Diffusion Rift · AEML, NTUST · CT3309301
無敵Immune
交換位置!Site swap!
晶界捷徑(最快)Grain-Boundary Path (fastest)
空位之路Vacancy Path
間隙之路Interstitial Path
萬物晶格之中,原子從不靜止。Within every crystal, atoms are never still.
晶格同盟守護著湛藍的晶都——他們的溶質,從高濃度流向低濃度。The Crystal Concord guards the sapphire citadel; its solute flows from high concentration to low.
熔爐軍團點燃了深紅要塞,要以烈焰與時間,滲透整個大陸。The Furnace Legion has lit the crimson fortress, to soak the whole continent with heat and time.
三條路徑通往敵陣:晶界捷徑、空位之路、間隙之路——每條的擴散係數 D 都不同。Three paths lead to the enemy: grain boundary, vacancy and interstitial, each with its own diffusion coefficient D.
梯度推動通量,溫度喚醒原子,深度隨時間的平方根成長。Gradients drive flux. Heat wakes the atoms. Depth grows with the square root of time.
召喚師,擴散之戰即將開始。Summoner, the war of diffusion begins.
法師Mage
刺客Assassin
輔助Support
射手Marksman
坦克Tank
控制Controller
菲克Fick
梯度賢者The Gradient Sage
「濃度差,就是我的力量。」"Every gradient is a source of power."
以菲克定律作戰的法師。目標所在處的濃度梯度越陡,她的法術越強。A mage who fights with Fick's laws: the steeper the concentration gradient at the target, the stronger her spells.
梯度衝擊Gradient Bolt
射出光彈;命中處的 |∇C| 越大,傷害最多 +90%。A bolt whose damage rises up to +90% with |∇C| where it hits.
通量領域Flux Field
4 秒領域:持續注入我方溶質,緩速並傷害敵人。A 4 s field that pumps in friendly solute, slowing and damaging enemies.
穩態光束(大招)Steady-State Beam (Ult)
蓄力後射出長光束,沿線留下由高到低的線性濃度剖面。After a short charge, a long beam leaves a linear concentration profile along its path.
菲克第一定律 J = −D dC/dx:梯度越陡,通量越大——傷害也越高。Fick's 1st law, J = −D dC/dx: steeper gradient, larger flux, more damage.
持續注入溶質=固定的表面濃度 Cs,溶質會沿梯度向外擴散。Constant injection acts like a fixed surface concentration Cs; solute spreads down the gradient.
穩態擴散:通量不隨時間改變,濃度剖面呈直線。Steady-state diffusion: flux is constant in time and the profile is a straight line.
布朗Brown
隨機漫步者The Random Walker
「沒有人指揮我,但我總會抵達。」"No one steers me, yet I always arrive."
以隨機跳躍切入戰場的刺客,象徵擴散的微觀本質——原子的隨機漫步。An assassin who leaps in random hops, the microscopic picture of diffusion: a random walk.
隨機漫步Random Walk
連續三次方向隨機(偏向瞄準方向)的跳躍,每次落地造成傷害。Three hops in random directions (biased toward your aim); each landing deals damage.
熱振動Thermal Jitter
2.6 秒內移速 +45%、受到傷害 −30%。For 2.6 s: +45% move speed and 30% less damage taken.
布朗風暴(大招)Brownian Storm (Ult)
3 秒內在自身周圍隨機落下連續打擊。For 3 s, strikes rain down at random points around you.
隨機漫步 n 步,淨位移約 √n × 步長,而不是 n × 步長。After n random steps the net displacement is about √n steps, not n.
溫度越高,原子振動越劇烈,越容易越過能障跳到鄰位。Hotter atoms vibrate harder and hop over the energy barrier more often.
沒有誰在「推」原子:淨通量來自大量隨機跳躍的統計結果。Nothing pushes the atoms: net flux is the statistics of countless random jumps.
阿瑞尼斯Arrhenius
熔爐守護者Keeper of the Furnace
「溫度升高一點,世界就快上許多。」"Raise the heat a little, and the world moves much faster."
掌控溫度的輔助。她能改變地圖局部溫度,讓擴散係數依阿瑞尼斯方程式指數成長。A support who controls temperature, making D grow exponentially by the Arrhenius equation.
活化火焰Activation Flame
火球爆炸,灼燒敵人並使該處升溫。A fireball that burns enemies and heats the ground.
升溫領域Heat Zone
5 秒領域:區內 D 暴增;隊友攻速、移速提高並持續回血。A 5 s zone: D soars inside; allies gain attack speed, move speed and healing.
熔爐之陽(大招)Furnace Sun (Ult)
治療周圍隊友、灼燒敵人,並使大範圍高溫。Heals nearby allies, burns enemies and heats a wide area.
溫度是擴散的關鍵變數:觀察火球落點,濃度場擴散明顯變快。Temperature is the key variable: watch the field spread faster where the fireball lands.
D = D₀ exp(−Qd/RT):T 一升高,D 呈指數成長。D = D₀ exp(−Qd/RT): raise T and D grows exponentially.
ln D 對 1/T 作圖是直線,斜率 = −Qd/R。ln D vs 1/T is a straight line with slope −Qd/R.
小碳Carbon
間隙遊俠The Interstitial Ranger
「個子小,跑得快!」"Small atom, fast feet!"
嬌小的碳原子射手,在大原子的縫隙間穿梭——間隙擴散比空位擴散快得多。被動:移速提高。A tiny carbon marksman slipping between big atoms: interstitial diffusion is much faster than vacancy diffusion. Passive: extra move speed.
間隙穿梭Interstitial Dash
向前穿越,下一次普攻傷害 +60%。Dash forward; your next basic attack deals +60%.
