隨著科技的發展使得當今大量零部件的結構異形化、形狀復雜化及型面多樣化，如鈦合金的整體葉輪、航空發動機的渦輪盤。難加工材料如奧氏體不銹鋼、淬火鋼、鈦合金、高溫合金和鈦合金等材料，一方面由于難加工材料硬度高、熔點高、耐磨性好、抗氧化和抗腐蝕能力強等優點，所以其在航空航天和石油化工等領域應用廣泛；另一方面
傳統材(cai)(cai)料(liao)(liao)(liao)的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)工(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)、加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)方法和加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)刀(dao)具(ju)無法滿足(zu)難加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)材(cai)(cai)料(liao)(liao)(liao)結(jie)構件的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)要求(qiu)，需要從(cong)難加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)材(cai)(cai)料(liao)(liao)(liao)及其(qi)結(jie)構件的(de)(de)(de)(de)可(ke)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)性和加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)工(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)方法出發(fa)，提出合(he)理的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)方法：采用(yong)相(xiang)位圖方法分析難加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)材(cai)(cai)料(liao)(liao)(liao)的(de)(de)(de)(de)可(ke)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)性；選取適合(he)的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)工(gong)(gong)(gong)(gong)(gong)藝(yi)(yi)方法--高(gao)(gao)壓冷卻(que)方法，微量潤滑切(qie)(qie)削（MQL）加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)，加(jia)(jia)(jia)(jia)熱（激光(guang)）輔助切(qie)(qie)削加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)，低(di)溫冷卻(que)輔助切(qie)(qie)削加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)；還有提高(gao)(gao)難加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)材(cai)(cai)料(liao)(liao)(liao)切(qie)(qie)削效率(lv)的(de)(de)(de)(de)方法：刀(dao)具(ju)設計、刀(dao)具(ju)涂層和材(cai)(cai)料(liao)(liao)(liao)、刀(dao)具(ju)幾何(he)參數的(de)(de)(de)(de)合(he)理選擇、選取合(he)理的(de)(de)(de)(de)切(qie)(qie)削用(yong)量和加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)方式。針對難加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)材(cai)(cai)料(liao)(liao)(liao)的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)可(ke)以參照一(yi)些廠家(jia)的(de)(de)(de)(de)加(jia)(jia)(jia)(jia)工(gong)(gong)(gong)(gong)(gong)方案。
本文主要(yao)討論難加工材(cai)(cai)料需要(yao)考慮(lv)的4個要(yao)點(dian)：用(yong)合理(li)的刀(dao)具幾(ji)何(he)參數和切削參數來(lai)控制切削力、冷卻潤(run)滑輔助工藝(yi)、合理(li)的加工工藝(yi)和考慮(lv)刀(dao)具性價比的合理(li)刀(dao)具效(xiao)率(lv)。并列(lie)舉幾(ji)個提高難加工材(cai)(cai)料的加工效(xiao)率(lv)和刀(dao)具使用(yong)壽命的解(jie)決方案(an)。
1.
（1）適當地控制刀具的切(qie)削力
切(qie)(qie)(qie)削力的(de)(de)(de)方向和大小直接影響(xiang)刀(dao)具(ju)的(de)(de)(de)使(shi)用壽(shou)命(ming)及(ji)工(gong)件（尤其(qi)是薄壁件）的(de)(de)(de)加工(gong)質量。切(qie)(qie)(qie)削參(can)數對(dui)切(qie)(qie)(qie)削力的(de)(de)(de)影響(xiang)如(ru)圖1所示，山(shan)(shan)高(gao)(gao)推(tui)出的(de)(de)(de)計算主切(qie)(qie)(qie)削力的(de)(de)(de)Kienzle定律，橫向為(wei)進給量或切(qie)(qie)(qie)深(shen)，縱向為(wei)切(qie)(qie)(qie)削力。進給量比切(qie)(qie)(qie)削深(shen)度對(dui)切(qie)(qie)(qie)削力的(de)(de)(de)影響(xiang)更顯(xian)著，如(ru)山(shan)(shan)高(gao)(gao)刀(dao)具(ju)公司整體合(he)金銑刀(dao)研發出專(zhuan)用于高(gao)(gao)溫合(he)金、鈦合(he)金及(ji)不(bu)銹鋼等材料的(de)(de)(de)高(gao)(gao)效刀(dao)具(ju)，既提高(gao)(gao)了加工(gong)效率和刀(dao)具(ju)使(shi)用壽(shou)命(ming)，又能降低加工(gong)風險(xian)，保證(zheng)零件的(de)(de)(de)加工(gong)質量。
