別紙4 (課程博士)
Date of submlsslon

平成29年8月29日
Departnwnl. ofMedlanjcal

StudentlD Nunlber

Enginecl"ing

学籍番号SEIJIYOKOYA八仏
D149105
SupervisoTS

横山誠三

指導教員

MASANOBUIZAKI

PPI】ca11t'Snanle

伊崎昌伸
ABDULMUIZZBINMOHDNOORMASAHIROFUKUMOTO

氏名福本昌宏Abstract

論文内容の要旨(博士)PHYSICO・CHEMICALSTUDYOFCOPPER、CARBON SYSTEM FORPREPARATION
Iitle ofThesis
OFGRAPHITE DISPERSED COPPERALLOYCOMPOSITE

博士学位論文名(黒鉛分散銅基複合材料の開発に関する基礎研究)(APPI'O×.80o words)
Graphite・dispel'sed copper composites is known to have good lhem〕al and electrical conductivities,Selflubl、ication and low thennal expansion coef6Cient. These chal'actel'istic of it are derived from both
Characteristic ofcopper and gl'aphite. Thel'ef01'e, this composite is expected to be used for a slidino contact which anelectl'ic current aows in and 介iction acts on

First, a cu・Ni a110y in which the nickel was induded 11P to approximately 5 mass% was melted in a graphite
引'ucible 、vith a high fl'equency induction furnace t0 御'eP引'e the C11・Ni・csal (satⅢ'ated Cω'bon) aⅡoy. solubility ofC磁'bon into cu・Ni a110y incl'eased 、¥ith the nickel content and 、vith the melting temperatⅢ'e、 The pa11icles
Precipitated 介om the melt weTe graphite. The relation bet圦,een the activity coef負Cient of carbon for cu・Ni・C獣 andIhe tempel'ature could be expressed by numerical fomlulas. This w01'k proposed d]at the inteTaction pal'ameter,ωごifor cu・Ni、C釦1 、ヤas ・17.1. vickers hal'dness of cu・Ni・C師t system increased with c content. The cu・Ni・C訊l aⅡoy
Prepared in this study was hal'dened by pl、ecipitation hal'dening ofthe graphite particles and solution hal'dening ofNi

Second, solubility of nitl'ogen gas lnto pul'e copper at tempel'ature ral〕ge of 1993 K t0 2443 K 、¥as studied
W北h using a levitation melti】〕g apparatus. The solubility of nitrogen 圦,hich was equilibrated with nitrogen gas with aPI'essure of l01.3 kpa incl'eased with the temperature of lnolten copper. However, tl】e solubility 、¥as approximately
1.5 massppm even at 2443 K. The solubility obeyed the si飢モΠS'1a、Y. T11e relauon beハYeen the change of Gibbs

ena、gy f01' this l'eaction,△r6゜= 61573 + 48.75T and thel'modynalnic temP引'ature of the molten coppel',フ'[K],Was expl'essed as :1n[mass%N]

7406
75'863Th11'd, it was attempted that gl'aphite dispa'sed coppel' composite 、vas prepal'ed only on the suTface of aCoppa' plate using a spot welding maC11ine which could heat a matel'ial beyond 2073 K f01' sh011 time. EXP剖'iments
W引'e carried out with changing the compressive load, the repetition nulnber of the compression and the eleC廿ical

Cun'ent in 01'da' to study their effects on carbon content and vickel's hal'dness of ule composite. Gena'aⅡy, tl〕e
Carbon content ofthe composite pl'epared without an electrical cun'ent no、V 、vas smaⅡel' 1han that pl'epal'ed with aneleC廿ical cul'rent ao、V. The f0Πηer composite 、vas prepal'ed with that l'elatively sma11 anoular 01'aphite pa11icles、V剖'e pushed into the copP飢' plate. hlthe case of ao、ving electrical cul'1'ent, gl'aphite pa11icles 、¥as l】eated, andPa11ia11y or 、vh011y dissolved into molten coppel'. Thel'ef01'e,1his conlposile was pl'epal'ed with undissolved gl'aphileand pl'ecipitated 即'aphite froln the copper 111elt, The vickel's hal'dness of the coppel' matl'ix in 111e con〕posite
PI'epared without an electrical current ao、V 、vas larger than that pl'epal'ed wilh an electl、ical cul'「引〕t HO、V, becaLlse theelectl'ical heating annealed the composite. The relation between the vickel's hal'dness of t11e coppel・ ma11'ix in t11e
Composite and the volume 6'action ofgl'aphite were expl、essed by the l'L11e ofmixtul'es