滲碳箭Carburize Arrow
長距離箭矢:標記目標 5 秒(受傷 +20%),並在命中處注入溶質。A long arrow that marks the target for 5 s (+20% damage taken) and injects solute.
表面硬化(大招)Case Hardening (Ult)
6 秒內攻速 +50%、獲得護盾、普攻濺射。For 6 s: +50% attack speed, a shield and splashing attacks.
間隙擴散:小原子(C、N、H、O)在間隙位置跳躍,鄰近空位多、速度快。Interstitial diffusion: small atoms (C, N, H, O) hop between interstitial sites, which are plentiful, so it is fast.
滲碳:在高溫富碳氣氛中,碳擴散進鋼的表層。Carburizing: at high temperature in a carbon-rich atmosphere, carbon diffuses into the steel surface.
表面硬化:表層含碳量高而變硬,提升耐磨與抗疲勞。Case hardening: the carbon-rich surface layer becomes hard, resisting wear and fatigue.
空位騎士Vacancy
虛空守衛The Hollow Guardian
「總得有人讓位,原子才能前進。」"Someone must step aside for atoms to move."
盾牌中央是一個空位的坦克。空位擴散需要:鄰位有空位,以及足以越過能障的能量。A tank whose shield holds a vacancy. Vacancy diffusion needs an empty neighbouring site and enough energy to cross the barrier.
位置交換Site Swap
衝向目標並與其交換位置,造成傷害與 0.8 秒暈眩。Dash to a target and swap places with it, dealing damage and a 0.8 s stun.
空位之盾Vacancy Shield
4 秒護盾,附近隊友獲得一半。A 4 s shield; nearby allies get half.
晶格崩塌(大招)Lattice Collapse (Ult)
0.4 秒後震盪周圍,暈眩 1.3 秒並造成傷害。After 0.4 s, a shockwave stuns nearby enemies for 1.3 s.
空位機制:原子與相鄰空位交換位置——原子往一邊走,空位就往另一邊走。Vacancy mechanism: an atom swaps with a neighbouring vacancy; atoms and vacancies move in opposite directions.
自擴散與互擴散多以空位機制進行;空位數量隨溫度升高而增加。Self- and interdiffusion usually go by vacancies; the number of vacancies rises with temperature.
空位擴散的活化能包含形成空位與移動原子兩部分,通常比間隙擴散高。Vacancy diffusion's activation energy covers forming and moving a vacancy, so it is usually higher than interstitial.
時之主Chronos
時間平方根之主Lord of the Square Root of Time
「深度與時間的平方根成正比。耐心,也是一種力量。」"Depth grows with the square root of time. Patience is power."
掌握非穩態擴散與誤差函數解的控制型英雄。A controller who wields non-steady-state diffusion and the error-function solution.
誤差函數波Erf Wave
扇形衝擊,傷害依 1 − erf(x/L) 隨距離遞減。A cone blast whose damage falls off with distance as 1 − erf(x/L).
時間膨脹Time Dilation
3 秒強力緩速領域。A 3 s heavy slow zone.
√t 擴張(大招)√t Expansion (Ult)
環狀衝擊波以 r = k√t 向外擴張:越到外圍越慢。A ring expands as r = k√t, slowing as it grows.
(Cx−C₀)/(Cs−C₀) = 1 − erf(x / 2√(Dt)):離表面越遠,濃度越低。(Cx−C₀)/(Cs−C₀) = 1 − erf(x / 2√(Dt)): the farther from the surface, the lower the concentration.
要得到相同的擴散效果,只要 Dt 相同:D 變小,就得等更久。The same diffusion result needs the same Dt: smaller D means waiting longer.
擴散深度 x ∝ √(Dt):深度加倍,時間要四倍!Depth x ∝ √(Dt): to double the depth, wait four times as long!
提示:地面的藍紅色是即時計算的溶質濃度場 C(x,y,t)。站在我方溶質中會加速並回血。Tip: the blue and red tint is the live solute field C(x,y,t). Standing in your own solute speeds you up and heals you.
∇
⦿
☲
⤨
≋
✺
🔥
♨
☀
➹
➶
⛨
⇄
⛉
✷
⌇
⧗
√
間隙之靴Interstitial Boots
+45 移速+45 move speed
👢
沃斯田鐵之刃Austenite Blade
+24 攻擊+24 attack
🗡
晶界典籍Grain-Boundary Tome
+22% 技能強度+22% skill power
📘
空位鎧甲Vacancy Plate
+260 生命、+14 護甲+260 HP, +14 armor
🛡
熔爐核心Furnace Core
−15% 冷卻、+120 生命−15% cooldown, +120 HP
⚙
滲碳硬化盾Case-Hardened Aegis
+420 生命、+22 護甲、+8% 技能+420 HP, +22 armor, +8% skill
🔰
誤差函數長弓Erf Longbow
+22% 攻速、+12 攻擊+22% attack speed, +12 attack
🏹
活化能藥劑Activation Elixir
+18 攻擊、+12% 技能、10% 吸血+18 attack, +12% skill, 10% lifesteal
⚗
歡迎來到擴散戰線Welcome to the Diffusion Rift
原子兵團出發!Atomlings march!
擊敗敵方英雄!You slew an enemy!
你已陣亡You have been slain
我方英雄陣亡An ally has fallen
敵方英雄陣亡An enemy has fallen
摧毀敵方防禦塔!Enemy tower destroyed!
