Consolidation of Hard Sinterable Materials and Near Net Shape Forming by Pulsed Current Pressure Sintering (PCPS) Process.

通过脉冲电流压力烧结 (PCPS) 工艺固结硬质可烧结材料并实现近净形状成型。

基本信息

批准号：
13555203
负责人：
YOKOTA Masaru
金额：
$ 6.98万
依托单位：
Takaoka National College
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

The Pulsed Current Pressure Sintering (PCPS) is well known as rapid sintering process. This is a kind of hot pressing which employs the pulsed electric current to heat materials. It is suggested to be characterized by four major advantages over the conventional consolidation techniques, i.e. : (1) preservation of original microstructures after consolidation, (2) high density consolidation in a short time, (3) removal of adsorbed materials on the powder surface, (4) improved mechanical properties resulted from these (1)-(3) items. We employed the PCPS process to consolidate the aluminum alloy powder and attained the high strength sintered specimen. Furthermore, hollow shaped compacts and functionally graded Al/Al2O3 materials were formed by PCPS. Principal results obtained are as follows :(1) The maximum tensile strength of PCP sintered compact was over 9OMPa and the elongation was 50%. This value outweigh that of 1000 series Al wrought alloys.(2) PCP sintering process can densify Al powders in a short time compared to the HP sintering process. Mechanical properties of the compacts outweigh the HP compact.(3) The hollow compacts having an intricate shape were obtained by a one-pass process of PCPS sintering using the core made of h-BN or graphite powders because of their good compactibility and difficultly sinterable properties.(4) The Al/Al_2O_3 FGM composed of a dense a-Al_2O_3 layer and seven gradient intermediate layers was successfully fabricated from starting materials consisting of aluminum and Al(OH)_3 powders by employing a temperature gradient PSPC process with a copper spacer, at a pressure of 49 MPa, and with the short sintering time of 900 sec. The hardness of the aluminum layer was about 25 HV. The hardness of intermediate layers gradually increased as the volume fraction of r-Al_2O_3 increased. The top layer, which consists of dense a-Al_2O_3, was about 1000 HV on average, and the top surface of the specimen reached 1500 HV.

脉冲电流压力烧结（PCP）被称为快速烧结过程。这是一种使用脉冲电流来加热材料的热压力。建议的特征是与传统固结技术相比，即：（1）固结后的原始微观结构保存，（2）在短时间内高密度固结，（（3）去除粉末表面上的吸附材料，（（4）从这些（4）从这些（4）从这些（1）（1）（3）项目产生的改进的机械性能。我们采用了PCP工艺来合并铝合金粉末，并获得了高强度烧结的样品。此外，由PCP形成了空心形状的紧凑型和功能分级的Al/Al2O3材料。获得的主要结果如下：（1）PCP烧结紧凑型的最大拉伸强度超过9OMPA，伸长率为50％。该值大于1000系列Al锻造合金的值。（2）与HP烧结过程相比，PCP烧结过程可以在短时间内在短时间内致密。紧凑型的机械性能大于HP的紧凑型。（3）具有复杂形状的空心紧凑型通过使用H-BN或石墨粉制成的核心烧结的一部分PCP烧结而获得，因为它们具有良好的紧凑性，并且由于它们具有良好的可杀伤性和难以烧结的特性。通过使用铜垫片的温度梯度PSPC工艺，以49 MPa的压力和900秒的短烧结时间使用温度梯度PSPC工艺，成功地从铝和Al（OH）_3粉末组成的起始材料中成功制造。铝层的硬度约为25 hv。随着R-AL_2O_3的体积分数增加，中间层的硬度逐渐增加。由密集A-AL_2O_3组成的顶层平均约为1000 hv，样品的顶表面达到1500 HV。