Contrary to popular terminology, metal is not “cut” as much as it is a “forced separation from itself.” To understand this, think of how molecules bond together. Molecules resemble our solar system with the nucleus represented by our Sun (or a carbon atom in the image) and the electrons represent by the various planets. When one molecule “bonds” with another it is as if two solar systems’ planets became intertwined into each others orbits with both solar systems sharing certain planets and making the whole larger than the sum if it’s parts. When we use a cutting tool we are inducing these bonds to break apart. The “machinability” of a particular metal partially defines how easily the material separates from itself. The basic mechanics of forming a chip are the same regardless of the base material. As the cutting tool engages the workpiece, the material directly ahead of the tool is sheared and deformed under tremendous pressure. The deformed material then seeks to relieve its stressed condition by fracturing and flowing into the space above the tool in the form of a chip. The important difference is how the chip typically forms in various materials. Regardless of the tool being used or the metal being cut, the chip forming process occurs by a mechanism called plastic deformation. This deformation can be visualized as shearing. That is when a metal is subjected to a load exceeding its elastic limit. The crystals of the metal elongate through an action of slipping or shearing, which takes place within the crystals and between adjacent crystals. Type 1: Discontinuous ChipCast Iron, Hard Brass and other materials that produce a Powdery chip. “Discontinuous Chip - Discontinuous or segmented chips are produced when brittle metal such as cast iron and hard bronze are cut or when some ductile metals are cut under poor cutting conditions.
Type 2: Continuous ChipMedium to High carbon and alloy Steels – Long Chipping Materials “Continuous Chip - Continuous chips are a continuous ribbon produced when the flow of metal next to the tool face is not greatly restricted by a built-up edge or friction at the chip tool interface. The continuous ribbon chip is considered ideal for efficient cutting action because it results in better finishes. Unlike the Type 1 chip, fractures or ruptures do not occur here, because of the ductile nature of the metal.”
Type 3: Sheared ChipsLow carbon Steels, Stainless Steels, Nickel Alloys, Titanium, Copper, Aluminum and other soft, “gummy’ Materials. Sheared Chips or as some refer to it “Continuous Chip with a Built-up Edge (BUE). The metal ahead of the cutting tool is compressed and forms a chip which begins to flow along the chip-tool interface.
These metals readily deform in front of the cutting edge and have to be "sheared" by the tool. What the above paragraph doesn’t tell you is that these materials require tools with sharper cutting edges than those used for machining cast Iron or higher carbon content Steels. The chips tend to compress onto the face of the tool which can result in built-up edge.
The chips formed when cutting these metals are thicker than those produced by Medium Carbon or Alloy Steels at the same Feed Rates and Depths of Cut. These thicker chips are stronger and harder to break. Destiny Tool, through a combination of rake face geometry, carbide substrate and concentricity tolerance is able to enable the chip to more readily "separate from itself" which not only improves MRR, but also reduced heat into the end mill and thereby extends tool life as the feed rate increases. High strength metals such as Stainless Steel, Nickel Alloys and Titanium generate high heat and high cutting pressures in the area of the cutting edge. This results in reduced tool life compared to easier to machine materials.
0 Comments
What's a Nacelle?
The nacelle of a wind turbine houses the drive train and other tower-top components. It's critical that this drive train is in perfect alignment to insure optimal performance of the wind turbine. High quality Precision Brand Products slotted shim is the product of choice for this alignment job. How does the mechanic carry up and then make sure he's picking the correct size 280 feet in the air? He uses the new Precision Brand Products Up-Tower Shim Assortment! Contact Browne & Company for an authorized distributor near you. In January of this year we welcomed a new member to our Browne & Co. sales team and with manufacturing companies opening up again, it's about time we introduce you to Jeff Terrace!
Just before joining Browne & Co in January 2019, Jeff worked at Hoffmann Group, a German cutting tool, hand tool, workstation and storage solutions manufacturer. Jeff has been working as an InovaTool representative since February of 2019 and recently joined Browne & Company at the beginning of 2020 as our Cutting Tool Specialist. Please send Jeff and email or give him a call to introduce yourself or pick his brain about an application question. By Eric Brothers
On Saturday, May 30 at 3:22 p.m. EDT, SpaceX’s Falcon 9 launched Crew Dragon’s second demonstration (Demo-2) mission from Launch Complex 39A (LC-39A) at NASA’s Kennedy Space Center in Florida, and the next day Crew Dragon autonomously docked to the International Space Station (ISS). This test flight with NASA astronauts Bob Behnken and Doug Hurley on board the Dragon spacecraft returned human spaceflight to the United States. Demo-2 is the final major test for SpaceX’s human spaceflight system to be certified by NASA for operational crew missions to and from the ISS. SpaceX is returning human spaceflight to the United States, and NASA’s Commercial Crew Program is a turning point for America’s future in space exploration that lays the groundwork for future missions to the Moon, Mars, and beyond. Upon conclusion of the mission, Crew Dragon will autonomously undock with the two astronauts onboard the spacecraft and depart the Space Station. After jettisoning the trunk and conducting its deorbit burn, which lasts approximately 12 minutes, Dragon will reenter Earth’s atmosphere. Upon splashdown just off Florida’s Atlantic Coast, Dragon and the astronauts will be quickly recovered by SpaceX’s Go Navigator recovery vessel and returned to Cape Canaveral. |
AuthorWe've compiled the latest news and technical information about our principals and our market that we hope you find informative! Archives
May 2025
Categories
All
|