我方防禦塔被摧毀Our tower has fallen
獲得「通量」增益:冷卻加速Flux buff: faster cooldowns
獲得「熾熱」增益:普攻灼燒Heat buff: attacks burn
我方擊敗活化能巨龍!全隊強化We slew the Activation Dragon! Team empowered
敵方擊敗了活化能巨龍The enemy slew the Activation Dragon
我方擊敗平衡魔像!兵線強化We felled the Equilibrium Golem! Waves empowered
敵方擊敗了平衡魔像The enemy felled the Equilibrium Golem
活化能巨龍已出現The Activation Dragon has appeared
平衡魔像已出現The Equilibrium Golem has appeared
等級 4:答對研究題即可解鎖大招Level 4: answer a research question to unlock your ultimate
我方溶質:加速+回血Own solute: faster + regen
敵方溶質:減速Enemy solute: slowed
混合區Mixed zone
⦿ 通量Flux
♨ 熾熱Heat
🐉 巨龍之力Dragon might
⛰ 兵線強化Wave surge
簡單Easy
普通Normal
困難Hard
上Up
下Down
左Left
右Right
普攻(按住)Attack (hold)
技能 1Skill 1
技能 2Skill 2
大招Ultimate
回城Recall
實驗室/商店Lab / shop
戰況(按住)Scoreboard (hold)
暫停Pause
全螢幕Fullscreen
存檔檔案無效。That save file isn't valid.
變更Change
已複製連結Link copied
電腦CPU
(空)(empty)
硬體加速運作中Hardware acceleration on
此裝置無法使用硬體加速,已改用軟體繪圖Hardware acceleration unavailable; using software
軟體繪圖Software rendering
房主Host
{p} 加入了房間{p} joined
手機提示:可在設定開啟「螢幕搖桿」;也可直接點地面移動、點敵人攻擊。Tip: turn on the on-screen stick in Settings, or tap the ground to move and tap enemies to attack.
勝Win
敗Loss
有玩家離線,暫由電腦代打A player disconnected; the CPU takes over
已讀取存檔Game loaded
讀取中…Loading…
大招尚未解鎖:升到 4 級並答對研究題Ultimate locked: reach level 4 and answer a research question
房主已離線The host went offline
目前還沒有紀錄No scores yet
尚未設定全球排行榜網址(設定 → 排行榜網址)No global leaderboard URL yet (Settings → Leaderboard URL)
目前沒有進行中的戰局No match in progress
連線對戰中無法存檔Online matches can't be saved
此欄位沒有存檔No save in that slot
瀏覽器空間不足,請改用匯出Browser storage is full; use Export
線上玩家Online
冷卻中,請稍後再試Cooling down, try again soon
已存檔Saved
已記錄在本機排行榜Saved to this device's leaderboard
賣出Sell
無法連線到全球排行榜(已記錄在本機)Couldn't reach the global leaderboard (kept on this device)
已送出到全球排行榜Sent to the global leaderboard
回到我方主堡附近(或陣亡時)才能購買裝備;答題隨時可進行。Return to your base (or wait while dead) to buy items; questions can be answered anytime.
位於主堡,可以購買裝備。You're at base and can buy items.
等待玩家…Waiting…
你You
晶格同盟Crystal Concord
熔爐軍團Furnace Legion
普攻優先鎖定英雄Attacks prefer heroes
普攻攻擊最近目標Attacks hit the nearest target
★ 大招研究:答對即可解鎖終極技能★ Ultimate research: answer correctly to unlock your ultimate
研究補助考驗:答對 +130 金Research grant: +130 gold if correct
答對了!Correct!
答錯了。Not quite.
大招已解鎖!Ultimate unlocked!
獲得 130 金!+130 gold!
大招解鎖!Ultimate unlocked!
勝利VICTORY
失敗DEFEAT
連線中…Connecting…
房間 {n} 已開啟,等待玩家Room {n} open, waiting for players
已連上中繼,等待房主…Connected; waiting for the host…
連線中斷,重新連線…Connection lost, retrying…
無法連到中繼伺服器Couldn't reach the relay
已加入房間,等待房主出征Joined; waiting for the host to start
房間已滿或已開戰Room full or already started
房號是 6 碼英數字Room codes have 6 letters/digits
「擴散 (diffusion)」最精確的定義是?Which best defines diffusion?
- 液體因重力流動Liquid flowing under gravity
- 物質藉由原子運動而進行的質量傳輸Mass transport by atomic motion
- 電子在導體中的移動Electron flow in a conductor
- 晶粒在加熱時長大Grain growth on heating
擴散是藉由原子運動造成的質量傳輸,在固體中也會發生。Diffusion is mass transport by atomic motion, and it happens in solids too.
把銅塊與鎳塊緊密接合後長時間加熱,兩種原子互相跨越界面擴散,這稱為?A Cu block and a Ni block are joined and heated for a long time; atoms of each cross the interface. This is called:
- 自擴散Self-diffusion
- 再結晶Recrystallization
- 互擴散(雜質擴散)Interdiffusion (impurity diffusion)
- 析出硬化Precipitation hardening
兩種金屬原子由高濃度往低濃度互相擴散,稱為互擴散。Atoms of two metals move from high to low concentration into each other: interdiffusion.
純金屬中,同種原子彼此交換位置的擴散稱為?In a pure metal, diffusion of host atoms among themselves is called:
- 自擴散Self-diffusion
- 互擴散Interdiffusion
- 間隙擴散Interstitial diffusion
- 穩態擴散Steady-state diffusion
純金屬中同種原子的遷移稱為自擴散,因成分不變,常以放射性同位素追蹤。Host atoms migrating in a pure metal is self-diffusion; composition doesn't change, so radioactive tracers are used to follow it.
原子要藉空位機制跳到鄰位,必須具備哪兩個條件?For an atom to move by the vacancy mechanism, which two conditions are needed?
