[本揭示之實施形態之說明] 首先，條列說明本揭示之實施態樣。 另，於本說明書中「A～B」形式之記述意指範圍之上限下限(即A以上B以下)，於A中無單位之記載、僅於B中記載有單位之情形時，A之單位與B之單位相同。 [1]本揭示之一態樣之切削工具包含具備第1硬質相、結合相及Al2
O3
之燒結體。第1硬質相包含WC粒子。結合相包含含有選自Co及Ni之至少一種作為主成分之第1金屬相，再者包含含有選自Al及W之至少1種之第2金屬，及C。Al2
O3
為粒子狀，分散於燒結體中。上述燒結體於高溫下之耐磨耗性提高。藉由燒結體之高溫下之耐磨耗性之提高，可使切削工具長壽命化。 [2]結合相較佳為包含以下述式表示之化合物相： (Co，Ni)x
(Al，W)y
Cz
[式中，(Co，Ni)係選自Co及Ni之至少1種，(Al，W)係選自Al及W之至少1種，x、y及z係原子量比。]藉此，燒結體可於特別高溫下維持高硬度。 [3]較佳為x為0.6以上0.95以下，y為0.04以上0.32以下，z為0.003以上0.15以下。如此可望提高燒結體高溫下之耐磨耗性。 [4]較佳為x為0.75以上0.93以下，y為0.05以上0.2以下，z為0.005以上0.1以下。如此可望提高燒結體高溫下之耐磨耗性。 [5]較佳為x為0.8以上0.9以下，y為0.06以上0.12以下，z為0.01以上0.05以下。如此可望提高燒結體高溫下之耐磨耗性。 [6]燒結體較佳為進而包含第2硬質相。第2硬質相包含化合物或該化合物之固溶體(惟WC除外)，該化合物包含選自由Ti、Zr、Hf、Nb、Ta、Cr、Mo及W所組成之群中之1種以上之金屬，及選自由氮、碳、硼及氧所組成之群中之1種以上之元素。此處，第1硬質之體積比率大於第2硬質相。如此可望提高燒結體高溫下之耐磨耗性。 [7]較佳為Al2
O3
於燒結體中含有1體積%以上15體積%以下。該情形時，進而確實獲得高溫下之耐磨耗性之提高效果，且可望有抑制燒結體之強度降低之效果。 [8]較佳為Al2
O3
之圓相當直徑之平均值為0.1 μm以上2 μm以下，且其標準偏差為0.05 μm以上0.25 μm以下。該情形時，可望有燒結體之硬度提高之效果。又，可望有抑制燒結體之韌性降低之效果。 [9]較佳為Al2
O3
之圓相當直徑之平均值為0.2 μm以上1 μm以下，且其標準偏差為0.05 μm以上0.15 μm以下。該情形時，可望有燒結體之硬度進而提高之效果。又，可望有抑制燒結體之韌性降低之效果。 [10]較佳為Al2
O3
之圓相當直徑之平均值為0.3 μm以上0.5 μm以下，且其標準偏差為0.05 μm以上0.1 μm以下。該情形時，可望有燒結體之硬度進而提高之效果。又，可望有抑制燒結體之韌性降低之效果。 [11]較佳為Al2
O3
之粒子間距離之平均值為1 μm以上3 μm以下，且其標準偏差為0.5 μm以上1.5 μm以下。該情形時，可望有硬度韌性保持平衡之效果。 [12]燒結體中含有之O之質量相對於C之質量之比(O/C比)較佳為0.015以上0.061以下。該情形時，可望滿足[8]與[11]。 [13]燒結體中之氧含量較佳為0.1質量%以上0.4質量%以下。該情形時，可望有燒結體之硬度提高效果與缺損之抑制效果。 [14]結合相之晶格常數較佳為3.65 Å以上4.0 Å以下。該情形時，可望有於更高溫下維持燒結體之高硬度之效果，與抑制燒結體之缺損之效果。 [15]WC粒子之平均粒徑較佳為0.1 μm以上3 μm以下。該情形時，可望有抑制燒結體之缺損之效果。 [16]燒結體中之結合相之含有率較佳為2質量%以上且未達10質量%。該情形時，可望有抑制燒結體之缺損之效果，及抑制燒結體之高溫硬度降低之效果。 [本揭示之實施形態之詳情] 以下說明本揭示之實施形態(以下記作「本實施形態」)。惟以下之說明並非限定於本揭示。又，本說明書中以化學式表示化合物等之情形時，未特別限定原子比時，包含先前眾所周知之原子比，而未必限定於化學計量範圍者。 ＜切削工具＞ 本實施形態之切削工具包含下述燒結體。再者，作為切削工具，可例示鑽孔器、立銑刀、鑽孔器用刀頭更換型切削刀片、立銑刀用刀頭更換型切削刀片、銑刀加工用刀頭更換型切削刀片、旋削加工用刀頭更換型切削刀片、金工鋸、齒輪刀具、鉸刀、絲錐等。 ＜燒結體＞ 本實施形態之燒結體包含第1硬質相、結合相及Al2
O3
。燒結體只要包含該等，則亦可包含該等以外之成分。第1硬質相包含WC粒子。例如，第1硬質相係由複數個粒子之集合體構成，結合相作為粒子散佈於第1硬質相中。Al2
O3
為粒子狀，分散於燒結體中。 結合相包含含有選自Co及Ni之至少一種作為主成分之第1金屬，再者包含含有選自Al及W之至少1種之第2金屬，及C。再者，所謂「主成分」意指構成結合相之成分中，混合比率(質量%)最大之成分。如此，上述燒結體於結合相中含有C。因此，結合相之高溫硬度藉由固溶強化而提高，從而燒結體在高溫下之耐磨耗性提高。 又，包含硬質相與結合相之超硬合金中，結合相由耐熱合金(Co基超合金、Ni基超合金等)構成而非金屬Co。耐熱合金為使用於噴射引擎、燃氣渦輪機等在高溫下使用之零件之材料，在高溫下之耐熱性優良。再者，上述燒結體包含硬度高於WC之Al2
O3
。藉此，燒結體本身之硬度提高。 第1硬質相與結合相較佳為以分散於燒結體中之狀態含有。藉此，燒結體在高溫下之耐磨耗性提高。又，第1硬質相與結合相兩者，較佳為與包含第1金屬(Co，Ni)之母相即γ相一起，以分散於燒結體中之狀態含有。藉此，可獲得兼具高溫硬度與耐缺損性之燒結體。更佳為兩者以於燒結體中均一地分散之狀態含有。此處，所謂分散狀態是指第1硬質相與結合相接，在同種相彼此之接觸較少之狀態下存在於燒結體中。 結合相較佳為包含下述式表示之化合物相： (Co，Ni)x
(Al，W)y
Cz
[式中，(Co，Ni)係選自Co及Ni之至少1種，(Al，W)係選自Al及W之至少1種，x、y及z係原子量比。] 另，亦可於結合相中包含(固溶)氧。 此種燒結體於結合相中[包含第1金屬(Co，Ni)及第2金屬(Al，W)之母相(γ相)中]包含以(Co，Ni)x
(Al，W)y
Cz
表示之化合物相，從而可於特別高溫下維持高硬度。 較佳為x為0.6以上0.95以下，y為0.04以上0.32以下，z為0.003以上0.15以下。如此可望提高燒結體在高溫下之耐磨耗性。 較佳為x為0.75以上0.93以下，y為0.05以上0.2以下，z為0.005以上0.1以下。如此可望提高燒結體在高溫下之耐磨耗性。 較佳為x為0.8以上0.9以下，y為0.06以上0.12以下，z為0.01以上0.05以下。如此可望提高燒結體在高溫下之耐磨耗性。 燒結體較佳為進而包含第2硬質相。第2硬質相包含化合物或該化合物之固溶體(惟WC除外)，該化合物包含：選自由Ti、Zr、Hf、Nb、Ta、Cr、Mo及W所組成之群中之1種以上金屬，及選自由氮、碳、硼及氧所組成之群中之1種以上元素。此處，第1硬質之體積比率大於第2硬質相。 由於結合相與第1硬質相之親和性高於第2硬質相，故第1硬質相之體積比率大於第2硬質相，從而可望提高燒結體之耐磨耗性等，提高燒結體在高溫下之耐磨耗性。 較佳為Al2
O3
於燒結體中含有1體積%以上15體積%以下。若Al2
O3
之量過少，則可能無法獲得高溫下之耐磨耗性之提高效果。另一方面，若Al2
O3
之量過多，則燒結體之強度降低，易產生缺損。因此，Al2
O3
之含有率在上述範圍內之情形時，將可更確實獲得高溫下之耐磨耗性之提高效果，可望有抑制燒結體之強度降低之效果。 較佳為Al2
O3
之圓相當直徑之平均值為0.1 μm以上2 μm以下，且其標準偏差為0.05 μm以上0.25 μm以下。由於Al2
O3
較微細，故可望有燒結體之硬度進而提高之效果。另一方面，若Al2
O3
過於微細，則燒結體之韌性降低，易產生缺損，故可望有於上述範圍內抑制燒結體之韌性降低之效果。 較佳為Al2
O3
之圓相當直徑之平均值為0.2 μm以上1 μm以下，且其標準偏差為0.05 μm以上0.15 μm以下。由於Al2
O3
較微細，故可望有燒結體之硬度進而提高之效果。另一方面，若Al2
O3
過於微細，則燒結體之韌性降低，易產生缺損，故可望有於上述範圍內抑制燒結體之韌性降低之效果。 較佳為Al2
O3
之圓相當直徑之平均值為0.3 μm以上0.5 μm以下，且其標準偏差為0.05 μm以上0.1 μm以下。由於Al2
O3
較微細，故可望有燒結體之硬度進而提高之效果。另一方面，若Al2
O3
過於微細，則燒結體之韌性降低，易產生缺損，故可望有於上述範圍內抑制燒結體之韌性降低之效果。 較佳為Al2
O3
之粒子間距離之平均值為1 μm以上3 μm以下，且其標準偏差為0.5 μm以上1.5 μm以下。藉由結合相均一地分散，可望有硬度韌性保持平衡之效果。若粒子間距離超出1～3 μm，則結合相之分散程度產生偏差，易產生缺損。再者，所謂粒子間距離是指對於Al2
O3
粒子之各者逐一設定者。任意一個Al2
O3
粒子之「粒子間距離」係該Al2
O3
粒子之重心點與在離該重心點最近之位置具有重心點之另一Al2
O3
粒子之距離。而所謂「粒子間距離之平均值」是指所有「粒子間距離」之平均值。 燒結體中含有之O之質量相對於C之質量之比(O/C比)較佳為0.015以上0.061以下。於該範圍內，Al2
O3
均一地分散析出，可望滿足[8]與[11]。 燒結體中之氧含量較佳為0.1質量%以上0.4質量%以下。若氧含量為0.1質量%以下，則Al2
O3
有可能未析出而未提高硬度。若氧含量為0.4質量%以上，則Al2
O3
有可能凝聚而易產生缺損。因此，氧含量在上述範圍內之情形時，可望有燒結體之硬度提高效果與缺損之抑制效果。 結合相之晶格常數較佳為3.65 Å以上4.0 Å以下。結合相之晶格常數為3.65 Å以上之情形時，C固溶而產生變形，從而可於更高溫下維持高硬度。結合相之晶格常數大於4.0 Å之情形時，變形變大，可能於結合相內產生龜裂而產生缺損。因此，結合相之晶格常數在上述範圍內之情形時，可望有於更高溫下維持燒結體之高硬度之效果，與抑制燒結體之缺損之效果。 WC粒子之平均粒徑較佳為0.1 μm以上3 μm以下。平均粒徑為0.1 μm以下之情形時，燒結體之韌性降低，可能產生缺損。另一方面，平均粒徑為5 μm以上之情形時，燒結體之強度降低，可能易產生缺損。因此，WC粒子之平均粒徑在上述範圍內之情形時，可望有抑制燒結體之缺損之效果。 燒結體中之結合相之含有率較佳為2質量%以上且未達10質量%。結合相之含有率少於2質量%之情形時，燒結體之韌性可能降低，而易產生缺損。結合相之含有率多於10質量%之情形時，燒結體之高溫硬度可能容易降低。因此，結合相之含有率在上述範圍內之情形時，可望有抑制燒結體之缺損之效果，與抑制燒結體之高溫硬度降低之效果。 另，可如下確認燒結體包含硬質相(第1硬質相及第2硬質相)、結合相(合金粉末)及Al2
O3
，以及硬質相(第1硬質相及第2硬質相)、結合相或Al2
O3
之體積含有率、WC粒子(第1硬質相)之平均粒徑、Al2
O3
之圓相當直徑或粒子間距離、及結合相之組成等。 首先，製作包含燒結體之任意剖面之試料。剖面之製作可使用聚焦離子束裝置、氬離子剖面拋光儀裝置等。接著，將經加工之剖面以SEM(Scanning Electron Microscope:電子顯微鏡)以10000倍拍攝，獲得10視野量之電子圖像。接著，使用附屬之EPMA(Electron Probe Micro-Analysis：電子探針微分析)或EDX(Energy Dispersive X-ray spectrometry：能量色散X射線光譜儀)，對各電子圖像中之特定區域(12 μm×9 μm)進行元素分佈分析。 基於獲得之元素分佈分析，將包含WC之區域作為第1硬質相，將不包含WC之區域且包含第1金屬(Ni，Co)及第2金屬(Al，W)及C之區域作為結合相，將包含Al及O之區域作為Al2
O3
。藉此，確認燒結體包含硬質相(第1硬質相及第2硬質相)、結合相及Al2
O3
。又，由元素分佈分析而決定結合相之組成及燒結體中之結合相之比例(體積%)。再者，根據燒結條件不同，除了硬質相及結合相以外，有存在空穴之情形。 再者，利用圖像解析軟體(「Mac-View I」、Mountech股份公司製)，算出散佈於燒結體中之Al2
O3
之圓相當直徑(具有與粒子之面積相同面積之虛擬圓之直徑)之平均值與其標準偏差，及WC粒子之平均粒徑。再者，各值係以10視野分析所得的結果之平均值。 又，構成硬質相(第1硬質相及第2硬質相)之化合物粒子之組成及WC粒子(第1硬質相)及化合物粒子之各比例(質量%)可由下確認：將燒結體粉碎，根據ICP發光分光分析法，求得粉碎物中各元素之含有比例，基於此試算各成分之組成比。 另，燒結體中之WC粒子之含有比例比較高，因此存在許多WC粒子彼此相鄰之區域。相鄰之WC粒子彼此可藉由自元素分佈分析結果與SEM圖像所得之反射電子像加以區別。反射電子像係用於觀察因各WC粒子之晶體取向之差異之顏色差異(濃淡)之故。 ＜燒結體之製造＞ 於本揭示之一實施形態中，首先使用第1金屬(Co，Ni)及第2金屬(Al，W)作為原料，藉由霧化、電弧溶解、電漿處理等而製作結合相。 另，製作結合相粉末時，除了第1金屬(Co，Ni)及第2金屬(Al，W)以外，亦可添加V、Ti、Nb、Ta、B、C等。 將所得之結合相例如藉由珠磨機、球磨機、噴磨機等予以粉碎，成為結合相粉末。結合相粉末之平均粒徑較佳為0.3～3 μm。作為珠磨機/球磨機所使用之珠/球，列舉例如粒徑為0.1～3 mm之鋁製、氮化矽製、超硬合金製珠/球，作為分散媒，列舉例如乙醇或丙酮、液體氮等。珠磨機/球磨機之處理時間例如為30分～200小時。使由珠磨機/球磨機所得之漿例如於大氣中乾燥。經過時間而粉碎，且使之於大氣中乾燥，藉此吸附空氣中之氧而燒結時，吸附氧與結合相中之Al反應，可使Al2