FOU11h,1aS引' ilTadiation 、vas used to prepare the graP11ite dispel'sed coppel' composile on a coppel、 plate.'nw
Carbon dioxide laser was irradiated on t11e copper plate on which lhe gl'aphite pal'1ides 、vel'e plunged by r011ing
Most plunged pa11icles except t11e sma11 a1唱L11ar graP11ite pal'ticles whicl〕 wel'e stuck in 小e coppel' plale wel、eeli111inated, when the r011ed plate was dipped in the ultl'asonic bath. when the lasel'、vas il'1'adialed t0 小e l'0Ⅱed plale,
the number of 81'aphite pa11icles in t11e laser spot decreased with the lasel' in'adiation lime, because uw pal'ticles was
elh11inated by the laser tl'apping. HO、vevel', the fixing ofthe pa11icles l'esulted fl'onl i】〕]PI'OV引nent of 小e 、vettabilily
bet、veen the gl'aphite pal'ticle and lhe molten coppel"、入'hen the coppel' al'ound tl〕e gl'aphite pal'ticles fLn'thel' melted,
the pa11icles on the plate disappeared by the lasel' tl'apping. The numbel' of t11e graphile pal'1icles on 111e outside ofthe laS引、 spot incl、eased with time. The laser trapping hal'dly acted on uw 01'aphite pal、ticles at {his place. The coppel'
at the outside ofthe laser spot were heated by the conduction 6'om thc laS引' spot, and melted. The pal'ticles wcl'e
6Xed by the 、¥etting. The vickel's hardness decreased with an incl'ease with the lasel' il'radiation time due lo

annealing by the lasa' heat. The vickel's hardness at tl〕e outside ofthe lasel' spot was highel'than that at d]e centel' of
the lasa' spot

Fina11y, it was tl'ied to prepare the bulk of the graphite dispel'sed copper composite. The inauence ofthe t引11P引'ature, tl]e 、Nay of addition of the graphite pal'ticles and the a110ying elelnents (nickel, il'on)、ve】'eStudied. The glaphite pal'ticles were formed by t11e pl'ecipitation from the melt.＼Nhen u〕e temperalul'e wasabove approxhれately 2073 K, coppel' could 、vet to the gl'aphite, and this enhanced the dissolution of gl'aP11ite
into ule molten copper. Therefore, the composite pl'epared at 2073 K included more graphite particles thanthat a1 1673 K.1n addition, the colnposite prepal'ed by the addition of gl'aphite particles on the melt hold at2073 K C0川ained more graphite than the composite pTepared by the addition of theln bef01、e heatinσ. ThisルSulted from the quantity of sca杜el'ing gl'aP11ite 山lder l〕eating and the wettability. The gl'aphite pa杙icles in
the composite contained nicke11al'ger than that in P山'e copP引' because ule solubilily of carbon in
Coppel、・nickel system 、Nas lal'gel' than that in copper. The graphite particles in the composHe contained il'on、¥el'e smaⅡer ulan that in pul'e coppe↑, and mainly existed in iron lich phase. The >ickel's hωdness of theComposite aftel' annealing 、¥as smaⅡer than t11at befole annealing because of the relaxation of solid、S01{1tion

Strengthening of carbon. The hardness of the graphite dispersed coppel' a110y was largest due to theSolid・solution hal'd引ling ofthe a110ying elements