Two-time Calibration at Both Ends for Sulfur Measurement by Using High Frequency Induction Infrared Absorption Method

High frequency induction heating infrared absorption method is a relative measurement method, and it requires calibrating the analyzer during the measurement process. Usually, one-time calibration on an analyzer is made for high sulfur value by using standard substances. The method proposed by this paper calibrates carbon-sulfur analyzers with a method of two-time calibration at both ends, which eliminates the impact of sulfur blank and thus improves the accuracy and precision of ultra-low sulfur measurement. The method extents the lower limit of measurement of sulfur in high temperature alloy, to 0.00005%, namely, 0.5ppm.

Design of Thermally Constrained High-Frequency Induction Heating System

One of the most prominent application areas of induction heating principle is for sealing of caps of plastic and glass containers. It is increasingly being used to seal containers with extremely wide range industrial products. The process ambience around the controller for sealing of bottles containing different types of products could be different. Such prospects, often, could act as constraints for design of power controllers. Dust prone environment prevailing in processes such as for sealing nutraceuticals, coffee, a few pharma products, etc. recommends use of air-tight enclosure. It does not have any ventilation, even the natural air movement inside or the free convection is restricted. This article proposes that the internal convection could still be made effective by creating requisite buoyant force where both power converter topology and component engineering could play important roles. The topology should optimally reduce the power loss and surface temperature of components should be high. The proposed idea has been validated by designing a zero-ventilated 1.5 kW, 50 kHz induction heating system that includes the induction coil head.

High-Frequency Induction Assisted Hybrid Friction Stir Welding of Inconel 718 Plates

The preheating system is a promising approach to decrease the axial load, improve the weld quality, and enhance the tool life during the friction stir welding of high strength material. In the present work, conventional friction stir welding (FSW) and high-frequency induction heating-assisted friction stir welding (I-FSW) systems were used to join 3 mm thick Inconel 718 plates with a WC-10%Co tool and studied their performances. The welding was carried out at a constant rotational speed of 300 rpm, including varying traverse speeds of 90 mm/min and 140 mm/min and varying preheating temperatures (310 oC, 410 oC, and 700 oC). The results show that good weld joints were possible at high traverse speed (i.e., 140 mm/min) using the I-FSW at low preheating temperature (i.e., 310 oC). Grain refinement in the weld zone with and without preheated FSW led to improved mechanical properties. The increased size of intermetallic phases and carbide particles due to induction preheating in I-FSW were most likely to be responsible for the enhancement of the weld strength. The hardness of the stir zone was increased from 250 HV to 370 HV, and the ultimate tensile strength of the I-FSW joint reaches 740 MPa, which was 98.8 % of the base material. The results also revealed that preheating affected the process temperature results lowering the axial force and frictional heat, which improved the tool life.

Design of Thermally Constrained High-Frequency Induction Heating System

One of the most prominent application areas of induction heating principle is for sealing of caps of plastic and glass containers. It is increasingly being used to seal containers with extremely wide range industrial products. The process ambience around the controller for sealing of bottles containing different types of products could be different. Such prospects, often, could act as constraints for design of power controllers. Dust prone environment prevailing in processes such as for sealing nutraceuticals, coffee, a few pharma products, etc. recommends use of air-tight enclosure. It does not have any ventilation, even the natural air movement inside or the free convection is restricted. This article proposes that the internal convection could still be made effective by creating requisite buoyant force where both power converter topology and component engineering could play important roles. The topology should optimally reduce the power loss and surface temperature of components should be high. The proposed idea has been validated by designing a zero-ventilated 1.5 kW, 50 kHz induction heating system that includes the induction coil head.

Design of Thermally Constrained High-Frequency Induction Heating System

One of the most prominent application areas of induction heating principle is for sealing of caps of plastic and glass containers. It is increasingly being used to seal containers with extremely wide range industrial products. The process ambience around the controller for sealing of bottles containing different types of products could be different. Such prospects, often, could act as constraints for design of power controllers. Dust prone environment prevailing in processes such as for sealing nutraceuticals, coffee, a few pharma products, etc. recommends use of air-tight enclosure. It does not have any ventilation, even the natural air movement inside or the free convection is restricted. This article proposes that the internal convection could still be made effective by creating requisite buoyant force where both power converter topology and component engineering could play important roles. The topology should optimally reduce the power loss and surface temperature of components should be high. The proposed idea has been validated by designing a zero-ventilated 1.5 kW, 50 kHz induction heating system that includes the induction coil head.

Mechanical Properties and Rapid Sintering of Nanostructured WC-Al2O3-Al Hard Materials

Nanostructured WC-Al2O3-Al composites was sintered using rapid high-frequency induction heated sintering (HFIHS) and the mechanical properties such as hardness and fracture toughness with consolidation were investigated. The HFIHS method induced a very fast densification nearly at the level of theoretical density and successfully prohibited grain growth, resulting in nano-sized grains. The fracture toughness was improved due to the consolidation facilitated by adding Al to WC-Al2O3 matrix. The WC-Al2O3 composites added with 5 and 10 vol.% Al showed higher hardness and fracture toughness compared with that of WC-Al2O3.

The Effect of Ball Milling on Properties and Sintering of Nanostructured TiB2

TiB2 powder was milled in a high-energy ball mill (Pulverisette-5 planetary mill) at 250 rpm for various time periods (0, 1, 4, and 10 h) and consolidated by the high frequency induction heated sintering (HFIHS). The effect of milling on the sintering behavior and crystallite size of TiB2 powders were investigated. A nanostructured dense TiB2 specimen with a relative density of up to 98% was readily achieved within very short time (two min). The ball milling effectively refined the crystallite structure of TiB2 powders and facilitated the subsequent consolidation. The sinter-onset temperature was reduced remarkably by the prior milling for 10 h. Accordingly, the relative density and mechanical properties of TiB2 compact increased as the milling time increased.