology,Hunan University of Science and Technology

Hunan Provincial Key Defense Laboratory of High Temperature Wear Resisting Materials and Preparation Technology,Hunan University of Science and Technology

Hunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and Conversion,Hunan University of Science and Technology

Abstract：

Molybdenum and its alloys had a low coefficient of thermal expansion,superior electrical and thermal conductivities,good high-temperature strength and creep resistance,and excellent high-temperature dimensional stability. Therefore,as high-temperature components,molybdenum and its alloys were widely used in aerospace,electronic communications,electrical equipment,space vehicles and other high-temperature parts. However,to some extent,the low recrystallization temperature(about 1000 ℃),inherent brittleness and insufficient strength hindered their practical application. It was well known that ultrafine grained or nanocrystalline materials have better mechanical properties than that of the conventional coarse-grained materials. Therefore,preparing ultrafine grained or nanocrystalline composite materials was an effective way to enhance the mechanical properties. Moreover,Y₂O₃ partially stabilized ZrO₂ had a great potential in improving the comprehensive mechanical properties of molybdenum and its alloys. However,the study had not yet reported the preparation of the Mo-ZrO₂(Y₂O₃)nanometer composite powders. The nanometer Mo-ZrO₂(Y₂O₃)powders were prepared by sol-gel and high temperature hydrogen reduction,the details were as follows:Firstly,the raw materials of Zr(NO₃)₄·5H₂O,Y(NO₃)₃·6 H₂O and C₆H₈O₇·H₂O were dissolved in the distilled water according to a certain proportion and continuously heated with thermostat water bath cauldron at 85 ℃ to form wet gel. Secondly,the wet gel was dried at 110 ℃ for 10 h to obtain the dry precursor powder,and the powder subsequently calcinated at 400～650 ℃ for 5 h in a muffle furnace. At last,the effects of different reduction time and temperatures on the phase composition and microstructure of the Mo-ZrO₂(Y₂O₃)composite powders after high temperature hydrogen reduction were also analyzed. The reduction parameters were discussed as follows:(1)reduction time:the powders were reduced at 550 ℃ for 1～5 h in H₂ atmosphere;(2)reduction temperature:the powders were reduced at 350～900 ℃ for 3 h in H₂ atmosphere. Phase composition and microstructure of the precursor composite powders were investigated by X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM)and energy dispersive spectroscopy(EDS). The calcinated powders were composed of single MoO₃ when the dry precursor powders were calcined at 400 to 650 ℃ for 5 h. An increase in the grain size of the calcined powders was observed with the enhancement of the calcination temperature. When the calcination temperature was varying from 400 to 550 ℃,the calcined MoO₃ powders showed the characterization of lamellar and smooth microstructure,and the agglomeration phenomenon appeared in the powders. When the calcination temperature increased up to 600 or 650 ℃,the grain size of MoO₃ powders continued to grow. The powders showed the shape of rod after the dry precursor powders were calcined at 650 ℃. It indicated that the particle size distribution of the composite powders was relatively uniform after the dry precursor powders were calcined at 550 ℃ for 5 h. When the calcined powders were reduced at 550 ℃ for 1 h,the powders were composed of MoO₃ and a small amount of MoO₂,and the particles of the reduced powders showed the characterization of lamellar(MoO₃)and granular(MoO₂)morphologies. With extending the reduction time to 3 or 5 h,the diffraction peak of MoO₃ disappeared and the MoO₂ phase appeared,and a small amount of the Mo phase formed,which indicated that the reduction time of transforming MoO₃ to Mo phase at 550 ℃ needed at least 3 h. According to the relationship between reduction temperature and products,the reduction temperature could be pided into three stages. With an increase of the temperature from 350 to 600 ℃,MoO₃ powders were first reduced to Mo₄O₁₁ and subsequently amount of Mo. When the reduction temperature varied from 650 to 900 ℃,the products were composed of Mo. It was obvious that the temperature of reducing all the calcined MoO₃ powders to Mo should be over 650 ℃. When the reduction temperature was 350 ℃,the morphologies of the powders were lamellar(MoO₃)and granular(MoO₂). When the reduction temperature increased up to 450 ℃,the morphology of the powders gradually changed from lamellar to granular structure. After reducing at 550 ℃,the powder exhibited the irregular granular. When the reduction temperature was 600 ℃,the irregular granular particles gradually decreased and changed into the spherical Mo particles. When the reduction temperature was further increased up to 650-850 ℃,the agglomeration phenomenon of the powders was more obvious,and the agglomerated particles were composed of fine near-spherical particles. The Mo powder particles tended to grow up due to the high reduction temperature. The TEM image indicated that the agglomerated composite powders were made of nanometer Mo-ZrO₂(Y₂O₃)particle with the size of 80～100 nm,and the EDS results further proved that the composite powders were composed of Mo and ZrO₂(Y₂O₃)particles. In addition,Mo-ZrO₂(Y₂O₃)powders contained 0.11% C,1.53% O and 0.07% N. It indicated that the combination of sol-gel and high temperature hydrogen reduction could prepare the nano-grained and high purity MoZrO₂(Y₂O₃)composite powders. TEM analysis of Mo-ZrO₂(Y₂O₃)composite powders reduced at 750 ℃ for 3 h further confirmed that the composite powders were composed of nano-Mo and ZrO₂(Y₂O₃),and the elements of Zr and Y were uniformly distributed in the Mo matrix in the form of oxide ZrO₂ and Y₂O₃. The results showed that the compositions of the precursors,which were calcined at 400-650 ℃,were composed of MoO₃. With an increase in the calcination temperature,the morphologies of the powders evolved in the form of flakes-lamellar-long rods. The reduction temperature was 550 ℃ when MoO₃ were initially reduced to Mo. The temperature should be over 650 ℃ using a one-step reduction method when the MoO₃ was completely reduced to Mo powder. Nanometer Mo-ZrO₂(Y₂O₃)composite powder with high purity was prepared by sol-gel and high-temperature hydrogen reduction method. The agglomerated composite powder was made of nanometer Mo-ZrO₂(Y₂O₃)particle with the size of 80～100 nm,and ZrO₂(Y₂O₃)particles were uniformly distributed in the Mo matrix powder.