O3
析出。又，作為其他方法，以噴磨機粉碎之情形時，使用空氣作為粉碎氣體源，即使增長粉碎時間亦可獲得吸附氧之結合相粉末。如後述，即使直接添加Al2
O3
粉末亦可獲得使Al2
O3
分散之燒結體，但如本方法般使Al2
O3
析出，更可使Al2
O3
之粒徑微細而較佳。 接著，藉由磨碎機、球磨機、砂漿等，將所得之結合相粉末與另外準備之WC粒子粉末混合。此時，考慮結合相中含有之C量，添加適當之C。 混合係於對大氣開放之狀態下進行。藉此，將氧納入混合物中。為使氧化鋁(Al2
O3
)均一地分散於燒結體(硬質材料)中，以將氧充分且均一地納入混合物中之方式，混合時間較佳為6～20小時。 作為球磨機所使用之球，列舉例如氧化鋁製、氮化矽製或超硬合金製之直徑3 mm之球，作為分散媒，列舉例如乙醇或丙酮、液體氮等。處理時間例如為3～20小時。藉由使由混合所得之漿例如於大氣中乾燥而獲得混合粉末。混合時，作為分散於燒結體中之Al2
O3
，亦可添加Al2
O3
微粉末(0.01～0.5 μm)。 將所得之混合粉末放入例如超硬合金製之模具(Ta膠囊等)，藉由壓製而獲得加壓成形體。壓製之壓力較佳為10 MPa～16 GPa，例如為100 MPa。接著，將加壓成形體於真空中燒結。燒結之溫度較佳為1000～1800℃。燒結時間例如為1小時左右。此處，例如以如下之方式進行控制：於燒結時，將400℃之保持時間設為30分～5小時，從而使成形體中含有之C脫離，使最終燒結體中含有之O之質量相對於C之質量之比(C/O之比)成為期望值。藉此，使第1硬質相(WC粒子)與結合相緻密燒結，且微細Al2
O3
於燒結體中析出，從而可形成高溫下之耐磨耗性提高之燒結體。 再者，將燒結後之冷卻速度設為例如2～20℃/分。藉此，析出以下式表示之化合物相。 (Co，Ni)x
(Al，W)y
Cz
[式中，(Co，Ni)為第1金屬，(Al，W)為第2金屬，x、y及z為原子量比。] 其後，例如以1400℃、1000 atm之條件進行1小時之熱均壓(HIP：Hot Isostatic Pressing)處理，而可獲得燒結體(合金)。 再者，WC粒子之平均粒徑較佳為0.1～10 μm，燒結體(硬質材料)中之WC粒子之含有率較佳為50～99體積%。如為此種粒徑範圍與組成範圍，則可望所得燒結體之硬度進而變高。再者，WC粒子之平均粒徑可根據使用上述之元素分佈分析及圖像解析軟體之方法而測定。 又，本實施形態之燒結體亦可於無損本揭示之效果之範圍內包含不可避免之雜質(B、N、O等)。又，本實施形態之燒結體亦可於其組織中包含游離碳或稱為η相之異常層。 [實施例] 以下，舉出實施例更詳細地說明本揭示，但本揭示並非限定於此。 ＜實施例1～50＞ 以42.5Co-40Ni-10W-7.5Al(原子%)之組成混合金屬粉，藉由霧化法製作結合相。(實施例1～50所使用之金屬粉全部相同。) 使用粒徑1 μm之超硬球將所得之結合相藉由球磨機加以粉碎。使所得之漿於大氣中乾燥，獲得結合相粉末。 將所得之結合相粉末、表1及表2記載之組成之硬質粒子(第1硬質相及第2硬質相)及碳粉末，與直徑3.5 mm之超硬合金製之球與乙醇一起投入於大氣開放型磨碎機中混合。磨碎機之混合時間如表1及表2所記載。使所得之漿於大氣中乾燥，獲得混合粉末。 將混合粉末填充於超硬合金製模具中，以100 MPa之壓力壓製，而獲得加壓成形體。 將該加壓成形體以表1及表2所記載之燒結條件，以1450℃燒結1小時。此時，藉由如表1及表2般設定氫氛圍中400℃之保持時間，而使成形體中含有之C脫離，以最終燒結體含有之C/O比成表3及表4之方式進行控制。再者，如表1及表2記載般調整冷卻速度。藉此，析出以(Co，Ni)x
(Al，W)y
Cz
表示之化合物相。 其後，例如以1400℃、1000 atm之條件進行1小時之熱均壓(HIP：Hot Isostatic Pressing)處理，而獲得燒結體(硬質材料)。 ＜比較例1＞ 以磨碎機進行混合時，藉由使用密閉式磨碎機，而抑制混合物之氧化。又，使該混合後所得之漿於氮氛圍中乾燥。又，燒結條件設為真空、1450℃、1小時。又，結合相之配合比及製作條件如表2所示。此外之點設為與實施例1相同，獲得燒結體。 ＜比較例2～3＞ 燒結條件設為真空，以1450℃燒結1小時。又，結合相之配合比及製作條件如表2所示。此外之點設為與實施例1相同，獲得燒結體。 ＜比較例4＞ 取代42.5Co-40Ni-10W-7.5Al(原子%)之金屬粉，使用1.2 μm之金屬Co。又，結合相之配合比及製作條件如表2所示。此外之點設為與比較例1相同，獲得燒結體。 ＜切削工具之製作＞ 將上述各實施例及各比較例所得之燒結體(硬質材料)藉由線放電加工而切斷並精加工，製作前端鼻R為0.8 mm之切削工具。 [表1][表2]＜切削工具之評估＞ 對上述製作之各實施例及各比較例之切削工具各者，於下述之切削條件下，將Inconel(註冊商標)718(產品名、Inconel公司製)作為被削材，以NC車床進行切削試驗，測定切削0.2 km後之切削工具之退刀面之磨耗量(μm)與邊界磨耗量(μm)(參照圖1)。 切削速度：50 m/分 切口量：0.2 mm 輸送量：0.1 mm/rev 切削油：有 ＜燒結體之物性評估＞ 與上述實施形態說明之方法同樣地測定燒結體包含硬質相(第1硬質相及第2硬質相)、結合相(合金粉末)及Al2
O3
、以及硬質相(第1硬質相及第2硬質相)、結合相或Al2
O3
之體積含有率、及結合相之組成等。 燒結體中之氧量及C量係將燒結體粉碎，藉由ICP發光分光分析法予以測定。 結合相之晶格常數係藉由TEM觀察之選區之EDS分析及電子繞射像而特定。再者，作為TEM，使用JEM-2100F/Cs(日本電子(股)製)。作為Cs收集器，使用CESCOR(CEOS公司製)。作為EDS機，使用JED2300系列 dry SD60GV檢測器(日本電子(股)製)。TEM觀察條件設為：加速電壓：200 kV，探針尺寸：0.13 nm。 [表3]※1邊界磨耗係因強度降低或缺損、離子脫落而磨耗變大之部分。 [表4]※2因刀頭缺損而無法測定。 ※3因刀頭缺損而無法測定。 ※4因刀頭缺損而無法測定。 ※5於切削0.1 km之時點刀頭缺損，故中止試驗。 由表3及表4所示之結果可知，本揭示之切削工具即實施例1～實施例50中，高溫下之耐磨耗性提高。 由實施例1～實施例10之結果可知，結合相包含式： (Co，Ni)x
(Al，W)y
Cz
[式中，(Co，Ni)為第1金屬，(Al，W)為第2金屬，x、y及z為原子量比。] 以上式表示之化合物相之情形時，x為60原子%以上95原子%以下，y為4原子%以上32原子%以下，z為0.3原子%以上15原子%以下時，高溫下之耐磨耗性進而提高。又可知，x為75原子%以上93原子%以下，y為5原子%以上20原子%以下，z為0.5原子%以上10原子%以下時，高溫下之耐磨耗性進而提高。又可知，x為80原子%以上90原子%以下時，y為6原子%以上12原子%以下，z為1原子%以上5原子%以下時，高溫下之耐磨耗性最提高。 由實施例11及12之結果可知，燒結體即使包含第2硬質相之情形，在第1硬質之體積比率大於第2硬質相之情形時，高溫下之耐磨耗性仍提高。由實施例50之結果可知，包含第2硬質相較於未包含第2硬質相之情形，在更高溫下之耐磨耗性提高。 由實施例13及14之結果認為，若燒結體中之Al2
O3
之含有率過少，則可能無法獲得高溫下之耐磨耗性提高之效果。另一方面，由實施例48及49之結果認為，若燒結體中之Al2
O3
之含有率過多，則燒結體之強度降低，易產生缺損。 由實施例15～實施例17之結果認為，由於Al2
O3
較微細，可望有燒結體之硬度進而提高之效果，但另一方面，若Al2
O3
過於微細，則燒結體之韌性降低，易產生缺損。另一方面，由實施例43～47之結果認為，若Al2
O3
之直徑過大，則燒結體之強度降低，易產生缺損。 由實施例18及19之結果認為，若燒結體中含有之Al2
O3
之粒子間距離過小，則結合相之分散程度有所偏頗，而易產生缺損。另一方面，由實施例41及42之結果認為，若燒結體中含有之Al2
O3
之粒子間距離過大，則燒結體之強度降低，易產生缺損。 由實施例20及21之結果、以及實施例22及23之結果認為，燒結體中含有之O之質量相對於C之質量之比(O/C比)過小，且燒結體中之氧含量(氧合金量)過少之情形時，因Al2
O3
過少，故高溫下之耐磨耗性降低。另一方面，由實施例37及38之結果、以及實施例39及40之結果認為，燒結體中之氧含量(氧合金量)過多之情形時，及燒結體中含有之O之質量相對於C之質量之比(O/C比)過大之情形時，Al2
O3
凝聚，易產生缺損。 由實施例24及25之結果認為，若結合相之晶格常數較小，則高溫下之耐磨耗性降低。另一方面，由實施例35及36之結果認為，若結合相之晶格常數過大，則因C之固溶所致之變形變大，於結合相內產生龜裂而易產生缺損。 由實施例26及27之結果認為，若WC粒子之平均粒徑較小，則燒結體之韌性降低，易產生缺損。另一方面，由實施例33及34之結果認為，若WC粒子之平均粒徑過大，則燒結體之強度降低，易產生缺損。 由實施例28～32之結果認為，若結合相之含有率過少，則燒結體之韌性降低，易產生缺損，另一方面，若結合相之含有率過多，則燒結體之高溫硬度易降低。 吾人應理解，本揭示之實施形態及實施例之所有之點皆為例示而非限制性者。本揭示之範圍係由申請專利範圍所示而非上述實施形態，且涵蓋與申請專利範圍均等之意涵及範圍內之所有變更。[Explanation of the embodiment of the present disclosure] First, the implementation aspects of the present disclosure will be described in a row. In addition, the description in the form of "A to B" in this specification means the lower limit of the upper limit of the range (that is, A is higher than B, and B is lower). When there is no unit description in A and only the unit is recorded in B, the unit of A is Same unit as B. [1] A cutting tool according to one aspect of the present disclosure includes a sintered body including a first hard phase, a bonded phase, and Al 2 O 3 . The first hard phase contains WC particles. The bonded phase includes a first metal phase containing at least one selected from Co and Ni as a main component, and further includes a second metal containing at least one selected from Al and W, and C. Al 2 O 3 is particulate and dispersed in a sintered body. The abrasion resistance of the sintered body at high temperatures is improved. By increasing the wear resistance of the sintered body at high temperatures, the life of the cutting tool can be extended. [2] The binding phase preferably includes a compound phase represented by the following formula: (Co, Ni) x (Al, W) y C z [wherein (Co, Ni) is at least one selected from Co and Ni. (Al, W) is at least one selected from Al and W, and x, y, and z are atomic