The method of evaluating the forming limit of sheet metal is using the forming limit diagram(FLD), and the test method for measuring forming limit curve(FLC) is ISO standardized. On the other hand, in the case of metal bulk materials, it was confirmed that the forming limit was defined by using various predictive models based on the ductile fracture theory. However it did not show a constant forming limit (limit damage value) depending on the shape of the specimen. Therefore, a study was conducted on the derivation of the triaxial stress curve to predict the fracture of the material for various stress triaxiality, not the existing limit damage value.

Graphite can be classified into natural graphite from mines and artificial graphite. Due to its outstanding properties such as light weight, thermal resistance, electrical conductivity, thermal conductivity, chemical stability, and high-temperature strength, artificial graphite is used across various industries in powder form and bulk form. Artificial graphite of powder form is usually used as anode materials for secondary cells, while artificial graphite of bulk form is used in steelmaking electrode bars, nuclear reactor moderators, silicon ingots for semiconductors, and manufacturing equipment. This study defines artificial graphite as bulk graphite, and provides an overview of bulk graphite manufacturing, including isotropic and anisotropic materials, molding methods, and heat treatment.

Titanium alloys are extensively used in high-temperature applications due to their excellent high strength andcorrosion resistance properties. However, titanium alloys are problematic because they tend to be extremely difficult-to-cut material. In this paper, the powder synthesis, spark plasma sintering (SPS), bulk material characteristics and machin-ability test of hybrid Ti2AlC ceramic bulk materials were systematically examined. The bulk samples mainly consistedof Ti2AlC materials with density close to theoretical value were synthesized by a SPS method. Random orientation andgood crystallization of the Ti2AlC was observed at 1100℃ for 10 min under SPS sintering conditions. Scanning electronmicroscopy results indicated a homogeneous distribution and nano-laminated structure of Ti2AlC MAX phase. The hard-ness and electrical conductivity of Ti2AlC were higher than that of Ti 6242 alloy at sintering temperature of 1000℃~1100℃. Consequently, the machinability of the hybrid Ti2AlC bulk materials is better than that of the Ti 6242 alloy formicro-EDM process of micro-hole shape workpiece.

This study introduces acceptance sampling plans and procedures for the inspection of bulk materials. This paper also presents statistical aspects of sampling bulk materials such as general principles and sampling of particulate materials.