Keyword：

Mo-ZrO₂(Y₂O₃); nanometer powder; sol-gel; high temperature hydrogen reduction;

Received： 2019-07-09

钼及钼合金具有较低的热膨胀系数、优越的导电导热性能、良好的高温强度和抗蠕变性能以及优异的高温尺寸稳定性，这使钼及钼合金在航空航天、电子通讯、电气设备以及空间飞行器等高温部件领域中得到广泛的应用 ^[1,2,3] 。然而，钼属于难熔金属体系（熔点2620℃），纯钼的再结晶温度低（约1000℃）且具有固有的脆性属性。作为结构材料而言，钼及钼合金自身的缺点致使其高温应用受到一定的限制 ^[4,5,6] 。目前，这些问题解决主要是在钼及钼合金中添加稀土氧化物（La₂O₃,Y₂O₃等）或加入碳化物（Ti C,Zr C等），以第二相的方式来提高钼及钼合金的再结晶温度和高温强度。如：掺杂La₂O₃的Mo合金在高温下具有较高的再结晶温度（>1300℃）、优异的抗蠕变性和良好的室温延展性 ^[7,8] 。然而，Mo-La₂O₃复合材料在实际应用过程中，常因钼板残余应力较大导致板材容易开裂 ^[9] 。稀土Y₂O₃作为一种稳定的氧化物，加入Mo合金中不仅能有效抑制钼合金晶粒长大，使晶粒分布更加均匀，还能促进其致密化，并提高其综合力学性能。然而，Y₂O₃的毒性限制了Mo-Y₂O₃复合材料的广泛应用。