weight ratios. ] As a result, the sintered body can maintain high hardness at a particularly high temperature. [3] Preferably, x is 0.6 or more and 0.95 or less, y is 0.04 or more and 0.32 or less, and z is 0.003 or more and 0.15 or less. This is expected to improve the wear resistance of the sintered body at high temperatures. [4] Preferably, x is 0.75 or more and 0.93 or less, y is 0.05 or more and 0.2 or less, and z is 0.005 or more and 0.1 or less. This is expected to improve the wear resistance of the sintered body at high temperatures. [5] Preferably, x is 0.8 or more and 0.9 or less, y is 0.06 or more and 0.12 or less, and z is 0.01 or more and 0.05 or less. This is expected to improve the wear resistance of the sintered body at high temperatures. [6] The sintered body preferably further contains a second hard phase. The second hard phase contains a compound or a solid solution of the compound (except WC), which contains one or more metals selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Cr, Mo, and W And one or more elements selected from the group consisting of nitrogen, carbon, boron, and oxygen. Here, the volume ratio of the first hard phase is larger than that of the second hard phase. This is expected to improve the wear resistance of the sintered body at high temperatures. [7] Preferably, Al 2 O 3 is contained in the sintered body in an amount of 1% by volume or more and 15% by volume or less. In this case, the effect of improving the abrasion resistance at high temperatures is surely obtained, and the effect of suppressing the reduction in the strength of the sintered body is expected. [8] It is preferable that the average value of the circle equivalent diameter of Al 2 O 3 is 0.1 μm or more and 2 μm or less, and the standard deviation thereof is 0.05 μm or more and 0.25 μm or less. In this case, the effect of improving the hardness of the sintered body is expected. Moreover, the effect which suppresses the fall of the toughness of a sintered compact is expected. [9] Preferably, the average value of the circle equivalent diameter of Al 2 O 3 is 0.2 μm or more and 1 μm or less, and the standard deviation thereof is 0.05 μm or more and 0.15 μm or less. In this case, the effect of further improving the hardness of the sintered body is expected. Moreover, the effect which suppresses the fall of the toughness of a sintered compact is expected. [10] The average value of the circle equivalent diameter of Al 2 O 3 is preferably 0.3 μm or more and 0.5 μm or less, and the standard deviation is 0.05 μm or more and 0.1 μm or less. In this case, the effect of further improving the hardness of the sintered body is expected. Moreover, the effect which suppresses the fall of the toughness of a sintered compact is expected. [11] It is preferable that the average value of the inter-particle distance of Al 2 O 3 is 1 μm or more and 3 μm or less, and the standard deviation thereof is 0.5 μm or more and 1.5 μm or less. In this case, the effect of maintaining the balance of hardness and toughness is expected. [12] The ratio of the mass of O contained in the sintered body to the mass of C (O / C ratio) is preferably 0.015 or more and 0.061 or less. In this case, [8] and [11] are expected to be satisfied. [13] The oxygen content in the sintered body is preferably from 0.1% by mass to 0.4% by mass. In this case, the effect of improving the hardness of the sintered body and the effect of suppressing the defects are expected. [14] The lattice constant of the bonded phase is preferably 3.65 Å to 4.0 Å. In this case, the effect of maintaining the high hardness of the sintered body at a higher temperature and the effect of suppressing the defect of the sintered body are expected. [15] The average particle diameter of the WC particles is preferably 0.1 μm or more and 3 μm or less. In this case, the effect of suppressing the defect of the sintered body is expected. [16] The content of the binding phase in the sintered body is preferably 2% by mass or more and less than 10% by mass. In this case, the effect of suppressing the defect of the sintered body and the effect of suppressing the reduction in the high-temperature hardness of the sintered body are expected. [Details of Embodiment of the Present Disclosure] The following describes the embodiment of the present disclosure (hereinafter referred to as "this embodiment"). However, the following description is not limited to this disclosure. When a compound or the like is expressed by a chemical formula in the present specification, when the atomic ratio is not particularly limited, it includes a conventionally known atomic ratio and is not necessarily limited to a stoichiometric range. <Cutting Tool> The cutting tool of this embodiment includes the following sintered body. Examples of the cutting tool include a drill, an end mill, a cutting insert for a drill, a cutting insert for an end milling cutter, a cutting insert for a milling cutter, a cutting insert for a milling cutter, and a turning operation. Replacement cutting inserts for machining, metalworking saws, gear cutters, reamers, taps, etc. <Sintered body> The sintered body of this embodiment includes a first hard phase, a bonded phase, and Al 2 O 3 . The sintered body may contain components other than these as long as it contains these. The first hard phase contains WC particles. For example, the first hard phase is composed of an aggregate of a plurality of particles, and the bonded phase is dispersed as particles in the first hard phase. Al 2 O 3 is particulate and dispersed in a sintered body. The binding phase contains a