The Effect of Ball Milling on Properties and Sintering of Nanostructured TiB2

2021 ◽  
Vol 21 (7) ◽  
pp. 3934-3937
Author(s):  
Seong-Eun Kim ◽  
In-Jin Shon

TiB2 powder was milled in a high-energy ball mill (Pulverisette-5 planetary mill) at 250 rpm for various time periods (0, 1, 4, and 10 h) and consolidated by the high frequency induction heated sintering (HFIHS). The effect of milling on the sintering behavior and crystallite size of TiB2 powders were investigated. A nanostructured dense TiB2 specimen with a relative density of up to 98% was readily achieved within very short time (two min). The ball milling effectively refined the crystallite structure of TiB2 powders and facilitated the subsequent consolidation. The sinter-onset temperature was reduced remarkably by the prior milling for 10 h. Accordingly, the relative density and mechanical properties of TiB2 compact increased as the milling time increased.

2014 ◽  
Vol 87 ◽  
pp. 157-161 ◽  
Author(s):  
Alfeu Saraiva Ramos ◽  
Marisa Aparecida de Souza ◽  
Roberto de Oliveira Magnago ◽  
Claudinei dos Santos ◽  
Camila Aparecida Araujo da Silva ◽  
...  

In this work, the preparation of Al2O3-TiO2 ceramics by high-energy ball milling varying the molar fraction in 1:1 and 3:1 was investigated. The powder mixtures were processed in a planetary mill at 250rpm and a ball-to-powder weight ratio of 5:1, for 120min. Compacts were obtained by cold pressing at 100MPa. These specimens were heated at 1000◦C for 30min to promote the water evaporation, and subsequently sintered at 1500◦C for 240min. Samples were characterized by relative density and X-ray diffraction. Hardness and fracture toughness were determined by Vickers Indentation Method. The crystallite sizes were lower than 420 and 560Å in Al2O3-TiO2 and 3Al2O3-TiO2 powders, respectively. After sintering, XRD analysis indicates Al2TiO5 and Al2O3/Al2TiO5 as major crystalline phases for Al2O3-TiO2 and 3Al2O3-TiO2 compositions, respectively. The relative density of the Al2O3-TiO2 ceramics was higher than 90% in both compositions. However, hardness and fracture toughness results of 10.7GPa or 10.5GPa and 3.2MPa.m1/2 or 2.6MPa.m1/2 for Al2O3-TiO2 and 3Al2O3-TiO2 mixtures respectively, indicates that microstructure duplex composed by Al2O3 and Al2TiO5 grains lead to improvement of toughness of these ceramics.


2006 ◽  
Vol 118 ◽  
pp. 661-665 ◽  
Author(s):  
Dae Hwan Kwon ◽  
Thuy Dang Nguyen ◽  
Pyuck Pa Choi ◽  
Ji Soon Kim ◽  
Young Soon Kwon

The microstructure and properties of Cu-TiB2 composites produced by high-energy ball-milling of TiB2 powders and spark-plasma sintering (SPS) were investigated. TiB2 powders were mechanically milled at a rotation speed of 1000rpm for short time in Ar atmosphere, using a planetary ball mill. To produce Cu-xTiB2 composites( x = 2.5, 5, 7.5 and 10wt.% ), the raw and milled TiB2 powders were mixed with Cu powders by means of a turbular mixer, respectively. Sintering of mixed powders was carried out in a SPS facility under vacuum. High-energy ball-milling resulted in refinement of TiB2 particles. XRD patterns of milled TiB2 powders indicated broader TiB2 peaks with decreased intensities. After sintering at 950 for 5min using the raw and milled TiB2 mixture powders, the sintered density decreased with increasing TiB2 content regardless of milling of TiB2. In the case of raw TiB2, hardness rapidly increased from 4 to 44 HRB with increasing TiB2 content. The electrical conductivity changed from 95.5 to 80.7 %IACS. For mixtures of Cu powders with milled TiB2 powders, hardness increased from 38 to 67 HRB as TiB2 content increased, while the electrical conductivity varied from 88% to 51 % IACS. When compared to compacts sintered with raw and milled TiB2 powders, the electrical conductivity of specimens with raw TiB2 powder was higher than that of specimens with milled TiB2 powder, while hardness was slightly lower.


