# A Multi-Model Ontological System for Intelligent Assistance in Laser Additive Processes
## 3 Results
### The Ontology of the Case Database
The essential characteristics of the substrate are the material (alloy) from which it is made, its geometric characteristics and its mass. The same characteristics are essential for the part being processed, but with the additional consideration that its functional surface material (if any) may differ from the bulk material. The process gas can be either a monogas or a multicomponent gas mixture. In the equipment for performing the TO section, the technological equipment used for carrying out the operation is specified by selecting it from the appropriate reference databases. The preliminary preparation of the substrate section is completed if the substrate (rather than a part) is the object of processing (e.g., in certain research applications). Substrate specifications are not duplicated here if already defined in the terms of reference. However, mandatory pre-processing conditions (such as controlled heating of the substrate to specified temperatures at a certain heating rate before starting the process) must be documented here if applicable. If the substrate has not been specified in the terms of reference, then the characteristics listed in the terms of reference for performing the TO should be specified here. Controlled heating is characterized by the temperature to which the substrate should be heated, as well as by the heating rate. The temperature value is usually the numerical range that needs to be maintained during processing. If a part (not a substrate) was specified as the processing object in the terms of reference, then information about controlled heating of the part can be documented in the preliminary preparation of the part section. Controlled heating is required, first of all, for massive parts with high thermal conductivity, in order to bring the crystal structure of the material to a certain energy state prior to focused radiation processing. The gas environment in the working chamber section must be completed when a \"global\" protective gas environment is created in a working chamber during the TO--in addition to the shielding gas/gas mixture. The latter is delivered through the gas-powder mixture supply unit and forms a \"local\" protection of the melt pool and of solidification zone. The working chamber gas environment specification includes information about which filling process gas--monogas or a gas mixture--was used to create the environment, as well as parameters such as the volume flow rate, the pressure and the temperature of the gas. In the case of using a gas mixture, the percentage is indicated (i.e., the volume fraction of each monogas in it). The key parameters of the TO section consist of four subsections: laser emission parameters; process gas supply parameters; material feeding parameters and parameters of positioning and movement of the laser optical head (relative to the processed surface). The key parameters of laser emission include the mode of radiation generation (continuous, modulated, pulsed), its power, and the beam spot diameter on the processed surface. For modulated and pulsed modes, the pulse duration and, accordingly, the modulation frequency of the output power/pulse frequency are also important characteristics. The process gas supply parameters section consists of three subsections: parameters of the shielding gas environment (providing \"local\" protection of the melt pool and of solidification zone), parameters of the carrier gas and parameters of the auxiliary (shaping) gas. The structure of the information for describing the shielding gas environment coincides with the structure of the information for describing the gas environment created in the working chamber. The carrier and auxiliary gases are monogases; their key parameters are the volume flow rate, the pressure and the temperature. The material feeding parameters section comprises two mutually exclusive options: metal powder material and metal wire material.