first metal containing at least one selected from Co and Ni as a main component, and further contains a second metal containing at least one selected from Al and W, and C. The "main component" means a component having the largest mixing ratio (mass%) among the components constituting the bonded phase. As such, the sintered body contains C in the bonded phase. Therefore, the high-temperature hardness of the bonded phase is increased by solid solution strengthening, so that the abrasion resistance of the sintered body at high temperature is improved. Further, in a cemented carbide including a hard phase and a bonding phase, the bonding phase is composed of a heat-resistant alloy (Co-based superalloy, Ni-based superalloy, etc.) instead of metal Co. Heat-resistant alloys are materials used in parts used at high temperatures, such as injection engines and gas turbines, and have excellent heat resistance at high temperatures. The sintered body contains Al 2 O 3 having a hardness higher than that of WC. Thereby, the hardness of the sintered body itself is improved. The first hard phase and the bonded phase are preferably contained in a state of being dispersed in the sintered body. This improves the wear resistance of the sintered body at high temperatures. Both the first hard phase and the bonding phase are preferably contained in a state of being dispersed in the sintered body together with the γ phase, which is the mother phase containing the first metal (Co, Ni). Thereby, a sintered body having both high-temperature hardness and defect resistance can be obtained. More preferably, both of them are contained in a state of being uniformly dispersed in the sintered body. Here, the dispersed state means that the first hard phase is in contact with the bonding phase, and exists in the sintered body in a state where the same phase has less contact with each other. The binding phase preferably includes a compound phase represented by the following formula: (Co, Ni) x (Al, W) y C z [wherein (Co, Ni) is at least one selected from Co and Ni, (Al , W) is at least one selected from Al and W, and x, y, and z are atomic weight ratios. It is also possible to include (solid solution) oxygen in the binding phase. Such a sintered body includes (Co, Ni) x (Al, W) y in the bonded phase [including the mother phase (γ phase) of the first metal (Co, Ni) and the second metal (Al, W)]. The compound phase represented by C z can maintain high hardness at particularly high temperatures. Preferably, x is 0.6 or more and 0.95 or less, y is 0.04 or more and 0.32 or less, and z is 0.003 or more and 0.15 or less. This is expected to improve the wear resistance of the sintered body at high temperatures. Preferably, x is 0.75 or more and 0.93 or less, y is 0.05 or more and 0.2 or less, and z is 0.005 or more and 0.1 or less. This is expected to improve the wear resistance of the sintered body at high temperatures. Preferably, x is 0.8 or more and 0.9 or less, y is 0.06 or more and 0.12 or less, and z is 0.01 or more and 0.05 or less. This is expected to improve the wear resistance of the sintered body at high temperatures. The sintered body preferably further contains a second hard phase. The second hard phase contains a compound or a solid solution of the compound (except for WC), the compound containing: one or more metals selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Cr, Mo, and W And one or more elements selected from the group consisting of nitrogen, carbon, boron, and oxygen. Here, the volume ratio of the first hard phase is larger than that of the second hard phase. Because the affinity of the binding phase and the first hard phase is higher than that of the second hard phase, the volume ratio of the first hard phase is larger than that of the second hard phase, which can increase the wear resistance of the sintered body and improve the sintered body at high temperature Lower abrasion resistance. Al 2 O 3 is preferably contained in a sintered body in an amount of 1% by volume or more and 15% by volume or less. If the amount of Al 2 O 3 is too small, the effect of improving abrasion resistance at high temperatures may not be obtained. On the other hand, when the amount of Al 2 O 3 is too large, the strength of the sintered body is reduced, and defects are liable to occur. Therefore, when the content rate of Al 2 O 3 is within the above range, the effect of improving the abrasion resistance at high temperature can be more surely obtained, and the effect of suppressing the reduction in strength of the sintered body can be expected. The average value of the circle equivalent diameter of Al 2 O 3 is preferably 0.1 μm or more and 2 μm or less, and the standard deviation is preferably 0.05 μm or more and 0.25 μm or less. Since Al 2 O 3 is relatively fine, an effect of further increasing the hardness of the sintered body is expected. On the other hand, if Al 2 O 3 is too fine, the toughness of the sintered body is reduced, and defects are liable to occur. Therefore, the effect of suppressing the decrease in toughness of the sintered body within the above range is expected. The average value of the circle equivalent diameter of Al 2 O 3 is preferably 0.2 μm or more and 1 μm or less, and the standard deviation is preferably 0.05 μm or more and 0.15 μm or less. Since Al 2 O 3 is relatively fine, an effect of further increasing the hardness of the sintered body is expected. On the other hand, if Al 2 O 3 is too fine, the toughness of the sintered body is reduced, and defects are liable to occur. Therefore, the effect of suppressing the decrease in toughness of