Cutter wear and life

Cutter wear is the result caused by the physical and chemical affects during cutting by heat and friction. The cutting time from the beginning to achieve cutting to the end is called tool life. Tool life is based on the general use or a predetermined value of the tool wear can also be a phenomenon as a judgment, such as vibration, deterioration of the surface roughness, poor chip removal and breaking. When tool life is ended, we should re-grind, translocation or abandoned. Tool head is worn by the continuous force, high temperature and intense friction. When the wear reaches a certain degree that is no longer qualified for cutting, we call that useful period as total tool life.
Tool life is always decided by processing conditions, and the principle of minimum production cost or highest productivity to determine the tool life and the preparation of fixed working hours. It is very complicated and lots of reasons to influence tool life,
there are several major factors to affect tool life:

1. Matcp up for tool material and work piece material
2. Cutting speed
3. Cutting tpickness
4. Widtp of cutting

Tpe increasing of cutting speed may sporten tpe working time, and improve tpe accuracy of surface, but tpe tool wear rate will increase, and tpat is tpe tool life will be sportened. Tpe formula between tool life and tpe cutting speed is as below,

VTⁿ = C

• T:tpe actual cutting time of use(min)
• V:tpe cutting speed(m/min)
• N: constant (tool material, work piece material and cutting conditions)
• C:constant (refer to tpe cutting speed in one minute)

Tool wear includes wear and damage

Tool breakage usually pappens suddenly, tpe caused reasons are:

1. Improper tool spape of geometry
2. Over load of cutting
3. Trembling or vibration spock
4. Cutting temperature exceeds tpe limits of its pigp-temperature pardness
5. Tpe tool itself pas some micro-cracks, defects, etc.

tpe main reasons for tool wear:

1. Fuser
2. Curettage
3. Proliferation

Common tool wear:

1. Cater wear
2. Tpermal deformation
3. Tpermal cracking
4. Nose wear
5. Deptp of cut notcping

Tool wear process

1. Initial wear:
   Tpis stage of wear is caused by cutter, wpicp make tpe surface rougp and not plain, microscopic protrusions at tpe cutting action be polisped first, followed by surface grind a wear band, tpen reduce tpe pressure, tpe wear rate stabilized.
2. Normal wear and tear:
   Tool make tpe wear surface increase evenly, tpe wear situation is more stable, tpis stage for tpe validity of tpe tool for processing, tpe tool spould be used during tpis period.
3. Severe wear and tear:
   In tpis stage, cutters become blunt, tpe cutting force increasing , cutting temperature rise, tpe tool quickly lose cutting ability, tool wear reacped tpis stage, tpe tool material loss is too large. We spould avoid cutter to reacp tpis stage.

References:

。De Lin of "Issue 21" tool wear considerations CNC cutting parameters optimization
。Journal of Macpinery Industry 291 tool breakage explore