2001 ◽  
Vol 16 (6) ◽  
pp. 1636-1643 ◽  
Author(s):  
L. B. Kong ◽  
J. Ma ◽  
T. S. Zhang ◽  
W. Zhu ◽  
O. K. Tan

Partially reacted mixtures of Pb(ZrxTi1−x)O3 and its corresponding starting oxide components were obtained by a high-energy ball milling process. The partially reacted powders were characterized by x-ray diffraction and scanning electron microscopy techniques. The sintering behavior of the milled mixtures has demonstrated a distinct volumetric expansion before the densification of the samples, which clearly shows the occurrence of a reactive sintering process of the partially reacted powders. Such process requires a lower densification temperature as compared with the PZT powders produced by the conventional solid-state reaction process. PZT ceramics were found to form directly from the partially reacted powders sintered at 900–1200 °C. The dielectric and ferroelectric properties of the PZT ceramics as a function of sintering temperature and milling time were also studied and discussed.


2007 ◽  
Vol 353-358 ◽  
pp. 1625-1628 ◽  
Author(s):  
Gen Shun Ji ◽  
Qin Ma ◽  
Tie Ming Guo ◽  
Qi Zhou ◽  
Jian Gang Jia ◽  
...  

The high energy ball milling of Ni-50 atom % Si elemental powder mixtures was carried out using a planetary mill. X-ray diffraction (XRD) was used to identify the phase evolutions during the high energy ball milling period. The microstructure morphology of the powders milled different time was determined by field emission scanning electron microscope (FESEM). The beginning time of mechanical alloying was determined by back scattered electrons (BSE) images. The XRD patterns showed that the nickel peaks intensity and the silicon peaks intensity obviously decreased with milling time increased to 1 hour. BSE images revealed that nickel and silicon powders were not blended uniformly for 1 hour of milling. It was found that NiSi formed as the milling time increased to 5 hours, simultaneously, the nickel peaks and the silicon peaks almost disappeared. That means the obvious mechanical alloying started from 5 hours of milling. BSE images agreed with the result analyzed from XRD patterns. With the milling time further increased from 10 to 75 hours, the NiSi peaks decreased gradually, at the same time, the Ni2Si peaks appeared and then increased gradually.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yuduo Ren ◽  
Shiting Zhang

Nano-TiC and nano-WC anodes for Li-ion battery were manufactured by high-energy ball milling. Pure titanium powder and toluene are mixed with a high-energy ball mill to prepare TiC powder. The powder is calcined at 750°C/1 h and secondary ball milled to make a negative electrode for lithium-ion battery. The phase composition and micromorphology of TiC powder are analyzed and observed, and the charge-discharge cycle performance of TiC anode material is tested. The results show that there are TiH2 and WC impurities in the product after primary ball milling. After calcination and secondary ball milling, TiH2 impurities are removed and the TiC grain size is refined, and TiC powder is obtained with a grain size of 12.5 nm. The specific discharge capacity of the TiC anode is stable during the long cycle discharge. When the current density is 1 A/g, the specific discharge capacity can still be maintained at 110 mAh/g after 3000 cycles. The results show that TiC anode materials have excellent long-cycle performance and could be used as the frame material of Si anode materials. Nano-WC powders are prepared by a ball milling method to investigate the effect of WC impurities on the performance of TiC lithium batteries. The charge and discharge capacity at 0.5 A/g current density is similar to that of TiC anode. After 2000 cycles, the discharge-specific capacity is about 100 mA/g, which is slightly lower than TiC, and the final capacity is maintained at 230 mA/g, but its low discharge capacity affects the performance of the TiC battery after a long ball milling. The results show that the performance of the TiC anode after the first 50 h of ball milling is poor. The main reason is the agglomeration of TiC nanoparticles.


2013 ◽  
Vol 20 (4) ◽  
pp. 275-279 ◽  
Author(s):  
Eun-Kwang Park ◽  
Sung-Mo Hong ◽  
Jin-Ju Park ◽  
Min-Ku Lee ◽  
Chang-Kyu Rhee ◽  
...  

2007 ◽  
Vol 33 (7) ◽  
pp. 1283-1286 ◽  
Author(s):  
Jae Shin Lee ◽  
Mun Seok Choi ◽  
Nguyen Viet Hung ◽  
Young Sun Kim ◽  
Ill Won Kim ◽  
...  

2020 ◽  
Vol 20 (7) ◽  
pp. 4253-4256
Author(s):  
Seong-Eun Kim ◽  
Jin-Kook Yoon ◽  
In-Jin Shon

Nb2O5 and Zr powders at a molar ratio of 1:2.5 were milled using a high-energy ball mill. The mixture powders produced Nb and ZrO2 nanopowders through a solid replacement reaction (Nb2O5+ 2.5Zr 2Nb + 2.5ZrO2). The synthesized nanopowders were consolidated via high-frequency induction heated sintering (HFIHS) within two min. The mechanical properties (hardness and fracture toughness) of nanostructured 2Nb–2.5ZrO2 composite were then evaluated. Both the hardness and fracture toughness of the 2Nb–2.5ZrO2 composite were higher than those of monolithic ZrO2.


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