Metal processing is inseparable from the blade. A good blade must have high wear resistance, long tool life, high metal removal rate and high reliability. It is even required to have high performance in dry cutting or wet cutting under severe conditions (such as complex cutting and deep cavity), so as to ensure small tolerance of workpiece size and excellent surface quality. Today, let’s take a look at how the leader of the blade industry produces blades

How to make blade tolerance accurate

A typical blade is made of 80% tungsten carbide and metal matrix. The function of metal matrix is to bond hard cemented carbide powder together, of which cobalt is the most common. The process of producing blades is very complex. It takes more than two days to complete, and there will be a lot of challenges. In addition to absolute precision and reliability, cleanliness is a prerequisite. The whole process must be well guaranteed without any carelessness.

第一步是確保每種特定粉末的組成比例恰到好處。鎢是一種源自山特維克在奧地利的礦山或回收刀片的有限原材料。鈷、鈦和所有其他成分均來自精心挑選的供應(yīng)商，這些供應(yīng)商可以確保始終如一的質(zhì)量，而不會影響成品的質(zhì)量。盡管如此，每批產(chǎn)品都必須在實驗室進(jìn)行嚴(yán)格的安全測試。然后將主要成分自動分配到稱重線沿線不同站點的容器中。對于某些刀片，需要手動添加少量特殊成分。經(jīng)過所有不同的站點后，整個集裝箱將重達(dá)數(shù)百公斤。

下一步是研磨，將容器中的成分與乙醇、水和有機(jī)化合物混合，研磨至所需粒徑：通常為0.1~5微米直徑。這個過程需要8~55小時，取決于成品的配方。該化合物是一種灰色漿液，其稠度類似于酸奶飲料。然后將漿料泵入噴霧干燥器，噴霧干燥器用熱氮氣蒸發(fā)乙醇和水的混合物。

當(dāng)粉末干燥時，它由直徑約 100 微米的球形顆粒組成。樣品被送到實驗室進(jìn)行質(zhì)量檢驗。然后，將制成的粉末裝入較小的桶中，通過壓制機(jī)加工，其中有機(jī)化合物作為粘合劑，壓制后粉末粘合在一起。特定刀片的模具到位后，模具的內(nèi)腔將充滿粉末。該機(jī)床在制造單個刀片時可以施加50噸的壓力。即使整個過程的自動化程度很高，每個刀片仍然會被稱重，然后操作人員會在一定的時間間隔進(jìn)行外觀控制，以確保最高的質(zhì)量和準(zhǔn)確性。在這個階段，刀片還很脆弱，所以下一步就是進(jìn)入燒結(jié)爐。

Why is sintering a complicated process

燒結(jié)爐一次可以燒結(jié)數(shù)千個刀片。刀片被加熱到1500℃左右，這個過程大約需要13個小時，壓粉被熔化成硬質(zhì)合金，這是一種極硬的材料。但是，這個過程會導(dǎo)致嚴(yán)重的收縮：燒結(jié)刀片的尺寸只有壓制零件尺寸的一半左右。再次送實驗室進(jìn)行質(zhì)檢后，將刀片的頂部和底部研磨至正確的厚度。由于硬質(zhì)合金非常堅硬，因此需要使用含有 1.5 億個工業(yè)金剛石小顆粒的砂輪將其磨削到正確的厚度。通常，刀片必須再次拋光以達(dá)到其精確的凹槽形狀和尺寸。

This is a key step in the manufacturing process. The use of 6-axis grinder can ensure very strict tolerance, so that there has been a joke in Kimmer factory: “if you sneeze, the tolerance will change immediately”.

Clean and coat the blade immediately after grinding. To avoid any grease or dust, gloves must be worn when taking the blade. There are two different coating methods of blade coating: chemical vapor deposition (CVD) and physical vapor deposition (PVD). In a typical CVD, the blade substrate is contacted with one or more volatile coating gases, which react on the surface of the blade substrate to generate the required deposits. The physical vapor depositio