論 文 日本大学生産工学部研究報告A 2006年12月第39巻第2号 メカニカルアロイング法と放電プラズマ焼結法で作製した アルミニウム-ホウ化物系複合材料の構成相と機械的強度特性 久保田正広 ・金子純一 ・菅又 信 Constituent Phases and M echanical Properties of Al - BorideCompositeM aterialsProduced by M echanically Alloyed and Spark Plasma Sintering Processes Masahiro KUBOTA, Junichi KANEKOand Makoto SUGAMATAAn air-atomized pure aluminium powder was mechanicallyalloyed (M A)with AlBor M gBbyusing a vibrational ball mill,and obtained MA powders were consolidated by spark plasma sintering (SPS). Solid-state reactions of MA powders have been examined by X-ray diffraction(XRD),and mechanical properties of the SPS materials have been evaluated byhardness measurements and compression tests. The solid-state reactions in both Al-AlBand Al-M gBsystems occurred between the M A powders and process control agent after heating at 573K to 873K for 24h.Formation ofAl BC ternarycompound occurred in both systems.After the heating,γ -Al O was formed in the Al-AlBsystem whereas MgAl O was formed in Al-M gBsystem.As theresult ofsolid-statereactions in both systems,hardening was observed in M A powders after heating at 573K to 873K for 24h.When 4h M A or 8hM A powders in both systems were spark plasma sintered byan applied pressure of 49M Pa at 873K for 1h,the full densityof the conpact was obtained.The compressive proof strength of the SPS material ofAl-M gBwas higher than that of Al-AlB. The SPS material of Al (MgB) from 8h M A powder exhibited the highest compressive proof strength of 846MPa at room temperature. Keywords: M echanical alloying, Spark plasma sintering, M echanical properties, X-ray diffraction, Nano-structured materials 1. 緒言 メカニカルアロイング (M echanical Alloying : M A) 法により,金属マトリックス中に種々のセラミックス粒 子を微細一に分散させ,常温および高温での強度向上 を図る研究が数多く行われてきた。これらの材料で は,セラミックス粒子がマトリックス中に微細一に分 散することで得られる分散強化,強加工によるマトリッ クスの加工硬化と結晶粒微細化による強化などが複合的 に寄与することで優れた機械的性質が導き出されてき た。 MA 法では材料設計の自由度が大きいことから,アル ミニウムに添加するセラミックス粒子は,けい化物,酸 化物,窒化物,炭化物およびほう化物など,いずれ も溶解鋳造法によるプロセスでは複合化が困難とされる 合金系がこれまで研究の対象とされてきた。MA 粉末を 固化成形する際の熱処理で,熱力学的に不安定なセラ ― ― 7 日本大学生産工学部機械工学科専任講師 日本大学生産工学部機械工学科教授
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
論 文 日本大学生産工学部研究報告A2006年 12月 第 39巻 第 2 号
メカニカルアロイング法と放電プラズマ焼結法で作製した
アルミニウム-ホウ化物系複合材料の構成相と機械的強度特性
久保田正広 ・金子純一 ・菅又 信
Constituent Phases and Mechanical Properties of Al-Boride Composite Materials Produced by
Mechanically Alloyed and Spark Plasma Sintering Processes
Masahiro KUBOTA , Junichi KANEKO and Makoto SUGAMATA
An air-atomized pure aluminium powder was mechanically alloyed(MA)with AlB or MgB by using
a vibrational ball mill,and obtained MA powders were consolidated by spark plasma sintering (SPS).
Solid-state reactions of MA powders have been examined by X-ray diffraction(XRD),and mechanical
properties of the SPS materials have been evaluated by hardness measurements and compression tests.
The solid-state reactions in both Al-AlB and Al-MgB systems occurred between the MA powders
and process control agent after heating at 573K to 873K for 24h.Formation of AlBC ternary compound
occurred in both systems.After the heating,γ-AlO was formed in the Al-AlB system whereas MgAl
O was formed in Al-MgB system.As the result of solid-state reactions in both systems,hardening was
observed in MA powders after heating at 573K to 873K for 24h.When 4h MA or 8hMA powders in both
systems were spark plasma sintered by an applied pressure of 49MPa at 873K for 1h,the full density of
the conpact was obtained.The compressive proof strength of the SPS material of Al-MgB was higher
than that of Al-AlB .The SPS material of Al (MgB ) from 8h MA powder exhibited the highest
compressive proof strength of 846MPa at room temperature.