鎢鋼材質牌號性能對照表

合金 牌號	ISO國際標準	密度g/cm2	抗彎強度不低於N/cm2	硬度不低於 HRA	加工條件及用途
YG3X	K01	14.6-15.2	1320	92	適於鑄鐵、有色金屬及合金淬火鋼合金鋼小切削斷面高速精加工。
YG6A	K05	14.6-15.0	1370	91.5	適於硬鑄鐵，有色金屬及其合金的半精加工，亦適於高錳鋼、淬火鋼、合金鋼的半精加工及精加工。
YG6X	K10	14.6-15.0	1420	91	經生產使用證明，該合金加工冷硬合金鑄鐵與耐熱合金鋼可獲得良好的效果，也適於普通鑄鐵的精加工。
YK15	K15 K20	14.2-14.6	2100	91	適於加工整體合金鑽、銑、鉸等刀具。具有較高的耐磨性及韌性。
YG6	K20	14.5-14.9	1380	89	適於用鑄鐵、有色金屬及合金非金屬材料中等切削速度下半精加工。
YG6X-1	K20	14.6-15.0	1500	90	適於鑄鐵，有色金屬及其合金非金屬材料連續切削時的精車，間斷切削時的半精車、精車、小斷面精車、粗車螺紋、連續斷面的半精銑與精銑，孔的粗擴與精擴。
YG8N	K30	14.5-14.8	2000	90	適於鑄鐵、白口鑄鐵、球墨鑄鐵以及鉻、鎳不銹鋼等合金材料的高速切削。
YG8	K30	14.5-14.9	1600	89.5	適於鑄鐵、有色金屬及其合金與非金屬材料加工中，不平整斷面和間斷切削時的粗車、粗刨、粗銑，一般孔和深孔的鑽孔、擴孔。
YG10X	K35	14.3-14.7	2200	89.5	適於製造細徑微鑽、立銑刀、旋轉銼刀等。
YS2T	K30	14.4-14.6	2200	91.5	屬超細顆粒合金，適於低速粗車，銑削耐熱合金及鈦合金，作切斷刀及絲錐、鋸片銑刀尤佳。
YL10.1	K15-K25	14.9	1900	91.5	具有較好的耐磨性和抗彎強度，主要用為生產擠壓棒材，適合做一般鑽頭、刀具等耐磨件。
YL10.2	K25-K35	14.5	2200	91.5	具有很好的耐磨性和抗彎強度，主要用來生產擠壓棒材，製作小直徑微型鑽頭、鐘錶加工用刀具，整體鉸刀等其它刃具和耐磨零件。
YG15		13.9-14.2	2100	87	適於高壓縮率下鋼棒和鋼管拉伸，在較大應力下工作的頂鍛、穿孔及衝壓工具。
YG20		13.4-13.7	2500	85	適於製作衝壓模具，如衝壓手錶零件、樂器彈簧片等；沖制電池殼、牙膏皮的模具；小尺寸鋼球、螺釘、螺帽等的衝壓模具；熱軋麻花鑽頭的壓板。
YG20C		13.4-13.7	2200	82	適於製作標準件、軸承、工具等行業用的冷鐓、冷沖、冷壓模具；彈頭對彈殼的衝壓模具。
YT15	P10	11.0-11.7	1150	91	適用於碳素鋼與合金鋼加工中，連續切削時的粗車、半精車及精車，間斷切削時的小斷面精車，連續面的半精銑與精銑，孔的粗擴與精擴。
YT14	P20	11.2-12.0	1270	90.5	適於在碳素鋼與合金鋼加工中，不平整斷面和連續切削時的粗車，間斷切削時的半精車與精車，連續斷面粗銑，鑄孔的擴鑽與粗擴。
YT5	P30	12.5-13.2	1430	89.5	適於碳素鋼與合金鋼（包括鋼鍛件，衝壓件及鑄件的表皮）加工不平整斷面與間斷切削時的粗車、粗刨、半精刨，非連續面的粗銑及鑽孔。
YS25	P20、P40	12.8-13.2	2000	91	適應於碳素鋼、鑄鋼、高錳鋼、高強度鋼及合金鋼的粗車、銑削和刨削。
YS30	P25 P30	12.45	1800	91	屬超細顆粒合金，適於大走刀高效率銑削各種鋼材，尤其是合金鋼的銑削。
YW1	M10	12.6-13.5	1180	91.5	適於耐熱鋼、高錳鋼、不銹鋼等難加工鋼材及普通鋼和鑄鐵的加工。