the sintered body within the above range is expected. The average value of the circle equivalent diameter of Al 2 O 3 is preferably 0.3 μm or more and 0.5 μm or less, and the standard deviation is preferably 0.05 μm or more and 0.1 μm or less. Since Al 2 O 3 is relatively fine, an effect of further increasing the hardness of the sintered body is expected. On the other hand, if Al 2 O 3 is too fine, the toughness of the sintered body is reduced, and defects are liable to occur. Therefore, the effect of suppressing the decrease in toughness of the sintered body within the above range is expected. The average value of the inter-particle distance of Al 2 O 3 is preferably 1 μm or more and 3 μm or less, and the standard deviation is preferably 0.5 μm or more and 1.5 μm or less. By uniformly dispersing the binding phase, the effect of maintaining hardness and toughness in balance can be expected. If the distance between the particles exceeds 1 to 3 μm, the dispersion degree of the bound phase will vary, and defects will easily occur. The inter-particle distance refers to a person who sets one by one for each of the Al 2 O 3 particles. Any one of Al 2 O 3 particles of "distance between the particles' line from the center of gravity of Al 2 O 3 particles of Al and the other having a center of gravity of the nearest point of the position of the center of gravity of the 2 O 3 particles. The so-called "average distance between particles" refers to the average value of all the distances between particles. The ratio of the mass of O contained in the sintered body to the mass of C (O / C ratio) is preferably 0.015 or more and 0.061 or less. Within this range, Al 2 O 3 is uniformly dispersed and precipitated, and it is expected to satisfy [8] and [11]. The oxygen content in the sintered body is preferably from 0.1% by mass to 0.4% by mass. When the oxygen content is 0.1% by mass or less, there is a possibility that Al 2 O 3 is not precipitated and the hardness is not improved. When the oxygen content is 0.4% by mass or more, Al 2 O 3 may be aggregated and defects may easily occur. Therefore, when the oxygen content is within the above range, the effect of improving the hardness of the sintered body and the effect of suppressing the defects are expected. The lattice constant of the bonded phase is preferably 3.65 Å to 4.0 Å. When the lattice constant of the bonded phase is 3.65 Å or more, C dissolves and deforms, thereby maintaining high hardness at higher temperatures. When the lattice constant of the bonded phase is greater than 4.0 Å, the deformation becomes large, and cracks may occur in the bonded phase to cause defects. Therefore, when the lattice constant of the bonded phase is within the above range, the effect of maintaining the high hardness of the sintered body at a higher temperature and the effect of suppressing the defect of the sintered body are expected. The average particle diameter of the WC particles is preferably from 0.1 μm to 3 μm. When the average particle diameter is 0.1 μm or less, the toughness of the sintered body is reduced, and defects may occur. On the other hand, when the average particle diameter is 5 μm or more, the strength of the sintered body is reduced, and defects may easily occur. Therefore, when the average particle diameter of the WC particles is within the above range, the effect of suppressing the defect of the sintered body is expected. The content of the binding phase in the sintered body is preferably 2% by mass or more and less than 10% by mass. When the content of the bonded phase is less than 2% by mass, the toughness of the sintered body may be reduced, and defects may easily occur. When the content of the bonded phase is more than 10% by mass, the high-temperature hardness of the sintered body may be easily reduced. Therefore, when the content of the bound phase is within the above range, the effect of suppressing the loss of the sintered body and the effect of suppressing the reduction in the high-temperature hardness of the sintered body are expected. In addition, it was confirmed that the sintered body includes a hard phase (first hard phase and second hard phase), a bonded phase (alloy powder) and Al 2 O 3 , and a hard phase (first hard phase and second hard phase) and a bond. phase volume of Al 2 O 3 or the content of the distance, and the bond between WC particles (hard phase 1) the average particle diameter, a circle equivalent diameter of Al 2 O 3 particles or the like of the constituent phases. First, a sample including an arbitrary cross section of a sintered body is prepared. The profile can be produced using a focused ion beam device, an argon ion profile polisher device, and the like. Next, the processed cross-section was photographed at 10,000 times with a SEM (Scanning Electron Microscope) to obtain an electronic image with a field of view of 10 fields. Then, using the attached EPMA (Electron Probe Micro-Analysis: Electron Probe Micro-Analysis) or EDX (Energy Dispersive X-ray spectrometry), a specific area (12 μm × 9 μm) for elemental distribution analysis. Based on the obtained elemental distribution analysis, a region containing WC was taken as the first hard phase, and a region not including WC and included the first metal (Ni, Co) and the second metal (Al, W) and C was used as the binding phase. Let Al 2 O 3 be the region containing Al and O. Thereby, it was confirmed that the sintered body contains a hard phase (a first hard phase and a second hard phase), a bonded phase, and Al 2 O 3 . The composition of the bonded phase and the ratio (volume%) of the bonded phase in the