烧结温度对Ti-15Nb-25Zr-2Fe合金组织与力学性能的影响

采用放电等离子烧结技术制备Ti-15Nb-25Zr-2Fe钛合金,研究了烧结温度（800,1 000和1 200 ℃）对合金致密度、相组成、显微组织及力学性能的影响。结果表明：合金的致密度随烧结温度的升高逐渐升高。800 ℃烧结的样品主要由β相、α"相、α相和单质Zr组成。1 000 ℃和1200 ℃烧结的样品主要由β相和α"相组成,α"相含量随烧结温度的升高逐渐降低。三种温度烧结的样品中均观察到未固溶的Nb,其含量随烧结温度的升高逐渐降低。随着烧结温度的升高,合金的抗压强度逐渐升高,塑性先升高后降低。     

W-Ni-Fe高比重合金的SPS烧结行为

采用放电等离子烧结(SPS)设备制备了93W-5.6Ni-1.4Fe高比重合金,烧结温度范围为1 100～1 180 ℃,保温时间为5 min.对不同烧结温度下的样品进行了密度、硬度、抗弯强度等性能测试,采用场发射SEM观察了样品表面形貌及断裂行为.结果表明:采用SPS烧结,可以在较低的温度下实现93W-5.6Ni-1.4Fe高比重合金的固相烧结,使合金致密化,并能有效控制钨晶粒长大,提高材料的硬度、抗弯强度等力学性能.     

放电等离子烧结参数对 Al70Si30合金组织及性能的影响

探讨了放电等离子烧结（Spark Plasma Sintering ,SPS）技术对Al70 Si30合金中初晶硅分布、生长以及对其力学性能的影响。通过X射线衍射仪（XRD ）,扫描电子显微镜（SEM ）图谱分析发现,在500 M Pa ,590 K的烧结条件下,合金中的初晶硅尺寸保持在10μm左右。烧结后块体合金的维氏硬度达到190,致密度达到98．2％。     

不同温度下微波烧结Fe-Cu-C的性能

对微波烧结Fe-2Cu-0.6C粉末冶金材料进行探索性研究,研究不同烧结温度下微波烧结样品的性能和显微组织,并与相同温度下的常规烧结样品进行对比.研究结果表明:与常规烧结相比,微波烧结可得到较高的烧结密度以及较高的抗拉强度和伸长率,两者的洛氏硬度相当;微波烧结样品在1150℃时性能最佳,密度为7.20g/cm3,抗拉强度为413.90 MPa,洛氏硬度为HRB75;微波烧结样品具有良好的微观结构,即小的、近圆形且均匀分布的孔隙结构,从而也有利于获得细小的晶粒和较高的致密度;微波烧结与常规烧结相比,样品具有更多片状和粒状珠光体,能显著改善其性能.     

放电等离子烧结TiAl基合金的显微组织及力学性能

以Ti-47.5Al-2.5V-1.0Cr合金粉末为原料,采用放电等离子烧结工艺制备出TiAl基合金,并研究了制备工艺、显微组织与室温力学性能三者的关系.结果表明,采用放电等离子烧结方法可制备出致密度高、组织均匀的TiAl基合金.烧结温度对合金的显微组织影响显著,且其室温力学性能与显微组织密切相关,显微组织越细小,室温强度和塑性越高.当烧结温度为1100℃时,制备出的TiAl-V-Cr合金显微组织类型为细小双态组织,具有35.2%的压缩率和3321MPa的断裂强度,显示出较好的室温压缩性能.     

