Papers by Keyword: Cutting Performance

Abstract: The broaching process is widely used to generate irregular internal and external part features, therefore there is a demand for a broach with good broaching performance. Aiming at slowing broach surface wear degree and improving the tool life, this paper puts forward a inverted triangle textured broach which is based on the theory of metal cutting, friction study and contact mechanics. The broaching 45# steel load experiment was carried out. The broaching force and surface morphological changes were measured, and the cutting performance and wear characteristics of the textured broach tooth were analyzed by comparing with ordinary broach. Results show that the inverted triangle textured broach can reduce broaching load by 5%, and improve the response performance of broach for broaching load. The wear area and wear quantity of ordinary broach were larger than textured broach. The textured broach can greatly improve the cutting efficiency, reduce the tool wear and increase lifespan.

Abstract: This paper mainly analyzes the cutting mechanism of low temperature air cutting, and makes research and analysis about the brittle characteristics, the lubricate mechanism and the chip breaking mechanisms of metal materials under low temperature cold condition. Meanwhile, the cutting performance of typical difficult-to-machine materials, such as The precipitation stainless steel, super-alloy and titanium alloy, were discussed. Through cutting experiment under normal conditions and low temperature air conditions, the influence on cutting force, tool wear, chip shape and surface processing quality of typical difficult-to-machine materials were analyzed. The experimental results show that the low temperature air has better effects on cutting difficult-to-machine materials. It can reduce temperature distribution and cutting force, improve tool life and suface processing quality, decrease the use of cutting fluid and mitigate environmental pollution. Thus, low temperature air cutting is an efficient and environment friendly way to solve the problem of cutting difficult-to-machine materials.

Abstract: Material cutting properties can be judged by turning temperature and chip shape. A new method that can measure turning temperature more accurately was discussed in this paper. Compared with the traditional method, results show that turning temperature can be accurately measured through a new method in turning process. Turning temperature become stable and will not jump after 20s later. In addition, the higher the hardness, the higher the energy is needed, leading to the higher turning temperature. The average turning temperature of the quenched specimen, normalized specimen and annealed specimen measured through the new method is 100°C,70°Cand 60°C, respectively. And the chip morphologies of quenched specimen, normalized specimen and annealed specimen are irregular band chips, spiral debris chips and C-shaped chips, respectively.

Abstract: The evaluation of material cutting performance is a complicated and comprehensive process. Only by using the fuzzy comprehensive evaluation way can we get a satisfactory result. This essay, on the basis of fuzzy theory, illustrates the steps of fuzzy comprehensive evaluation, introduces the factors influencing 18Cr2NiWA's cutting processing performance, gives a fuzzy evaluation of the factors, and thereby successfully solves the problems regarding these multi-factors' decision and evaluation.

Abstract: A new developed TiN-TiB₂ ceramic cutting tool material (marked as TBN5) with high comprehensive mechanical properties was fabricated by the in-situ integration synthesis process. The cutting performance of TBN5 tool in continuously turning the austenitic stainless steel 1Cr18Ni9Ti was experimentally investigated; the failure modes and failure mechanisms of the cutting tool TBN5 were analyzed combined with its mechanical properties. Aiming at the materials removal amount, the optimal cutting parameters of TBN5 tool in turning 1Cr18Ni9Ti were firstly obtained by the orthogonal tests; and then with this cutting parameters, the cutting performance of TBN5 compared to the commercial tools LT55 and SG4 was studied. The results showed that the advanced tool TBN5 could get longer tool life than LT55 and SG4; the main failure modes of TBN5 were flank wear, breakage and the flaking of main cutting edge. The scope of its flaking was smaller and diffusion wear was not obvious, which was related to the higher fracture toughness and the higher thermal conductivity of TBN5.

