From Teflpedia

An affricate (/ˈæfrɪkət/) is a consonant sound that begins as a stop sound and releases as a fricative, generally with the same place of articulation.

There are two affricates in standard English phonemes, both of which are palato-alveolar affricates, which come in two varieties, unvoiced /ʧ/ and a voiced /ʤ/.

Other affricates are occasionally produced in English but are usually thought of as two consonant sounds and represented by two phonemes; the alveolar affricates /ts/ and /dz/.