烧结压力对Al90Mn9Ce1合金SPS致密化的影响

采用放电等离子烧结（SPS）技术,在50MPa,300MPa,600MPa单轴压力下,对固结气雾化法制备的粒度为20-45μm的Al90Mn9Ce1合金粉末,研究了压力和脉冲电流作用下的致密化过程。结果表明,提高烧结压力有助于粉末的塑性变形和幂率蠕变,促进Al90Mn9Ce1合金压坯的致密化。当烧结压力为600MPa时,在660K保温0min条件下,样品致密度达到99．2％,强度达到1048．5MPa,原始颗粒之间形成宽度为20nm的熔合区,界面结合良好。     

SPS烧结温度对Ti2SnC导电陶瓷致密化的影响

机械合金化制备Ti2SnC粉体,采用放电等离子烧结（SPS）技术制备致密的Ti2SnC块体。研究烧结温度对机械活化SPS烧结Ti2SnC导电陶瓷块体致密化影响。结果表明,机械合金化合成Ti2SnC粉体经烧结后,气孔率随温度的升高逐渐降低。在900-1000℃之间进行SPS烧结可以获得纯度较高的块体。当温度在600-900℃范围内时,密度随烧结温度的提高而逐渐增大,当温度进一步提高时,则略呈下降趋势。     

钨合金力学性能及断口形貌的温度效应

研究了真空退火态93WNiFe合金在10-900℃的拉伸性能、断口形貌及显微组织,研究结果表明：随着温度的升高钨合金抗拉强度逐渐下降,延伸率先上升后下降,在400℃出现峰值,断口形貌由钨颗粒解理型断裂逐渐向钨颗粒与粘结相脱开型断裂转变,钨合金抗拉强度主要受断口断裂模式的影响,而延伸率却受钨颗粒和粘结相变形的共同影响。     

Microstructure,thermal properties,and corrosion behaviors of FeSiBAlNi alloy fabricated by mechanical alloying and spark plasma sintering

An equiatomic FeSiBAlNi amorphous high-entropy alloy (HEA) was fabricated by mechanical alloying (MA). A fully amorphous phase was obtained in the FeSiBAlNi HEA after 240 h of MA. The bulk FeSiBAlNi samples were sintered by spark plasma sintering (SPS) at 520 and 1080℃ under a pressure of 80 MPa. The sample sintered at 520℃ exhibited an amorphous composite structure comprising solid-solution phases (body-centered cubic (bcc) and face-centered cubic (fcc) phases). When the as-milled amorphous HEA was consolidated at 1080℃, another fcc phase appeared and the amorphous phase disappeared. The sample sintered by SPS at 1080℃ exhibited a slightly higher melting temperature compared with those of the as-milled alloy and the bulk sample sintered at 520℃. The corrosion behaviors of the as-sintered samples were investigated by potentiodynamic polarization measurements and immersion tests in seawater solution. The results showed that the HEA obtained by SPS at 1080℃ exhibited better corrosion resistance than that obtained by SPS at 520℃.     

放电等离子烧结制备Al-Zn-Mg-Cu纳米晶合金的组织

利用低温液氮球磨和放电等离子烧结工艺制备了块体纳米晶Al-Zn-Mg-Cu合金.采用X射线衍射(XRD)技术分析了材料的晶粒尺寸和微观应变,利用透射电镜(TEM)研究了合金微观组织的演变.结果表明:采用放电等离子烧结法制备的7000系纳米铝合金具有两种不同的纳米晶结构,以晶粒尺寸50～100nm的等轴晶为主,少量200～400nm的大晶粒为辅;烧结过程中发生再结晶及第二相析出,析出的第二相以η(MgZn2)为主,θ(Al2Cu)以及S(Al2CuMg))为辐.     

放电等离子烧结热变形Nd-Fe-B磁体的磁性能研究

采用放电等离子烧结技术,利用不同速率的快淬薄带制备出各向异性的热变形Nd-Fe-B磁体,运用振动样品磁强计和扫描电子显微镜对热变形磁体的磁性能和微观结构进行研究.结果表明：随着快淬薄带速率的增加,获得最佳磁性能的热变形温度也逐渐增加,三类热变形Nd-Fe-B磁体获得最佳磁性能的热变形温度分别为650,680和700°C;磁体最佳磁性能中的剩磁和最大磁能积随着快淬薄带速率的增加而降低,而内禀矫顽力却略有增加.磁体的晶粒尺寸随着热变形温度的增加而增大;相同热变形温度下,磁体的晶粒尺寸随快淬速率的增加而减小.     