除了上述稀土氧化物或碳化物外，具有熔点高、硬度高、化学稳定性好以及价格低廉等优点的Zr O₂陶瓷作为理想的金属基强化相在增韧其它陶瓷和脆性金属间化合物方面越来越受到广泛研究者的青睐 ^[10,11] 。Cui等 ^[12] 报道了通过添加纳米Zr O₂可有效地细化Mo粉颗粒尺寸，从而明显提高Mo合金的拉伸强度和屈服强度。Wang等 ^[13] 采用共沸蒸馏法及热等静压工艺制备了硬度高和耐磨性好的W-1.5%Zr O₂（质量分数）合金，其抗压强度和临界断裂应变分别比纯W高出55.3%和98.1%。当Zr O₂从高温缓慢冷却至室温时，其晶体结构从立方相转变为单斜相（c-Zr O₂→m-Zr O₂) ^[14] ,Zr O₂晶体转变导致材料膨胀和收缩，降低材料的使用寿命 ^[15] 。然而，添加Y₂O₃氧化物，可以大大提高Zr O₂稳定立方相的温度范围。因此，Y₂O₃部分稳定的Zr O₂作为增强相，在提高钼合金的综合力学性能方面具有较大的发展潜力。

众所周知，超细晶甚至纳米晶比传统的粗晶材料具有更好的力学性能和机械强度。因此，关于超细晶和纳米晶复合材料的制备得到了科技工作者广泛的关注 ^[16,17] 。通过粉末冶金法制备超细晶钼合金是难熔金属的主要生产方法之一。在粉末冶金领域制备超细和纳米复合Mo粉的过程中，合理的掺杂方式对Mo基合金的综合性能有着重要的影响 ^[18] 。通常，将陶瓷Zr O₂颗粒以固态形式采用机械的方法掺杂到钼基体中，一般会导致Zr O₂颗粒在基体中分布不均匀，多分布于晶界上，且容易造成晶间腐蚀 ^[19] 。而液-液掺杂方式可以使Zr O₂颗粒从基体材料中原位生成，使基体与Zr O₂之间具有洁净的界面，且尺寸细小Zr O₂颗粒弥散均匀分布于基体中，这也有效地提高了合金的力学性能 ^[12,20] 。因此，本文中采用溶胶凝胶法，即液-液掺杂方式制备前驱体粉末，希望获得均匀性好的Mo-Zr O₂(Y₂O₃）复合粉末，以此来改善钼基复合材料的综合力学性能。

1 实验

按照Mo中Zr O₂(Y₂O₃）掺杂质量为1.5%进行配料。称取一定量的七钼酸铵（（NH₄)₆Mo₇O₂₄·4H₂O）于干净的烧杯中，加入适量蒸馏水，放进磁力搅拌器中搅拌，使其充分溶解。然后，按照一定比例分别称取适量的硝酸锆（Zr(NO₃)₄·5H₂O）、硝酸钇（Y(NO₃)₃·6H₂O）和柠檬酸（C₆H₈O₇·H₂O）于另一个干净的烧杯中，加入蒸馏水后进行搅拌，直至溶液混合均匀。再将两个烧杯中的溶液混合均匀后放于85℃恒温水浴锅中加热，当烧杯中溶液流动性很小且形成湿凝胶时，就停止水浴加热。将湿凝胶在110℃的恒温干燥箱中烘干，室温下经手工研磨后得到前驱体粉末。

将研磨后的前驱体粉末放入箱式电阻炉中进行煅烧，煅烧温度400～650℃，时间为5 h，煅烧结束后随炉冷却。选取550℃（5 h）的煅烧粉末置于高纯Al₂O₃坩埚中，在流动氢气气氛下的管式炉中还原，还原试验工艺分为：部分粉末在550℃还原1,3和5 h；部分粉末在350～900℃还原3 h。