- 外加電場與磁場An electric and a magnetic field
- 高壓與液態High pressure and a liquid state
- 晶界與差排A grain boundary and a dislocation
- 鄰近有空位,且原子有足夠能量越過能障An adjacent empty site and enough energy to break bonds and squeeze past
兩個條件:(1) 相鄰位置是空的;(2) 原子有足夠的振動能量打斷鍵結、擠過鄰原子。Two conditions: (1) an empty adjacent site; (2) enough vibrational energy to break bonds and distort the lattice while moving.
在多數金屬中,間隙擴散比空位擴散快得多,主要原因是?Interstitial diffusion is usually much faster than vacancy diffusion because:
- 間隙原子比較重Interstitial atoms are heavier
- 間隙原子較小、可移動的鄰近間隙位置遠多於空位Interstitial atoms are smaller and empty interstitial sites far outnumber vacancies
- 間隙擴散不需要能量Interstitial diffusion needs no energy
- 間隙原子帶電Interstitial atoms are charged
小原子活動性高,而且鄰近的空間隙位置比空位多得多,所以跳躍機率高。Small atoms are more mobile, and there are many more empty interstitial positions than vacancies.
下列哪一組最常以「間隙擴散」在金屬中移動?Which atoms most commonly diffuse interstitially in metals?
- H、C、N、OH, C, N, O
- Cu、Ni、ZnCu, Ni, Zn
- Fe、Cr、MoFe, Cr, Mo
- Au、Ag、PtAu, Ag, Pt
原子半徑小的雜質(氫、碳、氮、氧)能塞進主原子之間的間隙。Small impurity atoms (hydrogen, carbon, nitrogen, oxygen) fit into the interstices between host atoms.
「滲碳 (carburizing)」表面硬化的原理是?Case hardening by carburizing works by:
- 在室溫下以鎚擊表面Hammering the surface at room temperature
- 讓鋼表面的碳往外擴散Letting carbon diffuse out of the steel
- 高溫下讓碳從富碳氣氛擴散進鋼的表層Diffusing carbon from a carbon-rich atmosphere into the steel surface at high temperature
- 把鋼急冷到液態氮溫度Quenching the steel in liquid nitrogen
滲碳在高溫進行,碳原子擴散入表層,提高表面含碳量與硬度、耐磨與抗疲勞性。At high temperature carbon diffuses into the surface layer, raising its carbon content, hardness, wear and fatigue resistance.
擴散通量 J 的 SI 單位是?The SI unit of diffusion flux J is:
- m²/sm²/s
- kg/m³kg/m³
- J/molJ/mol
- kg/(m²·s) 或 atoms/(m²·s)kg/(m²·s) or atoms/(m²·s)
通量=單位時間通過單位截面積的質量(或原子數),J = M/(At)。m²/s 是擴散係數 D 的單位。Flux is mass (or atoms) per unit area per unit time, J = M/(At). m²/s is the unit of D.
菲克第一定律 J = −D dC/dx 中的負號表示?In Fick's first law J = −D dC/dx, the minus sign means:
- D 一定是負值D is always negative
- 擴散方向是沿濃度梯度向下,由高濃度往低濃度Diffusion goes down the gradient, from high to low concentration
- 通量隨時間遞減Flux decreases with time
- 只適用於負離子It applies only to anions
負號代表擴散方向與濃度梯度相反:往濃度低的方向走。The sign shows diffusion opposes the gradient: it goes toward lower concentration.
「穩態擴散」的特徵是?Steady-state diffusion is characterized by:
- 通量不隨時間改變;D 為定值時濃度剖面為直線Flux doesn't change with time; with constant D the profile is linear
- 濃度處處相同Uniform concentration everywhere
- 通量隨時間指數遞增Flux growing exponentially with time
- 只發生在液體中It occurs only in liquids
穩態時 J 與時間無關;若 D 不隨濃度改變,C(x) 是一條直線,斜率即濃度梯度。At steady state J is time-independent; if D is constant, C(x) is a straight line whose slope is the gradient.
例題 5.1:鐵片兩側分別滲碳與脫碳達穩態,5 mm 與 10 mm 處碳濃度為 1.2 與 0.8 kg/m³,D = 3×10⁻¹¹ m²/s。擴散通量 J 為?Ex. 5.1: steady state, C = 1.2 and 0.8 kg/m³ at 5 mm and 10 mm, D = 3×10⁻¹¹ m²/s. The flux J is:
- 2.4 × 10⁻⁹ kg/(m²·s)
- 2.4 × 10⁻⁶ kg/(m²·s)
- 1.2 × 10⁻⁹ kg/(m²·s)
- 6.0 × 10⁻¹² kg/(m²·s)
J = −D(C₂−C₁)/(x₂−x₁) = −(3×10⁻¹¹)(0.8−1.2)/(0.005) = 2.4×10⁻⁹ kg/(m²·s)。記得 mm 要換成 m!J = −D(C₂−C₁)/(x₂−x₁) = −(3×10⁻¹¹)(0.8−1.2)/(0.005) = 2.4×10⁻⁹ kg/(m²·s). Convert mm to m first!
兩處的 D 相同,A 處濃度梯度是 B 處的 3 倍。A 處的通量是 B 處的?D is the same at two places, but the gradient at A is 3× that at B. The flux at A is:
- 1/3 倍1/3 as large
- √3 倍√3 times
- 3 倍3 times
- 9 倍9 times
J 與 dC/dx 成正比,梯度 3 倍,通量就 3 倍——菲克英雄的「梯度衝擊」就是這樣算傷害的。J is proportional to dC/dx, so 3× the gradient gives 3× the flux, just like Fick's Gradient Bolt.