sintered body were determined by elemental distribution analysis. Furthermore, depending on the sintering conditions, there may be voids other than the hard phase and the bonded phase. Furthermore, the image analysis software ("Mac-View I", manufactured by Mountain Tech Co., Ltd.) was used to calculate the equivalent diameter of a circle of Al 2 O 3 (the diameter of a virtual circle having the same area as the area of the particles) dispersed in the sintered body. ) And its standard deviation, and the average particle size of WC particles. In addition, each value is an average value of the results obtained by 10-field analysis. In addition, the composition of the compound particles constituting the hard phase (the first hard phase and the second hard phase), and the respective ratios (mass%) of the WC particles (the first hard phase) and the compound particles can be confirmed by crushing the The ICP emission spectrophotometry was used to determine the content ratio of each element in the pulverized material, and based on this, the composition ratio of each component was calculated on a trial basis. In addition, since the content ratio of WC particles in the sintered body is relatively high, there are many regions where WC particles are adjacent to each other. Adjacent WC particles can be distinguished from each other by the reflection electron image obtained from the element distribution analysis result and the SEM image. The reflected electron image is used to observe the color difference (darkness) due to the difference in crystal orientation of each WC particle. <Manufacturing of Sintered Body> In one embodiment of the present disclosure, first, the first metal (Co, Ni) and the second metal (Al, W) are used as raw materials, and atomization, arc dissolution, and plasma treatment are used. Make a binding phase. In addition, when producing a binder phase powder, in addition to the first metal (Co, Ni) and the second metal (Al, W), V, Ti, Nb, Ta, B, C, etc. may be added. The obtained combined phase is pulverized by, for example, a bead mill, a ball mill, a jet mill, or the like, to obtain a combined phase powder. The average particle diameter of the binder phase powder is preferably 0.3 to 3 μm. Examples of the beads / balls used in the bead mill / ball mill include aluminum, silicon nitride, and cemented carbide beads / balls having a particle diameter of 0.1 to 3 mm. Examples of the dispersion medium include ethanol, acetone, and liquid. Nitrogen and so on. The processing time of the bead mill / ball mill is, for example, 30 minutes to 200 hours. The slurry obtained from the bead mill / ball mill is dried, for example, in the atmosphere. When pulverized over time and dried in the atmosphere, thereby adsorbing oxygen in the air and sintering, the adsorbed oxygen reacts with Al in the binding phase to precipitate Al 2 O 3 . In addition, as another method, in the case of pulverization by a jet mill, air is used as a pulverizing gas source, and even if the pulverizing time is increased, a bonded phase powder that adsorbs oxygen can be obtained. As will be described later, a sintered body in which Al 2 O 3 is dispersed can be obtained even if Al 2 O 3 powder is directly added, but Al 2 O 3 is precipitated as in this method, and the particle size of Al 2 O 3 can be made finer and better. . Next, the obtained combined phase powder is mixed with a separately prepared WC particle powder by a mill, a ball mill, a mortar, and the like. In this case, an appropriate amount of C is added in consideration of the amount of C contained in the binding phase. Mixing is performed in an open state to the atmosphere. Thereby, oxygen is incorporated into the mixture. In order to uniformly disperse alumina (Al 2 O 3 ) in the sintered body (hard material) and to sufficiently and uniformly incorporate oxygen into the mixture, the mixing time is preferably 6 to 20 hours. Examples of the balls used in the ball mill include 3 mm diameter balls made of alumina, silicon nitride, or cemented carbide, and examples of the dispersion medium include ethanol, acetone, and liquid nitrogen. The processing time is, for example, 3 to 20 hours. A mixed powder is obtained by drying the slurry obtained by the mixing, for example, in the air. During mixing, as the Al 2 O 3 dispersed in the sintered body, a fine Al 2 O 3 powder (0.01 to 0.5 μm) may be added. The obtained mixed powder is put into, for example, a mold (Ta capsule or the like) made of cemented carbide, and pressed to obtain a press-formed body. The pressing pressure is preferably 10 MPa to 16 GPa, for example, 100 MPa. Next, the press-formed body was sintered in a vacuum. The sintering temperature is preferably 1000 to 1800 ° C. The sintering time is, for example, about 1 hour. Here, for example, it is controlled as follows: during sintering, the holding time at 400 ° C. is set to 30 minutes to 5 hours, so that C contained in the formed body is separated, and the mass of O contained in the final sintered body is relatively The mass ratio (C / O ratio) in C becomes an expected value. Thereby, the first hard phase (WC particles) and the bonded phase are densely sintered, and fine Al 2 O 3 is precipitated in the sintered body, so that a sintered body with improved abrasion resistance at high temperature can be formed. The cooling rate after sintering is, for example, 2 to 20 ° C / min. Thereby, a compound phase represented by the following formula is precipitated. (Co, Ni) x (Al, W) y C z [wherein (Co, Ni) is a first metal, (Al, W) is a second metal, and x, y, and z are atomic weight ratios. After that, for