采用D/max 2500型X射线衍射仪（XRD）对前驱体粉末和还原后粉末进行物相分析；用Quanta-200型扫描电子显微镜（SEM）和Quanta-250型场发射扫描电子显微镜（FESEM）观察前驱体和还原后粉末的形貌，并结合能谱分析（EDS）进行成分分析；利用FEI Talos F200s型透射电子显微镜（TEM）对复合粉末的形貌、衍射斑及元素分布进行表征；利用CS600碳硫测定仪和TCH 600氧氮氢分析仪对还原后的粉末进行碳、氧含量的测定。

2 结果与讨论

2.1 煅烧温度对前驱体粉末微观组织结构的影响

将干燥并研磨后的溶胶凝胶前驱体粉末在不同的煅烧温度（400,450,500,550,600和650℃）分别保温5 h，得到的前驱体复合粉末的XRD图谱如图1所示。可以看出，400～650℃温度下煅烧后粉末物相均由单一的Mo O₃组成，并未检测到其他物质，这表明400～650℃的煅烧温度对粉末的物相组成影响不大。随着煅烧温度的升高，Mo O₃粉体的衍射峰的强度逐渐增强，但衍射峰的位置并没有发生变化。另外，在550～650℃煅烧时，大多数衍射峰的强度明显增加，这归因于Mo O₃晶体在550～650℃温度区间的生长过程中的择优长大 ^[21] ，这也充分说明煅烧温度的升高有利于Mo O₃晶体的进一步长大，其结晶度会明显提高，同时也会导致晶粒尺寸增加。

图2为不同煅烧温度下得到的Mo O₃粉末的SEM形貌。可见，在煅烧温度为400和450℃时，部分Mo O₃粉末呈薄片状，细小的粉末之间存在明显的团聚现象。当煅烧温度为500℃时，大部分Mo O₃粉体为呈薄片状，粉体边缘不太圆滑，存在有一定棱角。当煅烧温度为550℃时，煅烧的Mo O₃粉体为片层状，粉末表面光滑平整，粉末之间的团聚现象消失，颗粒尺寸增大。当煅烧温度提高到600或650℃时，Mo O₃粉体尺寸继续长大，650℃时煅烧获得的Mo O₃粉体呈长棒状。由不同煅烧温度下Mo O₃粉末的组成和微观形貌可知，前驱体粉末在不同的煅烧温度下物相组成没有差别，但粉末在不同煅烧温度下的外观形貌发生了明显的改变。可见，前驱体粉末在550℃（5 h）煅烧后，复合粉末的粒度分布比较均匀。

图1 不同煅烧温度下制备粉末的XRD图谱

Fig.1 XRD patterns of powders calcined at different tempera-tures

图2 不同温度煅烧下生成Mo O3粉体的SEM形貌

Fig.2 SEM images of Mo O₃powders calcined at different temperatures(a)400℃；（b)450℃；（c)500℃；（d)550℃；（e)600℃；（f)650℃

2.2 还原工艺对Mo-Zr O2(Y2O3）粉末微观组织结构的影响

2.2.1 还原时间对Mo-Zr O2(Y2O3)粉末微观组织结构的影响

以550℃（5 h）煅烧的Mo O₃粉末为还原对象，在550℃还原不同时间（1,3和5 h）所得到的还原产物的XRD衍射图谱如图3所示。可见，还原1 h时，粉末主要由Mo O₃和少量Mo O₂组成，这表明还原1 h时，Mo O₃还不能完全反应生成Mo O₂。当还原时间延长至3或5 h时，Mo O₃衍射峰已完全消失，Mo O₃已经转化为Mo O₂，同时也产生了极少量的Mo。这表明Mo O₂在550℃温度下还原3 h就开始出现了单质Mo。由于Zr O₂(Y₂O₃）在Mo-Zr O₂(Y₂O₃）复合粉末中所占的质量分数很小，导致在图3的XRD图谱中很难检测到Zr O₂(Y₂O₃）物质的衍射峰。