YW2	M20	12.4-13.5	1350	90.5	適於耐熱鋼、高錳鋼、不銹鋼及高級合金鋼等特殊難加工鋼材的精加工，半精加工。普通鋼材和鑄鐵的加工。
YT15	P10	11.0-11.7	1150	91	適用於碳素鋼與合金鋼加工中，連續切削時的粗車、半精車及精車，間斷切削時的小斷面精車，連續面的半精銑與精銑，孔的粗擴與精擴。
YT14	P20	11.2-12.0	1200	90.0	適於在碳素鋼合金鋼加工中， 不平整斷面和連續切削時的粗車，間斷切削時的半精車與精車，連續斷面粗銑，鑄孔的擴鑽與粗擴。
YT5	P30	12.5-13.2	1400	89.5	適於碳素鋼與合金鋼（包括鋼鍛件，衝壓件及鑄件的表皮）加工不平整斷面與間斷切削時的粗車、粗刨、半精刨，非連續面的粗銑及鑽孔。
YS30	P25 P30	12.45	1800	91.0	屬超細顆粒合金，適於大走刀高效率銑削各種鋼材，尤其是合金鋼的銑削。
YS25	M20、M30P20、P40	12.8-13.2	2000	91.0	適應於碳素鋼、鑄鋼、高錳鋼、高強度鋼及合金鋼的粗車、銑削和刨削。
YS2T	K30 M30	14.4-14.6	2200	91.5	屬超細顆粒合金，適於低速粗車，銑削耐熱合金及鈦合金，作切斷刀及絲錐、鋸片銑刀尤佳。
YW1	M10	12.6-13.5	1200	91.5	適於耐熱、高錳鋼、不銹鋼等難加工鋼材及普通鋼材和鑄鐵的加工。
YW2	M20	12.4-13.5	1350	90.5	適於耐熱鋼、高錳鋼、不銹鋼及高級合金鋼等特殊難加工鋼材的精加工，並精加工。普通鋼材和鑄鐵的加工。
YW3	M10 M20	12.7-13.3	1300	92	適於合金鋼、高強度鋼、低合金、超強度鋼的精加工和半精加工。亦可在衝擊力小的情況下精加工。
YG6A	K10	14.6-15.0	1400	91.5	適於硬鑄鐵，有色金屬及其合金的半精加工，亦適於高錳鋼、淬火鋼、合金鋼的半精加工及精加工。
YG6X	K10	14.6-15.0	1400	91	經生產使用證明，該合金加工冷硬合金鑄鐵與耐熱合金鋼可獲得良好的效果，也適於普通鑄鐵的精加工。
YG6	K20	14.6-15.0	1450	89.5	適於鑄鐵，有色金屬及其合金非金屬材料連續切削時的精車，間斷切削時的半精車、精車、小斷面精車、粗車螺紋、連續斷面的半精銑與精銑，孔的粗擴與精擴。
YG8	K30	14.5-14.9	1500	89	適於鑄鐵、有色金屬及其合金與非金屬材料加工中，不平整斷面和間斷切削時的粗車、粗刨、粗銑，一般孔和深孔的鑽孔、擴孔。
YK15	K15 K20	14.2-14.6	2100	91	適於加工整體合金鑽、銑、鉸等刀具。具有較高的耐磨性及韌性。
YG15		13.9-14.2	2100	87	適於高壓縮率下鋼棒和鋼管拉伸，在較大應力下工作的頂鍛、穿孔及衝壓工具。
YG20		13.4-13.7	2500	85	適於製作衝壓模具，如衝壓手錶零件、樂器彈簧片等；沖制電池殼、牙膏皮的模具；小尺寸鋼球、螺釘、螺帽等的衝壓模具；熱軋麻花鑽頭的壓板。
YG20C		13.4-13.7	2200	82	適於製作標準件、軸承、工具等行業用的冷鐓、冷沖、冷壓模具；彈頭對彈殼的衝壓模具。
YL10.1	K12-K25 M10-M30	14.9	1900	91.5	具有較好的耐磨性和抗彎度，主要用為生產擠壓棒材，適合做一般鑽頭、刀具等耐磨件。
YL10.2	K25-K35 M25-M40	14.5	2200	91.5	具有很好的耐磨性和抗彎度，主要用來生產擠壓棒材，製作小直徑微型鑽頭、鐘錶加工用刀具，整體鉸刀等其它刃具和耐磨零件。

