(3.236.6.6) 您好!臺灣時間:2021/04/23 22:15
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果

詳目顯示:::

我願授權國圖
: 
twitterline
研究生:王聖棻
研究生(外文):Wang, Sheng-Fen
論文名稱:研磨處理對ZTA共沉粉末之影響研究
論文名稱(外文):A study on the effect of comminuting treatment of ZTA powders
指導教授:溫紹炳
指導教授(外文):Wang Shaw-Bing
學位類別:碩士
校院名稱:國立成功大學
系所名稱:資源工程學系
學門:工程學門
學類:材料工程學類
論文種類:學術論文
論文出版年:1996
畢業學年度:84
語文別:中文
論文頁數:61
中文關鍵詞:研磨機械化學晶種磨耗非晶質凝聚
外文關鍵詞:grindingmechanochemicalseedwearamorphousagglomerate
相關次數:
  • 被引用被引用:1
  • 點閱點閱:104
  • 評分評分:系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
本研究以研磨作業做為化學共沉法製備之 ZTA 陶瓷粉末之粉碎處理程序
。期望由研磨過程中,因研磨時的高壓作用使 ZTA 膠體粉末發生機械化
學反應、以及因撞擊、磨擦產生的能量儲存於膠體粉末中,經煆燒後促進
其相轉換成α - 氧化鋁; 同時經由α - 氧化鋁磨球所磨耗下來的磨屑
混入 ZTA 粉末中, 做為其後 ZTA 燒結時由θ - 氧化鋁轉變成α - 氧
化鋁之晶種。 以粉碎處理 ZTA 共沉粉末是利用不同能量的粉碎機械
( 轉磨機、振動磨機、 行星磨機 ) 處理共沉後的乾燥 ZTA 膠體粉末,
而由θ - 氧化鋁轉變成α - 氧化鋁之相變溫度、粉末性質與燒結晶相密
度來探討其影響。 研究發現:研磨處理會使 ZTA 共沉膠體產生相轉
換。 未經研磨處理的 ZTA 共沉膠中之氧化鋁呈 boehmite 及 bayerite
相, 經研磨處理後會使起始膠脫水變成以 boehmite為主相。 研磨能量
愈多會漸漸破壞粉末的 boehmite 結晶而生成非晶質相;而行星球磨處理
9.5 小時以上 ZTA 膠粉幾乎全為非晶質狀態。 ZTA 膠體粉末在熱處理的
過程中,有γ( η ) →δ ( θ ) →α -Al2O3 的相轉換產生,經研磨
處理後除結晶破壞以外,高能量的球磨會使氧化鋁之過渡相及 t-ZrO2 的
形成溫度提高, 且會減少相轉換中氧化鋁之過渡相,而由非晶質的膠粉
直接相轉換為δ ( θ ) →α -Al2O3,且其α -Al2O3 繞射峰強度隨著
研磨能量增加而變為較大,有良好的結晶性。 研磨處理後之 ZTA 共沉膠
其 BET 值明顯地下降,此乃膠體乾磨後促使粉粒間互相凝聚的現象,煆
燒後 BET 值則未受到粉碎能量的影響。 而行星球磨後的樣品有相轉換及
再分散凝聚的現象。經過氧化鋁球振動球磨氧化鋁球 24 小時、行星球磨
1.5 小時即能使 (( α -Al2O3 之相轉換溫度提前在 1100 ℃,而轉動球
磨 12 小時後能降低α -Al2O3 之相轉換溫度於 1200 ℃出現, 此結果
顯示粉碎能量密度較大之行星球磨確實能縮短研磨時間而促進 (( α
-Al2O3 之相轉換。 且研磨作用時所產生的能量因素及磨耗產生的磨屑皆
是影響 (( α -Al2O3 之相轉換的原因。 研磨處理後之 ZTA 膠體粉末經
煆燒及成形後,以 1550 ℃持溫 4 小時條件下進行燒結, 經由氧化鋁球
振動球磨 24 小時以上, 氧化鋯球振動球磨 24 小時以上可得到 99.5
﹪之緻密ZTA 燒結體,其氧化鋁及氧化鋯之結晶分佈有類似氧化鋯韌化氧
化鋁之形態。
A study on the effect of comminuting treatment of ZTA Powders
The treatment of ZTA( zirconia toughened alumina) ceramic
powders bycomminuting operations during manufacturing process is
the scope of this study.The raw material of ZTA powders is
prepared by chemical coprecipitation via-gel method. Before
calcination, ZTA powders are comminuted by tumbling mill,
vibration mill and planetary mill. The energy accumulated from
the impact andattrition actions of comminuting ZTA gel
powders to occur mechano- chemicalreaction and enhance the
sintering body. Meant me, The chips loosening fromalumina
grinding ball will become the nucleating seeds during sintering
of ZTAceramic of ZTA powders. In this study, the dry
coprecipitation gel are treated by vibrationmill and tumbling
ball mill with different grinding duration. The alumina
andzirconia grinding balls are adopted for comminution tests.
The wear of grindingball and the chips loosening from ball
surface are examined during everycomminution test. The function
of comminution treatment is evaluated by thespecific surface
area phase transformation and sintering density of finalceramic
products.The results of this study are listed as following: 1.
We discover the comminuted ZTA gel can produce mechano-chemical
reaction.The predominant phase observed in the ZTA gels are
boehmite and bayerite. Thecomminuted treatment can make ZTA
gel dehydroxyation and transformation toboehmite phase.
However, Planetary ball milling above 9.5hrs can make ZTA
gelamorphous. 2. ZTA gel powder has the phase transformation
of γ ( η ) →δ ( θ ) →α-Al2O3 during annealing treatment.
Large comminuted energy can make its crystaldestructive and
amorphous. Except the the destruction of crystal by
comminutedtreatment, high energy ball milling can prolong the
forming temperature ofmetastable phase of Al2O3 and t-ZrO2,
reduce the content metastable phase ofAl2O3,and directly
transform δ ( θ ) →α -Al2O3. The intensity of α -Al2O3is
intensive with perfect crystal. 3. BET surface area of ZTA gel
markly decreases after comminuted treatment.This phenomemon
is the result that ZTA particle aggregated each other,
BETsurface area of calcined powders are not affected.
After planetary ballmilling, has occur phase transformationand
re-dispersed, agglomerate. 4. ZTA powders with tumbling ball
milling of 12 hours duration can reduce thephase transformation
of θ -Al2O3 to α -Al2O3 to 1200 ℃. Vibrating ballmilling
of 24 hours duration and planetary ball milling 1.5 hours
duration canmake it reduce to 1100 ℃. This result appears that
planetary ball milling ofhiger comminution energy can
shorten the grinding time to cause thetransformation of
θ→α -Al2O3. However, both the energy and chips seeding
inmilling process are the main reason of affecting the transform
ation of θ→α-Al2O3. 5. The vibrating ball milling with
Al2O3 balls above 24 hrs and with ZrO2balls above 34 hrs of
the ZTA ceramic body which sintering at 1550 ℃ with 4hour
duration can obtain the relative density of final ceramic body
is measuredof 99.5 % T.D.
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top
系統版面圖檔 系統版面圖檔