Mechanical Properties and Microstructures of Severely Plastic Deformed Pure Titanium by Mechanical Milling and Spark Plasma Sintering
Mechanical Properties and Microstructures of Severely Plastic Deformed Pure Titanium by Mechanical Milling and Spark Plasma Sintering
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DOI：
10.4028/www.scientific.net/msf.667-669.559
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发表时间：
2010-12
期刊：
影响因子：
--
通讯作者：
M. Kubota;T. Ohno
中科院分区：
文献类型：
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作者：
M. Kubota;T. Ohno
为了提高纯钛的硬度和强度，采用机械球磨（MM）工艺，加入硬脂酸作为过程控制剂（PCA），利用振动球磨机对纯钛粉末进行剧烈塑性变形（SPD），然后利用放电等离子烧结（SPS）将具有大应变的MM粉末烧结成块体材料。通过显微硬度测量和X射线衍射研究了MMed粉末的硬度和组成相的变化。通过硬度测试和光学显微镜观察研究了SPS材料的硬度和显微组织。PCA为0.25 g的纯钛粉末经8 h的机械球磨（MM）处理后，其维氏显微硬度从189 HV急剧增加到513 HV。在MM过程的4和8小时期间，在MM ed粉末中发生作为固态反应产物的TiH2的形成。在49MPa的压力下，在1073K烧结0.5h，可获得接近全密度的SPS材料。由8 h MMed粉末与PCA 0.50 g制成的SPS材料的维氏硬度表现出最大值为1253 HV。
Severe plastic deformation (SPD) was applied to pure titanium powder by mechanical milling (MM) process with stearic acid, added as a process control agent (PCA), by using a vibrational ball mill, and MMed powders possessing large strains were subsequently consolidated into bulk materials by spark plasma sintering (SPS) in order to enhance the hardness and strength of pure titanium. Changes in the hardness and constituent phases of the MMed powders have been examined by microhardness measurements and X-ray diffraction. The hardness and microstructure of the SPS materials have also been studied by hardness measurements and optical microscopy. The Vickers microhardness of the pure titanium powders with PCA 0.25 g increased sharply from 189 HV to 513 HV after 8 h of the mechanical milling (MM) process. Formation of TiH2 as the solid-state reaction product occurred in the MMed powder during 4 and 8 h of the MM process. The near full density was obtained for the SPS materials under the condition of an applied pressure at 49 MPa with a sintering temperature at 1073 K for 0.5 h. The Vickers hardness of the SPS material fabricated from 8 h MMed powder with PCA 0.50 g exhibited a maximum value of 1253 HV.