菲克第二定律(D 為常數)是?Fick's second law (constant D) is:
- J = −D dC/dxJ = −D dC/dx
- ∂C/∂t = D ∂²C/∂x²∂C/∂t = D ∂²C/∂x²
- D = D₀ exp(−Qd/RT)D = D₀ exp(−Qd/RT)
- x = vtx = vt
第二定律描述非穩態擴散:某點濃度隨時間的變化率與濃度曲線的曲率成正比。遊戲地圖的濃度場正是用它即時計算。The second law describes non-steady diffusion: the rate of change at a point is proportional to the curvature of the profile. The game's field is computed live from it.
「非穩態擴散」的意思是?"Non-steady-state diffusion" means:
- 完全沒有擴散No diffusion at all
- 濃度梯度為零Zero gradient
- D 隨位置隨機變化D varies randomly with position
- 某點的通量與濃度都隨時間改變,有累積或耗盡Flux and concentration at a point change with time; there is accumulation or depletion
非穩態時 C = C(x, t),大多數實際擴散(例如滲碳)都屬於此類。Non-steady: C = C(x, t). Most practical cases, such as carburizing, are like this.
誤差函數解 (Cx−C₀)/(Cs−C₀) = 1 − erf(x/2√(Dt)) 適用的條件是?The error-function solution applies when:
- 半無限固體、初始濃度 C₀ 均勻、表面濃度 Cs 保持固定The solid is semi-infinite, C₀ is uniform initially and the surface concentration Cs is held constant
- 已達穩態Steady state has been reached
- 表面濃度隨時間線性下降Surface concentration falls linearly with time
- 試片非常薄The specimen is very thin
邊界條件:t = 0 時 C = C₀;t > 0 時 x = 0 處 C = Cs,x = ∞ 處 C = C₀。Boundary conditions: C = C₀ at t = 0; for t > 0, C = Cs at x = 0 and C = C₀ at x = ∞.
例題 5.2:C₀ = 0.25%、Cs = 1.2%、目標 Cx = 0.8%。第一步算出 erf(z) 約為?Ex. 5.2: C₀ = 0.25%, Cs = 1.2%, target Cx = 0.8%. The first step gives erf(z) ≈
- 0.5789
- 0.8000
- 0.4210
- 0.2500
(0.8−0.25)/(1.2−0.25) = 0.5789 = 1 − erf(z),所以 erf(z) = 0.4210,查表內插得 z ≈ 0.392。(0.8−0.25)/(1.2−0.25) = 0.5789 = 1 − erf(z), so erf(z) = 0.4210; interpolating the table gives z ≈ 0.392.
承上,x = 0.5 mm、D = 1.6×10⁻¹¹ m²/s、z = 0.392,所需時間 t = x²/(4Dz²) 約為?Continuing: x = 0.5 mm, D = 1.6×10⁻¹¹ m²/s, z = 0.392. The time t = x²/(4Dz²) is about:
- 25,400 s ≈ 7.1 小時25,400 s ≈ 7.1 h
- 2,540 s ≈ 0.7 小時2,540 s ≈ 0.7 h
- 254,000 s ≈ 71 小時254,000 s ≈ 71 h
- 9,800 s ≈ 2.7 小時9,800 s ≈ 2.7 h
t = (5×10⁻⁴)² / [4(1.6×10⁻¹¹)(0.392)²] ≈ 25,400 s ≈ 7.1 h。t = (5×10⁻⁴)² / [4(1.6×10⁻¹¹)(0.392)²] ≈ 25,400 s ≈ 7.1 h.
在相同位置得到相同濃度(相同擴散效果),需滿足?To reach the same concentration at the same depth (the same diffusion effect) you need:
- 相同的 DThe same D
- 相同的 tThe same t
- 相同的 D/tThe same D/t
- 相同的 DtThe same Dt
x/2√(Dt) 相同即可,所以 Dt = 常數:溫度低(D 小)就要拉長時間。The same x/2√(Dt) is enough, so Dt is constant: lower temperature (smaller D) needs more time.
例題 5.3:Cu 在 Al 中,600 °C 時 D = 5.3×10⁻¹³、500 °C 時 D = 4.8×10⁻¹⁴ m²/s。600 °C 加熱 10 小時的效果,若改在 500 °C 需時?Ex. 5.3: Cu in Al, D = 5.3×10⁻¹³ at 600 °C and 4.8×10⁻¹⁴ m²/s at 500 °C. The 500 °C time matching 10 h at 600 °C is:
- 0.9 小時0.9 h
- 110.4 小時110.4 h
- 10 小時10 h
- 33.2 小時33.2 h
t₅₀₀ = D₆₀₀t₆₀₀/D₅₀₀ = (5.3×10⁻¹³)(10)/(4.8×10⁻¹⁴) = 110.4 h。降溫 100 度,要等 11 倍久!t₅₀₀ = D₆₀₀t₆₀₀/D₅₀₀ = (5.3×10⁻¹³)(10)/(4.8×10⁻¹⁴) = 110.4 h. Cool by 100 degrees and you wait 11 times longer!
同一溫度下,想讓滲碳深度變成 2 倍,時間要變成幾倍?At the same temperature, to double the carburized depth the time must be multiplied by:
- √2
- 2
- 4
- 8
x ∝ √(Dt),深度 2 倍需要 t 變 4 倍——這就是時之主大招 r = k√t 的意思。x ∝ √(Dt): doubling depth takes 4× the time, the idea behind Chronos's r = k√t.
關於誤差函數,下列何者正確?Which is true of the error function?