Influence of sintering temperature on the thermoelectric properties of Ba8Ga16Si30 clathrate treated by spark plasma sintering

A series of Ba8Ga16Si30 clathrate samples were prepared by arc melting, ball milling, acid washing, and spark plasma sintering (SPS). X-ray diffraction analysis revealed that the lattice of the Ba8Ga16Si30 samples expanded as the SPS temperature was increased from 400 to 750°C. Lattice contraction recurred when the SPS temperature was further increased in the range of 750–1000°C. This phenomenon can be explained by the variation of Ga content in the lattice. The thermoelectric figure of the merit ZT value of clathrates increased with the increase in SPS temperature and reached a maximum when the sample was subjected to SPS at 800°C. A further increase in SPS temperature did not contribute to the improvement of ZT. The variation of the lattice parameter a vs. SPS temperature T was similar to the variation ob-served in the ZT–T curve.     

Graphene-reinforced aluminum matrix composites prepared by spark plasma sintering

Graphene-reinforced 7055 aluminum alloy composites with different contents of graphene were prepared by spark plasma sintering (SPS). The structure and mechanical properties of the composites were investigated. Testing results show that the hardness, compressive strength, and yield strength of the composites are improved with the addition of 1wt% graphene. A clean, strong interface is formed between the metal matrix and graphene via metallurgical bonding on atomic scale. Harmful aluminum carbide (Al₄C₃) is not formed during SPS processing. Further addition of graphene (above 1wt%) results in the deterioration in mechanical properties of the composites. The agglomeration of graphene plates is exacerbated with increasing graphene content, which is the main reason for this deterioration.     

Mechanical properties and friction behaviors of CNT/AlSi10Mg composites produced by spark plasma sintering

The mechanical properties and friction behaviors of CNT/AlSi10Mg composites produced by spark plasma sintering (SPS) were investigated.The results showed that the densities of the sintered composites gradually increased with increasing sintering temperature and that the highest microhardness and compressive strength were achieved in the specimen sintered at 450℃.CNTs dispersed uniformly in the AlSi10Mg matrix when the addition of CNTs was less than 1.5wt％.However,when the addition of CNTs exceeded 1.5wt％,the aggregation of CNTs was clearly observed.Moreover,the mechanical properties (including the densities,compressive strength,and microhardness) of the composites changed with CNT content and reached a maximum value when the CNT content was 1.5wt％.Meanwhile,the minimum average friction coefficient and wear rate of the CNT/AlSi10Mg composites were obtained with 1.0wt％ CNTs.     

放电等离子烧结制备超细WC-Co硬质合金

采用放电等离子烧结(SPS)技术制备了超细WC-10Co硬质合金.研究了烧结温度及烧结气氛对WC-Co硬质合金组织及性能的影响.研究发现:烧结体密度随烧结温度的升高而增大,但由于钴的蒸发,合金的成分偏离了原粉末的成分,且随着烧结温度的升高及炉内气压的降低,钴的蒸发速率加大.因此,通过提高炉内气压,可以使合金的成分基本接近原粉末成分,降低了合金的成分偏离.结果表明:炉内气压升高到200 Pa,烧结压力为30 MPa时,在1250℃烧结WC-10.07Co粉末5 min,烧结体中钴的质量分数可以控制在10.02%,密度和硬度分别达到了14.62 g.cm-3和HRA 92.4.     

机械合金化与等离子体烧结法制备CoSb3热电材料

研究用机械合金化及等离子体烧结法制备热电材料CoSb3化合物,试验结果表明,原始粉末机械合金化10h后,在500~600℃采用等离子体活化烧结能获得单相的CoSb3化合物,随烧结温度的升高,烧结样品密度增大,热导率随烧结温度的升高而降低。