圖1 切削參數對切削力的影響
（2）合理的(de)輔助加工工藝措施
加工難加工材料時，適當地提高加工線速度并實施充分的冷卻，能夠有效
（3）選用高效(xiao)加工(gong)方(fang)法加工(gong)難加工(gong)材料
目前常用的幾種高效加(jia)工(gong)方(fang)法有(you)：片(pian)皮法(fa)、層切法(fa)、擺線法(fa)及插銑法(fa)等(deng)。如采用(yong)片皮(pi)法大切(qie)深(shen)小(xiao)切(qie)寬的(de)(de)方式，盡可能地(di)使(shi)刀(dao)具(ju)少處在產生熱(re)量區域(yu)內而多處于散熱(re)區域(yu)，以提高刀(dao)具(ju)使(shi)用(yong)壽命。無論(lun)采用(yong)哪種方法，其目的(de)(de)都是在加工(gong)(gong)過程(cheng)中減(jian)少加工(gong)(gong)熱(re)的(de)(de)產生。難加工(gong)(gong)材料的(de)(de)高效加工(gong)(gong)方法會顯著地(di)影響刀(dao)具(ju)的(de)(de)加工(gong)(gong)效率和刀(dao)具(ju)使(shi)用(yong)壽命。
（4）刀(dao)具性價比的均(jun)衡
很多人(ren)都很看重刀具(ju)的(de)(de)價(jia)格及使用壽命而往(wang)(wang)往(wang)(wang)忽視了刀具(ju)的(de)(de)效(xiao)率(lv)問(wen)題，然而刀具(ju)效(xiao)率(lv)的(de)(de)提升(sheng)所節(jie)約下來(lai)的(de)(de)成(cheng)(cheng)本(ben)(ben)遠遠大于(yu)刀具(ju)自身的(de)(de)成(cheng)(cheng)本(ben)(ben)。圖(tu)2所示(shi)是(shi)切削速度與刀具(ju)成(cheng)(cheng)本(ben)(ben)、機床(chuang)成(cheng)(cheng)本(ben)(ben)、總加(jia)(jia)工(gong)成(cheng)(cheng)本(ben)(ben)和每(mei)小時加(jia)(jia)工(gong)零件數的(de)(de)關系圖(tu)，從圖(tu)2中可以(yi)看出，既保(bao)證加(jia)(jia)工(gong)效(xiao)率(lv)（每(mei)小時加(jia)(jia)工(gong)零件數），又兼顧其他(ta)成(cheng)(cheng)本(ben)(ben)時，加(jia)(jia)工(gong)需要選取合理的(de)(de)加(jia)(jia)工(gong)速度。
圖2 切削速度對加工成本影響圖
2.難加工材料的(de)加工實例
實例1：采用(yong)刀具涂(tu)層和高(gao)壓冷卻進行鈦(tai)合金的銑削。
對Ti6Al4V材料機匣件在200 bar情況下的加工案例，加工條件如下：刀桿型號為 R220.69-0040-12-5，F40M涂層，其刀片型號為XOEX120416R-M07/XOMX120416R-ME08；切削參數： fz= 0.14mm/z， ap =2mm，ae= 15mm，10 bar高壓冷卻。機匣件如圖3所示，材料為Ti6Al4V。刀具涂層如圖4所示，包括有TiN、（Ti，Al）N、Ti(C，N)和TiN結合涂層。切削速度對刀具使用壽命的影響如圖5所示，縱向為刀具連續切削時間，橫向為切削
圖3 機匣件
圖4 刀具涂層示意圖
圖5 切削速度對刀具壽命影響
實例2：新型銑(xian)刀高進給銑(xian)削的(de)應用。
（1）采用(yong)較小的軸向(xiang)切(qie)削深(shen)度，較大的每(mei)齒進給量(liang)（尤其對于(yu)加工(gong)大懸伸深(shen)模腔(qiang)時，傳統圓刀(dao)片銑刀(dao)軸向(xiang)切(qie)深(shen)不大），實際金(jin)屬切(qie)除(chu)率明(ming)顯提高，比用(yong)傳統圓刀(dao)片加工(gong)效(xiao)率高。
（2）新型銑(xian)(xian)刀(dao)(dao)與圓片銑(xian)(xian)刀(dao)(dao)的總切削(xue)(xue)力方向(xiang)如圖6所示，該(gai)種新型銑(xian)(xian)刀(dao)(dao)的總切削(xue)(xue)力的軸(zhou)向(xiang)分力較大(da)，提(ti)高(gao)(gao)刀(dao)(dao)具切削(xue)(xue)剛性，尤其當加工(gong)(gong)大(da)懸伸深(shen)模腔時，加工(gong)(gong)穩定(ding)性比傳統(tong)圓刀(dao)(dao)片銑(xian)(xian)刀(dao)(dao)好。山高(gao)(gao)新產品軸(zhou)向(xiang)切削(xue)(xue)深(shen)度(du)高(gao)(gao)達1.8mm。
新型(xing)(xing)銑(xian)刀加工模(mo)具型(xing)(xing)腔如圖7所示。加工要求、條件及狀態：加工模(mo)具型(xing)(xing)腔，預硬模(mo)具鋼(gang)56HRC；刀杠型(xing)(xing)號為R217.21-2525.0-R100.3 (Ф25 mm)；刀片型(xing)(xing)號：218.19-100T-T3-MD06，F15M；切削參(can)數(shu)：Vc=195m/min， N=2 500r/min，fz=0.53mm/z，Vf = 4 000mm/min，ap=0.3mm。
圖6 新型銑刀與圓片銑刀的總切削力方向
圖7 新型銑刀加工模具型腔
3.結論
難加工材料的機械特性決定了其可加工性差的特點。可采用選配適合的刀具和加工參數降低切削力。采用高壓冷卻的輔助加工工藝，選用適合的高效加工方法，考慮刀具性價比均衡優化等要素，可提高難加工
內容摘自金屬(shu)加工冷加工2015年第14期