- erf(0) = 1erf(0) = 1
- erf(0) = 0,z → ∞ 時 erf(z) → 1erf(0) = 0, and erf(z) → 1 as z → ∞
- erf(z) 隨 z 線性增加erf(z) grows linearly with z
- erf(z) 可以大於 1erf(z) can exceed 1
所以在表面 (x = 0) C = Cs,深處 C → C₀。So at the surface (x = 0) C = Cs, and deep inside C → C₀.
D = 1×10⁻¹¹ m²/s,擴散 1 小時,特徵擴散距離 √(Dt) 約為?With D = 1×10⁻¹¹ m²/s for 1 hour, the characteristic length √(Dt) is about:
- 19 mm19 mm
- 1.9 mm1.9 mm
- 0.019 mm0.019 mm
- 0.19 mm0.19 mm
√(10⁻¹¹ × 3600) = √(3.6×10⁻⁸) ≈ 1.9×10⁻⁴ m = 0.19 mm。√(10⁻¹¹ × 3600) = √(3.6×10⁻⁸) ≈ 1.9×10⁻⁴ m = 0.19 mm.
擴散係數與溫度的關係(阿瑞尼斯型)是?The temperature dependence of the diffusion coefficient is:
- D = D₀ exp(−Qd/RT)D = D₀ exp(−Qd/RT)
- D = D₀ + QdTD = D₀ + QdT
- D = D₀ exp(+Qd/RT)D = D₀ exp(+Qd/RT)
- D = RT/QdD = RT/Qd
D 隨溫度呈指數增加;Qd 為擴散活化能,D₀ 為與溫度無關的前置因子。D rises exponentially with temperature; Qd is the activation energy and D₀ a temperature-independent pre-exponential.
以 ln D 對 1/T 作圖,得到的直線斜率是?Plotting ln D against 1/T gives a straight line whose slope is:
- D₀D₀
- +Qd/R+Qd/R
- −Qd/R−Qd/R
- ln D₀ln D₀
ln D = ln D₀ − (Qd/R)(1/T):斜率 −Qd/R,截距 ln D₀。ln D = ln D₀ − (Qd/R)(1/T): slope −Qd/R, intercept ln D₀.
例題 5.4:Mg 在 Al 中,D₀ = 1.2×10⁻⁴ m²/s、Qd = 130 kJ/mol。550 °C 時的 D 約為?Ex. 5.4: Mg in Al, D₀ = 1.2×10⁻⁴ m²/s, Qd = 130 kJ/mol. D at 550 °C is about:
- 1.2 × 10⁻⁴ m²/s
- 6.7 × 10⁻¹³ m²/s
- 6.7 × 10⁻⁹ m²/s
- 5.6 × 10⁻¹⁰ m²/s
T = 823 K。D = 1.2×10⁻⁴ exp[−130000/(8.31×823)] = 1.2×10⁻⁴ × e⁻¹⁹ ≈ 6.7×10⁻¹³ m²/s。溫度一定要用 K!T = 823 K. D = 1.2×10⁻⁴ exp[−130000/(8.31×823)] = 1.2×10⁻⁴ × e⁻¹⁹ ≈ 6.7×10⁻¹³ m²/s. Always use kelvin!
若 Qd 以 eV/atom 表示,阿瑞尼斯式中應搭配哪個常數?If Qd is given in eV/atom, which constant goes with it?
- R = 8.314 J/(mol·K)R = 8.314 J/(mol·K)
- 亞佛加厥數Avogadro's number
- 法拉第常數Faraday's constant
- k = 8.62×10⁻⁵ eV/(atom·K)k = 8.62×10⁻⁵ eV/(atom·K)
J/mol 配 R = 8.314;eV/atom 配波茲曼常數 k = 8.62×10⁻⁵。單位要一致!J/mol goes with R = 8.314; eV/atom goes with Boltzmann's k = 8.62×10⁻⁵. Keep units consistent!
其他條件相同時,活化能 Qd 越大,擴散係數 D 會?All else equal, a larger activation energy Qd makes D:
- 越小Smaller
- 越大Larger
- 不變Unchanged
- 變成負值Negative
exp(−Qd/RT) 隨 Qd 增加而變小:能障越高,越難跳躍。exp(−Qd/RT) shrinks as Qd grows: a higher barrier means fewer successful jumps.
在鐵中,下列哪一個在相同溫度下擴散最快?In iron at the same temperature, which diffuses fastest?
- Fe 的自擴散Fe self-diffusion
- Ni(置換型)Ni (substitutional)
- C(間隙型)C (interstitial)
- 三者一樣快All the same
碳是小的間隙原子,Qd 較低、D 遠大於置換型原子與自擴散。Carbon is a small interstitial with a lower Qd, so its D is far larger than substitutional or self-diffusion.
為何空位擴散的活化能通常比間隙擴散高?Why is the activation energy for vacancy diffusion usually higher than for interstitial diffusion?
- 空位擴散不需要能量Vacancy diffusion needs no energy
- 除了移動原子,還需要形成空位的能量Energy is needed to form the vacancy as well as to move the atom
- 空位比間隙原子小Vacancies are smaller than interstitials
- 空位只在液體中存在Vacancies exist only in liquids
空位擴散的 Qd 包含空位形成能與原子移動能兩部分。The vacancy Qd includes both vacancy formation and atom migration energy.