Abstract: The nickel-based superalloy GH4033 is one of the difficult-to-cut materials. In order to investigate the machinability of GH4033, the tool cutting performance, tool failure modes, tool life and the relationships between surface roughness and tool flank wear were studied by using different coated cemented carbide cutting tools under dry cutting. Aiming at the amount of metal removal combining with the tool life and surface quality, the better cutting tool coating type and optimal cutting parameters were obtained through the orthogonal experiments. The results showed that the cutting performance of TiCN coated tool (GC4235) was better than that of TiAlN coated tool (JC450V). With these two kinds of tools, the machined surface roughness decreased to a minimum value and then increased with the increase of flank wear. When cutting GH4033, the main wear mechanism for both of the two types of tools included adhesive wear, diffusive wear, abrasive wear, edge wear and coating peeling.

Abstract: Silicon nitride cutting tool, which is widely applied to machine cast irons, is not suitable for steel cutting because of the massive chemical wear between silicon nitride and ferrous materials. Covering protective coating (s) on tool surface is an effective way to isolate the chemical contact between cutting tool and workpiece. The aim of this paper is to investigate the cutting performance and cutting mechanism of coated silicon nitride cutting tools on steel machining. The cutting performances of uncoated and CVD-Al₂O₃/TiN coated silicon nitride cutting tool when cutting high hardness alloy steel AISI 4340 under dry condition were investigated. Studies include tool flank wear, tribological behavior of the tool-chip interface and wear mechanisms for both uncoated and coated silicon nitride cutting tools. The results showed that the tool life of silicon nitride cutting tools can be improved to a great extent with the cover of CVD-Al₂O₃/TiN coating by avoiding crater failure and reducing friction during steel cutting.

Abstract: Large-sized spiral bevel gears are usually manufactured based on a cyclo-palloid system and have equi-depth teeth as well as a face hobbing system by a continuous cutting procedure using a special generator. It has been possible to machine the complicated shape because of the development of a multi-axis control and multi-tasking machine tool.The manufacturing method of the gears has been proposed using this development process. In this method, the spiral bevel gears are modeled based on a CAD system and are machined based on a CAM system. In this paper, the cutting performance in machining of the large-sized spiral bevel gears using the multi-axis control and multi-tasking machine toolis investigated. As a result, the relationship between the tool life of end mill and gear accuracy were made clear. The surface roughness and tool mark of the machined gears were compared with those using the special generator.

Abstract: In this paper, the oxide nanometer composite cutting performance of ceramic tools cutting cast iron were studied. And the tool failure modes were mainly analyzed. Through the study found that, with the increase of tool wear with cutting speed, failure forms mainly adhesion wear. When the cutting speed is low, the knife before the crater wear become the main form of ceramic cutting tool wear, boundary wear and the surface of the knife after wear is also very serious. And in the process of cutting, the collapse edge can also occur now; With the increase of cutting speed, collapse become the main failure forms of cutter blade.

Abstract: This study investigates the tool wear of PVD TiAlN multilayer coated end mill inserts when machining AISI D2 hardened steel in dry conditions. The experiment tests consisting three levels of cutting speed, V_c (80, 100, 120 m/min) and three levels of radial depth of cut, a_e (3, 4, 5 mm) was used for the study. The PVD TiAlN coated carbide insert performs satisfactory under the conditions tested, as reasonable tool life is recorded. By linking the machining tests and tool life curves, the wear behaviour of the coated insert was described. It is observed that wear of the tool mainly occurred on the flank wear. Tool life decreasing and volume material removal (VMR) increasing as cutting speed and radial depth of cut increased due to higher temperature generated and contact area immerse, respectively. Tool failure modes and wear mechanisms were examined at various cutting parameters. Built-up edge (BUE), groove and micro-chipping were found to be the predominant tool failure modes for cutting tools. The highest volume material removal, VMR attained was 3750 mm^3, meanwhile the higest tool life, T_L was 9.69 min.The combination of cutting conditions that gave the best response for different components of tool wear, tool life and surface integrity.