example, a hot isostatic pressing (HIP: Hot Isostatic Pressing) treatment is performed at 1400 ° C. and 1000 atm for 1 hour to obtain a sintered body (alloy). The average particle diameter of the WC particles is preferably 0.1 to 10 μm, and the content of the WC particles in the sintered body (hard material) is preferably 50 to 99% by volume. With such a particle size range and a composition range, the hardness of the obtained sintered body is expected to be further increased. The average particle diameter of the WC particles can be measured by a method using the above-mentioned element distribution analysis and image analysis software. In addition, the sintered body of this embodiment may contain unavoidable impurities (B, N, O, etc.) within a range that does not impair the effects of the present disclosure. In addition, the sintered body of this embodiment may include free carbon or an abnormal layer called an η phase in its structure. [Examples] Hereinafter, the present disclosure will be described in more detail with examples, but the present disclosure is not limited thereto. <Examples 1 to 50> A metal powder was mixed with a composition of 42.5Co-40Ni-10W-7.5Al (atomic%), and a bonded phase was produced by an atomization method. (The metal powders used in Examples 1 to 50 are all the same.) The obtained bonded phase was pulverized by a ball mill using a super hard ball having a particle size of 1 μm. The obtained slurry was dried in the air to obtain a combined phase powder. The obtained combined phase powder, the hard particles (the first hard phase and the second hard phase) of the composition described in Tables 1 and 2 and the carbon powder were put into a cemented carbide ball with a diameter of 3.5 mm and ethanol. Mix in an open air mill. The mixing time of the attritor is shown in Tables 1 and 2. The obtained slurry was dried in the air to obtain a mixed powder. The mixed powder was filled in a cemented carbide mold and pressed at a pressure of 100 MPa to obtain a press-formed body. This press-molded article was sintered at 1450 ° C for 1 hour under the sintering conditions described in Tables 1 and 2. At this time, by setting the holding time at 400 ° C in a hydrogen atmosphere as shown in Tables 1 and 2, the C contained in the formed body is detached, and the C / O ratio contained in the final sintered body is shown in Tables 3 and 4. Take control. The cooling rate was adjusted as described in Tables 1 and 2. Thereby, a compound phase represented by (Co, Ni) x (Al, W) y C z is precipitated. Thereafter, for example, a hot isostatic pressing (HIP: Hot Isostatic Pressing) treatment is performed for 1 hour under the conditions of 1400 ° C and 1000 atm to obtain a sintered body (hard material). <Comparative Example 1> When mixing with an attritor, the closed-type attritor was used to suppress the oxidation of the mixture. The slurry obtained after the mixing was dried in a nitrogen atmosphere. The sintering conditions were vacuum, 1450 ° C, and 1 hour. Table 2 shows the blending ratio and manufacturing conditions of the binding phase. Other points were the same as in Example 1 to obtain a sintered body. <Comparative Examples 2 to 3> The sintering conditions were set to vacuum and sintered at 1450 ° C for 1 hour. Table 2 shows the blending ratio and manufacturing conditions of the binding phase. Other points were the same as in Example 1 to obtain a sintered body. <Comparative Example 4> Instead of 42.5Co-40Ni-10W-7.5Al (atomic%) metal powder, 1.2 μm metal Co was used. Table 2 shows the blending ratio and manufacturing conditions of the binding phase. The other points were the same as in Comparative Example 1, and a sintered body was obtained. <Production of Cutting Tool> A sintered body (hard material) obtained in each of the above Examples and Comparative Examples was cut and finished by wire electrical discharge machining to produce a cutting tool having a nose R of 0.8 mm. [Table 1] [Table 2] <Evaluation of Cutting Tools> Inconel (registered trademark) 718 (product name, manufactured by Inconel) was used as the material to be cut for each of the cutting tools produced in the examples and comparative examples described above under the following cutting conditions. The cutting test was performed on an NC lathe, and the abrasion amount (μm) and boundary abrasion amount (μm) of the retraction surface of the cutting tool after cutting 0.2 km were measured (see FIG. 1). Cutting speed: 50 m / min. Notch amount: 0.2 mm. Delivery amount: 0.1 mm / rev. Cutting oil: <Evaluation of physical properties of sintered body.> It is determined that the sintered body contains a hard phase (the first hard phase) in the same manner as described in the above embodiment. And the second hard phase), the combined phase (alloy powder) and Al 2 O 3 , and the hard phase (the first hard phase and the second hard phase), the volume content of the combined phase or Al 2 O 3 , and the ratio of the combined phase Composition etc. The amount of oxygen and the amount of C in the sintered body were pulverized and measured by ICP emission spectrometry. The lattice constant of the bound phase is specified by EDS analysis and electron diffraction image of the selected area observed by TEM. As the TEM, JEM-2100F / Cs (manufactured by Japan Electronics Co., Ltd.) was used. As the Cs collector, CESCOR (manufactured by CEOS) was used. As the EDS machine, a JED2300 series dry SD60GV detector (manufactured by Japan Electronics Co., Ltd.) was used. TEM observation conditions were set as follows: acceleration voltage: 200 kV, probe size: 0.13 nm. [table 3] * 1 