「變軟的齒輪」案件中,爐溫低了 80 °C、時間又從 6 小時縮成 4 小時。最根本的原因是?In the "soft gear" case the furnace ran 80 °C too cold and time was cut from 6 h to 4 h. The root cause is:
- 鋼材牌號用錯The wrong steel grade
- 齒輪有裂縫The gears were cracked
- 碳擴散太快,穿透整個齒輪Carbon diffused too fast and went through the gear
- D 與 t 都變小,Dt 大幅下降,碳根本擴散不到應有深度Both D and t fell, so Dt dropped sharply and carbon never reached the required depth
x ∝ √(Dt):D 約降為 1/3、t 降為 2/3,Dt 約剩 1/4 甚至更少,滲碳深度遠不足。x ∝ √(Dt): D dropped to about a third and t to two-thirds, so Dt fell to a quarter or less and the case was far too thin.
半導體積體電路的「摻雜 (doping)」主要靠什麼製程?Doping of semiconductor integrated circuits relies mainly on:
- 鑄造Casting
- 冷軋Cold rolling
- 讓雜質原子在高溫下擴散進矽晶片Diffusing impurity atoms into the silicon wafer at high temperature
- 電鍍Electroplating
摻雜的兩步驟(預沉積與驅入)都是擴散控制的熱處理。Both doping steps (predeposition and drive-in) are diffusion-controlled heat treatments.
氣體分子會到處亂跑,但固體中「每個原子都有座位」。固體中原子要移動,關鍵是?Gas molecules wander freely, but in a solid every atom has a seat. For atoms to move in a solid, the key is:
- 晶格中有缺陷(空位)或間隙可跳,且溫度提供足夠能量Defects (vacancies) or interstitial sites to jump into, and enough thermal energy
- 固體必須先熔化The solid must melt first
- 必須施加外力推動An external force must push them
- 固體中原子完全不能移動Atoms in solids can never move
固體擴散靠空位或間隙,加上熱振動越過能障。「有人讓位,碳才能進去」。Solid-state diffusion uses vacancies or interstitial sites plus thermal energy to cross the barrier: someone has to make room.
隨機漫步中,每一步方向隨機,走了 n 步後的典型淨位移約與什麼成正比?In a random walk of n steps in random directions, the typical net displacement scales with:
- n
- n²
- 1/n
- √n
均方根位移 ∝ √n,對應巨觀的 x ∝ √(Dt)。The root-mean-square displacement ∝ √n, matching the macroscopic x ∝ √(Dt).
擴散的驅動力(本章的觀點)最主要是?In this chapter, the driving force for diffusion is mainly:
- 重力Gravity
- 濃度梯度The concentration gradient
- 晶粒大小Grain size
- 磁場A magnetic field
在菲克定律中,濃度梯度是驅動力;沒有梯度就沒有淨通量。In Fick's laws the concentration gradient is the driving force; no gradient means no net flux.
氫氣純化時讓氫氣通過鈀薄片,其他氣體被擋住。這利用的是?Hydrogen is purified by passing it through a thin palladium sheet that blocks other gases. This uses:
- 穩態擴散:氫原子穿過金屬薄片Steady-state diffusion of hydrogen atoms through the metal sheet
- 對流Convection
- 再結晶Recrystallization
- 凝固Solidification
薄片兩側濃度固定時達到穩態,氫以間隙方式穿透鈀。With fixed concentrations on both faces the flow is steady, and hydrogen diffuses interstitially through the Pd.
遊戲中「升溫領域」讓 T 由 300 K 提高,D 會如何變化?In the game, the Heat Zone raises T above 300 K. How does D change?
- 線性小幅增加It rises a little, linearly
- 減少It decreases
- 依 exp(−Qd/RT) 呈指數增加It rises exponentially as exp(−Qd/RT)
- 不變,溫度只影響 D₀Unchanged; T affects only D₀
指數關係讓小幅升溫也能大幅加快擴散——這就是熱處理要嚴格控制爐溫的原因。The exponential means a modest rise in T speeds diffusion a lot, which is why furnace temperature must be tightly controlled.
在同樣溫度下,碳在 BCC 的 α-Fe 與 FCC 的 γ-Fe 中,何者擴散較快?At the same temperature, is carbon diffusion faster in BCC α-Fe or FCC γ-Fe?
- γ-Fe(FCC)γ-Fe (FCC)
- α-Fe(BCC)α-Fe (BCC)
- 兩者相同The same
- 碳無法在鐵中擴散Carbon can't diffuse in iron
BCC 堆積較鬆(APF 0.68),碳在 α-Fe 的 Qd 較低(約 87 vs 148 kJ/mol),所以較快。BCC is less densely packed (APF 0.68) and carbon's Qd in α-Fe is lower (about 87 vs 148 kJ/mol), so it is faster.
遊戲中三條路的擴散係數「晶界捷徑 > 間隙之路 > 空位之路」,對應的道理是?In the game, D on the paths ranks grain boundary > interstitial > vacancy. The idea is:
- 結構較開放的路徑(晶界、表面)與小原子的間隙跳躍,阻力較小、擴散較快More open structures (grain boundaries, surfaces) and small interstitial jumps meet less resistance and diffuse faster
- 路越長擴散越快Longer paths diffuse faster
- 顏色越亮擴散越快Brighter paths diffuse faster
- 完全隨機設定It is completely arbitrary
晶界、表面原子排列較鬆散,稱為「短路擴散」;間隙擴散又比需要空位的體擴散快。Atoms at grain boundaries and surfaces are loosely packed ("short-circuit" paths); interstitial diffusion beats vacancy-assisted bulk diffusion.
穩態擴散中,若濃度剖面是直線,則各處的濃度梯度?In steady-state diffusion with a straight-line profile, the gradient along x is:
- 越往低濃度端越大Larger toward the low end
- 為零Zero
- 處處相同The same everywhere
- 隨時間增加Increasing with time
直線斜率固定,梯度處處相同,所以通量 J 處處相同。A straight line has a single slope, so the gradient, and therefore J, is the same everywhere.