图4为550℃下还原不同时间所得到粉末的SEM形貌。从图4(a）可以看出，当粉末被还原1 h时，还原粉末由片层状和无规则颗粒状两种不同的形貌的颗粒组成。图4(a）中区域A和B的EDS结果如图4(d,e）所示，结果表明区域A和B中的元素都是由Mo和O组成，区域A中的Mo与O原子比近似为1∶2，区域B中的Mo与O原子比近似为1∶3，这说明颗粒状为Mo O₂，而片层状为Mo O₃，这与550℃下还原1 h的XRD结果一致。当还原时间为3或5 h时，粉末形貌基本由颗粒状Mo O₂组成，且颗粒大小分布比较均匀。相对3 h而言，5 h还原后得到的粉末团聚现象加剧。与煅烧态的粉末（图2(d））相比，还原后粉末的粒度大幅度的减小。

图3 Mo O3粉末在550℃还原不同时间的XRD图谱

Fig.3 XRD patterns of Mo O₃powders prepared by reduction at 550℃for different time

图4 Mo O3粉末在550℃还原不同时间的SEM形貌和EDS能谱

Fig.4 SEM images and EDS result of Mo O₃powders prepared by reduction at 550℃for different times(a)1 h;(b)3 h;(c)5 h;(d)EDS result of Point A in Fig.4(a);(e)EDS result of Point B in Fig.4(a)

2.2.2 还原温度对Mo-Zr O2(Y2O3)粉末微观组织结构的影响

图5为煅烧产物Mo O₃在350～900℃温度区间还原3 h所得粉末的XRD图谱，各温度下还原产物的物相组成具体见表1。由5图和表1可知，根据还原温度和还原产物之间的关系，还原温度大致可以分为3个阶段：（1)350～550℃阶段（图5(a））。温度为350℃时，还原产物由主相Mo O₃和极少量Mo O₂和Mo₄O₁₁组成。当还原温度为450℃时，还原产物由Mo O₃,Mo₄O₁₁和Mo O₂这3种主相组成。当在550℃还原时，Mo O₃全部还原成Mo O₂，但出现了极少量的Mo。可见。在350～550℃区间还原时，Mo O₃先还原成中间产物Mo₄O₁₁，随着温度的升高，Mo₄O₁₁则进一步转变成Mo O₂。（2)550～600℃还原阶段（图5(b））。从图5(b）可知，在550℃时，粉末主要是Mo O₂，在2θ约40°时，出现了极少量单质Mo，这表明Mo O₂在此温度下可以还原为Mo。当还原温度升高到600℃时，Mo O₂的衍射峰基本消失，而Mo衍射峰却逐渐增加。（3)650～900℃阶段（图5(c））。在此还原温度区间，还原产物的物相组成相同，粉末全部由单质Mo组成，检测不到Mo O₂衍射峰。这说明在650℃时，H₂可将Mo O₂全部还原为金属Mo，没有任何中间产物出现。可见，从还原产物的组成来看，如果采用一步还原的方法，煅烧产物Mo O₃完全转换为金属Mo的还原温度必须高于650℃。

图5 Mo O3粉末在不同温度下还原产物的XRD图谱

Fig.5 XRD patterns of Mo O₃powder prepared by reduction at different temperatures(a)350～550℃；（b)550～650℃；（c)650～900℃