Boundary abrasion is the part where the abrasion becomes large due to the decrease in strength, defects, or ion shedding. [Table 4] * 2 The measurement cannot be performed due to the defect of the cutter head. * 3 The measurement cannot be performed due to the defect of the cutter head. * 4 The measurement cannot be performed due to the defect of the cutter head. * 5 The test head was absent at the point of cutting 0.1 km, so the test was suspended. From the results shown in Tables 3 and 4, it can be seen that the cutting tools of Examples 1 to 50, which are cutting tools of the present disclosure, have improved wear resistance at high temperatures. From the results of Examples 1 to 10, it can be seen that the bonded phase contains the formula: (Co, Ni) x (Al, W) y C z [wherein (Co, Ni) is the first metal and (Al, W) Is a second metal, and x, y, and z are atomic weight ratios. ] In the case of the compound phase represented by the above formula, x is 60 atomic% to 95 atomic%, y is 4 atomic% to 32 atomic%, and z is 0.3 atomic% to 15 atomic%. Consumption is further improved. It is also known that when x is 75 atomic% or more and 93 atomic% or less, y is 5 atomic% or more and 20 atomic% or less, and z is 0.5 atomic% or more and 10 atomic% or less, the wear resistance at high temperature is further improved. It is also known that when x is 80 atomic% or more and 90 atomic% or less, y is 6 atomic% or more and 12 atomic% or less, and z is 1 atomic% or more and 5 atomic% or less, the abrasion resistance at high temperature is most improved. From the results of Examples 11 and 12, it can be seen that even when the sintered body includes the second hard phase, when the volume ratio of the first hard is larger than that of the second hard phase, the wear resistance at high temperature is still improved. From the results of Example 50, it can be seen that the abrasion resistance at a higher temperature is improved when the second hard phase is included than when the second hard phase is not included. From the results of Examples 13 and 14, it is considered that if the content of Al 2 O 3 in the sintered body is too small, the effect of improving the wear resistance at high temperature may not be obtained. On the other hand, from the results of Examples 48 and 49, if the content ratio of Al 2 O 3 in the sintered body is too large, the strength of the sintered body is reduced, and defects are liable to occur. From the results of Examples 15 to 17, it is considered that since Al 2 O 3 is relatively fine, the effect of further improving the hardness of the sintered body is expected. On the other hand, if Al 2 O 3 is too fine, the toughness of the sintered body is improved. Reduce, easy to produce defects. On the other hand, from the results of Examples 43 to 47, if the diameter of Al 2 O 3 is too large, the strength of the sintered body is reduced, and defects are liable to occur. From the results of Examples 18 and 19, it is considered that if the inter-particle distance of Al 2 O 3 contained in the sintered body is too small, the degree of dispersion of the binding phase is biased, and defects are liable to occur. On the other hand, from the results of Examples 41 and 42, it is considered that if the inter-particle distance of Al 2 O 3 contained in the sintered body is too large, the strength of the sintered body is reduced and defects are liable to occur. From the results of Examples 20 and 21 and the results of Examples 22 and 23, it is considered that the ratio of the mass of O contained in the sintered body to the mass of C (O / C ratio) is too small, and the oxygen content in the sintered body ( When the amount of oxygen alloy is too small, the wear resistance at high temperatures is reduced because Al 2 O 3 is too small. On the other hand, from the results of Examples 37 and 38 and the results of Examples 39 and 40, when the oxygen content (amount of oxygen alloy) in the sintered body is too large, the mass of O contained in the sintered body is relative to When the mass ratio of C (O / C ratio) is too large, Al 2 O 3 aggregates and defects are likely to occur. From the results of Examples 24 and 25, if the lattice constant of the bonded phase is small, the abrasion resistance at high temperatures is reduced. On the other hand, from the results of Examples 35 and 36, it is considered that if the lattice constant of the bonded phase is too large, the deformation due to the solid solution of C becomes large, and cracks occur in the bonded phase and defects are easily generated. From the results of Examples 26 and 27, if the average particle diameter of the WC particles is small, the toughness of the sintered body is reduced, and defects are liable to occur. On the other hand, from the results of Examples 33 and 34, if the average particle diameter of the WC particles is too large, the strength of the sintered body is reduced, and defects are liable to occur. From the results of Examples 28 to 32, it is considered that if the content of the binding phase is too small, the toughness of the sintered body is reduced, and defects are liable to occur. On the other hand, if the content of the binding phase is too large, the high-temperature hardness of the sintered body is likely to decrease. I should understand that all aspects of the embodiments and examples of this disclosure are illustrative and not restrictive. The scope of the present disclosure is shown by the scope of the patent application rather than the above-mentioned embodiments, and covers all changes within the meaning and scope equivalent to the scope of the patent application.