Additive Manufacturing for Enhanced Performance of Molds

AbstractAdditive manufactured conformal cooling channels has proved beneficial for molds used for casting. These casting tools often endure cyclic thermal influences that lead to thermal fatigue. To increase the structural resistance to thermal fatigue, the mold should be designed with some compliance for thermal expansion. This can be achieved by applying lattice structures in some sections of the mold. These structures may also be used as crack stoppers to prevent cooling fluid leakage. By use of complex internal structures, enhanced thermal management is possible. The manufacturing of molds is also faster, with less use of material

Formation of Built-Up Layer on the Tool in Turning Operation of Magnesium Alloys

The present work highlights some factors which affect formation of a protective built-up layer (BUL) on the rake face of the cutting tool when cutting magnesium alloys. This work suggests that BUL can positively affect tool life, surface roughness, cutting speed and tool forces. The BUL is formed in cutting magnesium alloys with the PCD tool inserts at cutting speed range from 500 to 2500 m/min and at the carbide tool inserts at lower cutting speed range around 550 m/min. It has been found that deposit layers primarily have similar chemical composition as MnAl inclusions which are incorporated in the structure of the examined AZ91 magnesium alloys

Estimation of minimum volume of bounding box for geometrical metrology

This paper presents algorithms for estimating the minimum volume bounding box based on a three-dimensional point set measured by a coordinate measuring machine. A new algorithm, which calculates the minimum volume with high accuracy and reduced number of computations, is developed. The algorithm is based on the convex hull operation and established theories about a minimum bounding box circumscribing a convex polyhedron. The new algorithm includes a pre-processing operation that removes convex polyhedron faces located near the edges of the measured object. As showed in the paper, the solution of the minimum bonding box is not based on faces located near the edges; therefore, we can save computation time by excluding them from the convex polyhedron data set. The algorithms have been demonstrated on physical objects measured by a coordinate measuring machine, and on theoretical 3D models. The results show that the algorithm can be used when high accuracy is required, for example in calibration of reference standards

Precision turning with instrumented vibration-damped boring bars

The paper presents the theoretical background and experimental results with a new approach for achieving high accuracy in finish turning with slender tools. The approach is developed especially for high-accuracy turning with vibration-damped boring bars with a length-to-diameter ratio up to 14, and equipment with strain sensors for in-process measurement of tool deflection. The approach is developed from an established three-pass method commonly used for precision turning with conventional slender tools without integrated sensors. It is shown that strain sensors can be utilized to achieve high accuracy in internal turning operations

High-Pressure Cooling in Turning of Inconel 625 with Ceramic Cutting Tools

Machining of heat resistant aerospace materials such as Inconel 625 or Inconel 718 is characterized by low cutting speeds, high tool wear rate, and high production costs. The machinability of heat resistant super alloys is low due to high hardness and low thermal conductivity of the nickel-based alloys. The paper presents a study on turning of Inconel 625 with ceramic cutting tools with different methods for application of cutting fluid. It is shown that high-pressure cooling gives excellent chip breaking. The tool life of ceramic cutting tools is not improved by increased coolant pressure

Estimation of minimum volume of bounding box for geometrical metrology

This paper presents algorithms for estimating the minimum volume bounding box based on a three-dimensional point set measured by a coordinate measuring machine. A new algorithm, which calculates the minimum volume with high accuracy and reduced number of computations, is developed. The algorithm is based on the convex hull operation and established theories about a minimum bounding box circumscribing a convex polyhedron. The new algorithm includes a pre-processing operation that removes convex polyhedron faces located near the edges of the measured object. As showed in the paper, the solution of the minimum bonding box is not based on faces located near the edges; therefore, we can save computation time by excluding them from the convex polyhedron data set. The algorithms have been demonstrated on physical objects measured by a coordinate measuring machine, and on theoretical 3D models. The results show that the algorithm can be used when high accuracy is required, for example in calibration of reference standards

High-Pressure Cooling in Turning of Inconel 625 with Ceramic Cutting Tools

Machining of heat resistant aerospace materials such as Inconel 625 or Inconel 718 is characterized by low cutting speeds, high tool wear rate, and high production costs. The machinability of heat resistant super alloys is low due to high hardness and low thermal conductivity of the nickel-based alloys. The paper presents a study on turning of Inconel 625 with ceramic cutting tools with different methods for application of cutting fluid. It is shown that high-pressure cooling gives excellent chip breaking. The tool life of ceramic cutting tools is not improved by increased coolant pressure.publishedVersion© 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/

Estimation of minimum volume of bounding box for geometrical metrology

This paper presents algorithms for estimating the minimum volume bounding box based on a three-dimensional point set measured by a coordinate measuring machine. A new algorithm, which calculates the minimum volume with high accuracy and reduced number of computations, is developed. The algorithm is based on the convex hull operation and established theories about a minimum bounding box circumscribing a convex polyhedron. The new algorithm includes a pre-processing operation that removes convex polyhedron faces located near the edges of the measured object. As showed in the paper, the solution of the minimum bonding box is not based on faces located near the edges; therefore, we can save computation time by excluding them from the convex polyhedron data set. The algorithms have been demonstrated on physical objects measured by a coordinate measuring machine, and on theoretical 3D models. The results show that the algorithm can be used when high accuracy is required, for example in calibration of reference standards

Precision turning with instrumented vibration-damped boring bars

The paper presents the theoretical background and experimental results with a new approach for achieving high accuracy in finish turning with slender tools. The approach is developed especially for high-accuracy turning with vibration-damped boring bars with a length-to-diameter ratio up to 14, and equipment with strain sensors for in-process measurement of tool deflection. The approach is developed from an established three-pass method commonly used for precision turning with conventional slender tools without integrated sensors. It is shown that strain sensors can be utilized to achieve high accuracy in internal turning operations.publishedVersion© 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/

High-Pressure Cooling in Turning of Inconel 625 with Ceramic Cutting Tools

Machining of heat resistant aerospace materials such as Inconel 625 or Inconel 718 is characterized by low cutting speeds, high tool wear rate, and high production costs. The machinability of heat resistant super alloys is low due to high hardness and low thermal conductivity of the nickel-based alloys. The paper presents a study on turning of Inconel 625 with ceramic cutting tools with different methods for application of cutting fluid. It is shown that high-pressure cooling gives excellent chip breaking. The tool life of ceramic cutting tools is not improved by increased coolant pressure.publishedVersion© 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/