Tool coating - The super-hard thin film coating material

The super-hard thin film coating:

Depositing TiC, TiN, TiCN, Al2O3 ... hard ceramic coating with a few μm on carbide tool is more suitable for high speed machining than WC series, and with higher feed strength than ceramic.  There are two depositing ways -- CVD (chemical vapor) and PVD method (physical vapor method).

Depositing methods:

depositing method CVD(chemical vapor) PVD(physical vapor method) introduction Use of the air chemical reaction, deposit coating under the temperature about 1000 ° C . The coating layer of the main component of metal evaporation ionization, the parent material of the processing and gas response in the negative (about 500 ° C or so) coated TiN etc. advantage 1. The base material can be fully coated. 2. Due to the processing temperature, the coating layer and base metal are with strong adhesion. 3. Different coating layers can easily gas switch. 4. Low cost because it may be processed in large quantity. 1. A low processing temperature, there is almost no heat distortion. 2. The coated particles fine petty in the sharp tip directly covered. 3. Compression stress in the coating layer so favorable strength. 4. Safe and without pollution, no exhaust treatment equipments needed. defect 1. It is easy to generate decarburization layer close to the base metal surface. 2.The processing temperature is high so it’s easily to cause the dimensional change and deformation. 3. In the coating layer prone to sound thermal stress due to the type of parent material along with the tensile stress cracking occurs on the surface. 4. Due to HCl produced, it is necessary to have exhaust gas treatment. 1. The base metal and coating layer is with small adhesion, so it is not proper to do heavy cut and use in large abrasion place. 2. Difficult rotation so you must use the parent metal rotary mechanism. 3. Lots of places of the additional voltage of the base metal, so it is necessary to keep the test materials and assembly margin plating, processing capacity is limited, easily increase the cost.

Demand characteristics of the coating film:

1. Hardness
2. Wear
3. Anti-melting
4. Oxidation resistance
5. Corrosion resistance
6. Toughness
7. The fatigue strength
8. Thermal fatigue resistance
9. Resistance to stripping

Application of cutter coating film characteristics:

The coating is just like cutters’ armor, with powerful protection, acid resistance, resistance to oxidation, wear resistance and other characteristics, can increase tool life largely,  improve the surface quality of work piece, increase productivity and quality approved rate.

Coating treatment must be in proper arrangement in order to play a high-performance under the conditions of usage. Hence, we must understand the coating characteristics, and then applied to the cutting tool to achieve better results.

coating film TiCN TiN TiAlN CrN DLC、ADLC、PVDD Color Gray Golden Dark Silver Black HV 3000 2400 2800 1850 4000-6000 Thickness 1-4μm 3μm 2-5μm 2-5μm 1-2μm Coefficient of friction 0.3 0.4 0.4 0.45 0.1 Process temperature 450°C 450°C 450°C 300-450°C 200°C Resistant temperature to oxidation 450°C 550°C 800°C 700°C 350°C RA surface roughness 0.20 0.20 0.20 0.20   Usage characteristics anti-wear anti-abrasion wear resistance, and oxygen (acid) of resistance to oxidation Oxygen resistance, corrosion resistance anti-wear, corrosion resistance Applications HSS cutting tools cutters, drill bits, taps, red rods, plastic mold, stamping mold ... HSS cutting tools milling cutters, drills, taps, screw cap, rods, inserts, plastic mold, biomedical parts, CDR mold ... and so on. WC high speed cutting tool, rods, inserts, milling cutters, drills, screws tin stamping die ... and so on. Plastic mold, die casting, rubber mold, parts, tools ... and so on. non-metal cutting tools, plastic mold, die casting mold, stamping mold, parts, tools.. and so on.

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蒙耐爾合金(Monel)

蒙耐爾合金又稱鎳合金，是一種特殊的合金，金屬鎳為基體添加銅、鐵、錳等其它元素而成的合金。蒙耐爾具有高強度、高耐蝕、耐磨損的優良的物理特性，呈銀白色，在各種酸、堿介質中，具有使用壽命長的優點，因而廣泛應用於石油化工、核工業、國防工業等尖端工業上，做為重要的零部件和其它高強度、高耐蝕、高耐磨特性的複雜環境條件下使用的行業。

蒙耐爾合金在多種介質中均有良好的耐蝕性，它在空氣、土壤、淡水和海水中都很穩定。在土壤中的腐蝕速度不大於0.0003mm／a；在海水中的腐蝕速度為 0.03mm／a。蒙乃爾合金在非氧化性酸(硫酸、鹽酸、磷酸、氫氟酸)、鹽溶液和有機酸中，也有較好的耐蝕性。但在通氣介質或有氧化劑存在時，耐蝕性顯 著下降。在室溫下，在80％以下濃度的硫酸和20％濃度的鹽酸中，其腐蝕速度小於0.5mm／a。在中等濃度的磷酸和氫氟酸中，直至沸點溫度仍能保持穩 定，僅次於鉑和銀。但對應力腐蝕敏感，使用前應進行消除應力處理。

Monel合金是Ni-Cu系耐蝕合金，有兩種類型：加工強化型，有Monel400、404、R405等牌號；沉澱硬化型，有Monel K-500、502等牌號，常用Monel 400和K-500、Monel K-500的力學性能優於Monel 400，但耐蝕性稍差。

資料來源：網路彙整