表1 不同还原温度下的粉末的组成  下载原图

Table 1 Phase composition of powders at different reduc-tion temperatures

表1 不同还原温度下的粉末的组成

Mo O₃粉体经过不同温度还原后得到的粉末SEM形貌如图6所示。可知，当还原温度为350℃时，粉末形貌主要表现为片层状Mo O₃和少量颗粒状Mo O₂。当还原温度升到450℃时，粉末形貌发生了明显改变，大部分片层状粉末逐渐演变为颗粒粉末。在550℃时，粉末主要由无规则颗粒状Mo O₂组成。当还原温度为600℃时，无规则颗粒状的Mo O₂逐渐减少，转变为近似球形形貌的Mo颗粒。随着还原温度进一步升高到650～850℃时，粉末团聚现象严重，团聚颗粒全部由细小的近球形颗粒单质Mo组成；而还原温度为850℃时，团聚现象更加明显，Mo粉末颗粒还有长大的趋势，这是因为更高的温度有助于颗粒的长大。图7(a,b）分别为850℃下还原3 h后的Mo-Zr O₂(Y₂O₃）复合粉末的SEM形貌和相应的EDS图。从图7(a）可知，MoZr O₂(Y₂O₃）复合粉末是由许多个纳米颗粒（80～100nm）团聚而成。图7(b）为图7(a）的EDS图，这进一步证明了粉末颗粒是由Mo和Zr O₂(Y₂O₃）组成。另外，Mo-Zr O₂(Y₂O₃）粉末的C含量为0.11%,O含量为1.53%,N含量为0.07%。可见，溶胶凝胶结合高温氢还原能够制备纳米级别和纯度比较高的MoZr O₂(Y₂O₃）复合粉末。

为了进一步确认Zr O₂(Y₂O₃）在Mo粉末中的存在性和分布均匀性，对750℃还原3 h后的Mo-Zr O₂(Y₂O₃）复合粉末进行TEM分析，复合粉末的形貌、粉末中的纯Mo和Mo-Zr O₂(Y₂O₃）复合粉末电子衍射分别如图8(a～c）所示，这进一步证明了复合粉末是Mo和Zr O₂(Y₂O₃）组成。另外，复合粉末中的Mo,O和Zr元素面扫描如图8(e～g）所示。可见，O和Zr元素（Y含量极少，难以检测）均匀地分布于Mo基体中。再结合图7(b）的EDS结果可知，这些复合粉末颗粒是由Mo,Zr O₂(Y₂O₃）组成。可见，Zr元素和Y元素分别是以氧化物Zr O₂和Y₂O₃的形式存在于Mo基体粉末中，且分布比较均匀。

图6 Mo O3粉体在不同温度下还原后粉末SEM照片

Fig.6 SEM images of Mo O₃powder prepared by reduction at different temperatures(a)350℃；（b)450℃；（c)550℃；（d)600℃；（e)650℃；（f)850℃

图7 Mo-Zr O2(Y2O3）复合粉末的FE-SEM图像和EDS能谱图

Fig.7 FE-SEM image and EDS spectrum of Mo-Zr O₂(Y₂O₃)composite powder(a)FESEM image;(b)EDS of Point A in Fig.7(a)

图8 Mo-Zr O2(Y2O3）复合粉末的TEM图像及衍射斑和元素面分布图

Fig.8 TEM image and diffraction spot,and element surface distribution of Mo-Zr O₂(Y₂O₃)composite powder

(a)TEM image;(b)Mo electron diffraction spot;(c)Mo-ZrO₂(Y₂O₃)electron diffraction spot;(d)TEM image and element distribution;(e)Mo map;(f)O map;(g)Zr map

3 结论

在400～650℃温度范围煅烧后的前驱体粉末物相都由氧化物Mo O₃组成，随着煅烧温度的不断升高，粉末形貌按薄片状-片层状-长棒状的规律演变。在保温3 h条件下时，Mo O₃还原成Mo的起始温度为550℃；如果采用一步还原的方法，煅烧产物Mo O₃完全转换为Mo的还原温度必须高于650℃。溶胶凝胶结合高温氢还原法能够制备出纳米级别且纯度较高的Mo-Zr O₂(Y₂O₃）复合粉末，团聚的复合粉末由80～100 nm粒径小颗粒组成，Zr O₂(Y₂O₃）均匀地分布在Mo基体粉末中。

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