滲碳時若把時間拉長為原來的 9 倍,滲碳深度會變成幾倍?If carburizing time is increased 9-fold, the case depth becomes:
- 9 倍9×
- 81 倍81×
- 4.5 倍4.5×
- 3 倍3×
x ∝ √t,√9 = 3。x ∝ √t, and √9 = 3.
濃度探針Concentration probe
歡迎來到新手教學!跟著上方提示完成 6 個小任務(約 3 分鐘)。Welcome! Follow the panel above to finish 6 short tasks (about 3 minutes).
① 移動:用 WASD、搖桿,或點地面,走到綠色光圈。Move: use WASD, the stick, or tap the ground to reach the green ring.
② 普攻:靠近訓練史萊姆,按住 {a} 或「攻擊」鈕(也可直接點它)。Attack: walk to the training slime and hold {a} or the ATK button (or tap the slime).
③ 技能:對史萊姆放出技能 1 {q} 或技能 2 {e}。每招都對應一個擴散觀念,提示會跳出來。Skill: cast skill 1 {q} or skill 2 {e} on the slime. Each skill shows the diffusion idea behind it.
④ 讀濃度場:地面的藍/紅色是兩方溶質的濃度 C(x,y),細線是等濃度線,亮白線是擴散前緣(C = 50%)。按 {v} 或「探針」鈕,看看 C(x) 剖面:曲線最陡處通量最大。Read the field: blue/red ground tint is solute concentration C(x,y), thin lines are iso-concentration contours and the bright line is the diffusion front (C = 50%). Press {v} or Probe to see the C(x) profile: the steepest part carries the largest flux.
⑤ 實驗室:按 {l} 或「實驗室」,回答一題觀念題或計算題(答對有金幣)。Lab: press {l} or Lab and answer one concept or calculation question (gold if correct).
⑥ 回城:按 {b} 或「回城」並站著不動 4 秒。在泉水旁可以買裝備、回血。Recall: press {b} or Recall and stand still for 4 s. At the fountain you heal and can shop.
探針冷卻中Probe cooling down
請輸入數值Please enter a number
正確答案:Answer:
+200 金!+200 gold!
擴散物種 in 母材Diffusing species in host
Fe in α-Fe (BCC)
Fe in γ-Fe (FCC)
C in α-Fe
C in γ-Fe
Cu in Cu
Zn in Cu
Al in Al
Cu in Al
Mg in Al
Cu in Ni
例題 5.1 穩態擴散通量Ex. 5.1 Steady-state flux
例題 5.2 滲碳需時多久Ex. 5.2 Carburizing time
例題 5.3 用時間換溫度Ex. 5.3 Trading temperature for time
例題 5.4 查表求 DEx. 5.4 Compute D from Table 5.2
一鐵片兩側分別置於滲碳與脫碳環境,已達穩態。在 x1 = {x1} mm 與 x2 = {x2} mm 處,碳濃度分別為 {c1} 與 {c2} kg/m3,擴散係數 D = {D} m2/s。求擴散通量 J。An iron plate has a carburizing atmosphere on one side and a decarburizing one on the other, at steady state. The carbon concentrations at x1 = {x1} mm and x2 = {x2} mm are {c1} and {c2} kg/m3; D = {D} m2/s. Find the diffusion flux J.
某合金含碳量 {C0}%,表面碳濃度提升並保持在 {Cs}%。在 {x} mm 深處,需時多久才達到 {Cx}%?合金視為半無限,D = {D} m2/s。(以小時作答)An alloy initially contains {C0}% C. The surface is raised to and held at {Cs}% C. How long until the concentration at {x} mm depth reaches {Cx}%? Treat it as semi-infinite with D = {D} m2/s. (Answer in hours.)
{sys} 的擴散係數在 {T1} °C 與 {T2} °C 時分別為 {D1} 與 {D2} m2/s。在 {T1} °C 需加熱多久,才能與 {T2} °C 加熱 {t2} 小時的擴散效果相同?(以小時作答)For {sys}, D = {D1} m2/s at {T1} °C and {D2} m2/s at {T2} °C. How long at {T1} °C gives the same diffusion result as {t2} h at {T2} °C? (Answer in hours.)
利用表 5.2,求 {sys} 在 {Tc} °C 時的擴散係數 D。(R = 8.314 J/mol·K)Using Table 5.2, find D for {sys} at {Tc} °C. (R = 8.314 J/mol·K){tbl}
穩態、線性剖面:Steady state, linear profile: J = −D (C2 − C1)/(x2 − x1) = −({D}) × ({c2} − {c1}) / (({x2} − {x1}) × 10−3 m) = {ans} kg/(m2·s). 記得先把 mm 換成 m!Convert mm to m first!
① (Cx − C0)/(Cs − C0) = ({Cx} − {C0})/({Cs} − {C0}) = {ratio} = 1 − erf(z)
② erf(z) = {erfz} ⇒ z ≈ {z} (查表 5.1 線性內插)(interpolate Table 5.1)
③ t = x2/(4Dz2) = ({x} × 10−3)2 / (4 × {D} × {z}2) = {ts} s = {ans} h
「擴散效果相同」= 同深度同濃度 ⇒ Dt 為常數(不需查 erf 表):"Same diffusion result" = same depth at same concentration ⇒ Dt = constant (no erf table needed):
t1 = D2t2/D1 = {D2} × {t2} / {D1} = {ans} h
D = D0 exp(−Qd/RT) = {D0} × exp(−{Q} / (8.314 × {TK})) = {ans} m2/s (溫度要換成 K;Qd 用 J/mol)(use kelvin, and Qd in J/mol)
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